--- /dev/null
+ Uprobe-tracer: Uprobe-based Event Tracing
+ =========================================
+ Documentation written by Srikar Dronamraju
+
+Overview
+--------
+Uprobe based trace events are similar to kprobe based trace events.
+To enable this feature, build your kernel with CONFIG_UPROBE_EVENT=y.
+
+Similar to the kprobe-event tracer, this doesn't need to be activated via
+current_tracer. Instead of that, add probe points via
+/sys/kernel/debug/tracing/uprobe_events, and enable it via
+/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled.
+
+However unlike kprobe-event tracer, the uprobe event interface expects the
+user to calculate the offset of the probepoint in the object
+
+Synopsis of uprobe_tracer
+-------------------------
+ p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe
+
+ GRP : Group name. If omitted, use "uprobes" for it.
+ EVENT : Event name. If omitted, the event name is generated
+ based on SYMBOL+offs.
+ PATH : path to an executable or a library.
+ SYMBOL[+offs] : Symbol+offset where the probe is inserted.
+
+ FETCHARGS : Arguments. Each probe can have up to 128 args.
+ %REG : Fetch register REG
+
+Event Profiling
+---------------
+ You can check the total number of probe hits and probe miss-hits via
+/sys/kernel/debug/tracing/uprobe_profile.
+ The first column is event name, the second is the number of probe hits,
+the third is the number of probe miss-hits.
+
+Usage examples
+--------------
+To add a probe as a new event, write a new definition to uprobe_events
+as below.
+
+ echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events
+
+ This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash
+
+ echo > /sys/kernel/debug/tracing/uprobe_events
+
+ This clears all probe points.
+
+The following example shows how to dump the instruction pointer and %ax
+a register at the probed text address. Here we are trying to probe
+function zfree in /bin/zsh
+
+ # cd /sys/kernel/debug/tracing/
+ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp
+ 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh
+ # objdump -T /bin/zsh | grep -w zfree
+ 0000000000446420 g DF .text 0000000000000012 Base zfree
+
+0x46420 is the offset of zfree in object /bin/zsh that is loaded at
+0x00400000. Hence the command to probe would be :
+
+ # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
+
+Please note: User has to explicitly calculate the offset of the probepoint
+in the object. We can see the events that are registered by looking at the
+uprobe_events file.
+
+ # cat uprobe_events
+ p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax
+
+The format of events can be seen by viewing the file events/uprobes/p_zsh_0x46420/format
+
+ # cat events/uprobes/p_zsh_0x46420/format
+ name: p_zsh_0x46420
+ ID: 922
+ format:
+ field:unsigned short common_type; offset:0; size:2; signed:0;
+ field:unsigned char common_flags; offset:2; size:1; signed:0;
+ field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
+ field:int common_pid; offset:4; size:4; signed:1;
+ field:int common_padding; offset:8; size:4; signed:1;
+
+ field:unsigned long __probe_ip; offset:12; size:4; signed:0;
+ field:u32 arg1; offset:16; size:4; signed:0;
+ field:u32 arg2; offset:20; size:4; signed:0;
+
+ print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2
+
+Right after definition, each event is disabled by default. For tracing these
+events, you need to enable it by:
+
+ # echo 1 > events/uprobes/enable
+
+Lets disable the event after sleeping for some time.
+ # sleep 20
+ # echo 0 > events/uprobes/enable
+
+And you can see the traced information via /sys/kernel/debug/tracing/trace.
+
+ # cat trace
+ # tracer: nop
+ #
+ # TASK-PID CPU# TIMESTAMP FUNCTION
+ # | | | | |
+ zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
+ zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
+ zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
+ zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
+
+Each line shows us probes were triggered for a pid 24842 with ip being
+0x446421 and contents of ax register being 79.
depends on KPROBES && HAVE_OPTPROBES
depends on !PREEMPT
+config UPROBES
+ bool "Transparent user-space probes (EXPERIMENTAL)"
+ depends on UPROBE_EVENT && PERF_EVENTS
+ default n
+ help
+ Uprobes is the user-space counterpart to kprobes: they
+ enable instrumentation applications (such as 'perf probe')
+ to establish unintrusive probes in user-space binaries and
+ libraries, by executing handler functions when the probes
+ are hit by user-space applications.
+
+ ( These probes come in the form of single-byte breakpoints,
+ managed by the kernel and kept transparent to the probed
+ application. )
+
+ If in doubt, say "N".
+
config HAVE_EFFICIENT_UNALIGNED_ACCESS
bool
help
select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
config INSTRUCTION_DECODER
- def_bool (KPROBES || PERF_EVENTS)
+ def_bool (KPROBES || PERF_EVENTS || UPROBES)
config OUTPUT_FORMAT
string
def_bool y
depends on HOTPLUG_CPU
+config ARCH_SUPPORTS_UPROBES
+ def_bool y
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
+#define TIF_UPROBE 12 /* breakpointed or singlestepping */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* IA32 compatibility process */
#define TIF_FORK 18 /* ret_from_fork */
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
+#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_FORK (1 << TIF_FORK)
--- /dev/null
+#ifndef _ASM_UPROBES_H
+#define _ASM_UPROBES_H
+/*
+ * User-space Probes (UProbes) for x86
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2008-2011
+ * Authors:
+ * Srikar Dronamraju
+ * Jim Keniston
+ */
+
+#include <linux/notifier.h>
+
+typedef u8 uprobe_opcode_t;
+
+#define MAX_UINSN_BYTES 16
+#define UPROBE_XOL_SLOT_BYTES 128 /* to keep it cache aligned */
+
+#define UPROBE_SWBP_INSN 0xcc
+#define UPROBE_SWBP_INSN_SIZE 1
+
+struct arch_uprobe {
+ u16 fixups;
+ u8 insn[MAX_UINSN_BYTES];
+#ifdef CONFIG_X86_64
+ unsigned long rip_rela_target_address;
+#endif
+};
+
+struct arch_uprobe_task {
+ unsigned long saved_trap_nr;
+#ifdef CONFIG_X86_64
+ unsigned long saved_scratch_register;
+#endif
+};
+
+extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm);
+extern int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);
+extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
+extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
+extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
+extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
+#endif /* _ASM_UPROBES_H */
obj-$(CONFIG_SWIOTLB) += pci-swiotlb.o
obj-$(CONFIG_OF) += devicetree.o
+obj-$(CONFIG_UPROBES) += uprobes.o
###
# 64 bit specific files
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/user-return-notifier.h>
+#include <linux/uprobes.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+ if (thread_info_flags & _TIF_UPROBE) {
+ clear_thread_flag(TIF_UPROBE);
+ uprobe_notify_resume(regs);
+ }
+
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
--- /dev/null
+/*
+ * User-space Probes (UProbes) for x86
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2008-2011
+ * Authors:
+ * Srikar Dronamraju
+ * Jim Keniston
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/uprobes.h>
+#include <linux/uaccess.h>
+
+#include <linux/kdebug.h>
+#include <asm/processor.h>
+#include <asm/insn.h>
+
+/* Post-execution fixups. */
+
+/* No fixup needed */
+#define UPROBE_FIX_NONE 0x0
+
+/* Adjust IP back to vicinity of actual insn */
+#define UPROBE_FIX_IP 0x1
+
+/* Adjust the return address of a call insn */
+#define UPROBE_FIX_CALL 0x2
+
+#define UPROBE_FIX_RIP_AX 0x8000
+#define UPROBE_FIX_RIP_CX 0x4000
+
+#define UPROBE_TRAP_NR UINT_MAX
+
+/* Adaptations for mhiramat x86 decoder v14. */
+#define OPCODE1(insn) ((insn)->opcode.bytes[0])
+#define OPCODE2(insn) ((insn)->opcode.bytes[1])
+#define OPCODE3(insn) ((insn)->opcode.bytes[2])
+#define MODRM_REG(insn) X86_MODRM_REG(insn->modrm.value)
+
+#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
+ (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
+ (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
+ (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
+ (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
+ << (row % 32))
+
+/*
+ * Good-instruction tables for 32-bit apps. This is non-const and volatile
+ * to keep gcc from statically optimizing it out, as variable_test_bit makes
+ * some versions of gcc to think only *(unsigned long*) is used.
+ */
+static volatile u32 good_insns_32[256 / 32] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ---------------------------------------------- */
+ W(0x00, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0) | /* 00 */
+ W(0x10, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0) , /* 10 */
+ W(0x20, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1) | /* 20 */
+ W(0x30, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1) , /* 30 */
+ W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */
+ W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 50 */
+ W(0x60, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 60 */
+ W(0x70, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 70 */
+ W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
+ W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
+ W(0xa0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* a0 */
+ W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* b0 */
+ W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0) | /* c0 */
+ W(0xd0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
+ W(0xe0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* e0 */
+ W(0xf0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1) /* f0 */
+ /* ---------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+
+/* Using this for both 64-bit and 32-bit apps */
+static volatile u32 good_2byte_insns[256 / 32] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ---------------------------------------------- */
+ W(0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1) | /* 00 */
+ W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1) , /* 10 */
+ W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 20 */
+ W(0x30, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */
+ W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */
+ W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 50 */
+ W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 60 */
+ W(0x70, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */
+ W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
+ W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
+ W(0xa0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1) | /* a0 */
+ W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1) , /* b0 */
+ W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */
+ W(0xd0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
+ W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* e0 */
+ W(0xf0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* f0 */
+ /* ---------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+
+#ifdef CONFIG_X86_64
+/* Good-instruction tables for 64-bit apps */
+static volatile u32 good_insns_64[256 / 32] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ---------------------------------------------- */
+ W(0x00, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0) | /* 00 */
+ W(0x10, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0) , /* 10 */
+ W(0x20, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0) | /* 20 */
+ W(0x30, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0) , /* 30 */
+ W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */
+ W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 50 */
+ W(0x60, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 60 */
+ W(0x70, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 70 */
+ W(0x80, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
+ W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
+ W(0xa0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* a0 */
+ W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* b0 */
+ W(0xc0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0) | /* c0 */
+ W(0xd0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
+ W(0xe0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* e0 */
+ W(0xf0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1) /* f0 */
+ /* ---------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+#endif
+#undef W
+
+/*
+ * opcodes we'll probably never support:
+ *
+ * 6c-6d, e4-e5, ec-ed - in
+ * 6e-6f, e6-e7, ee-ef - out
+ * cc, cd - int3, int
+ * cf - iret
+ * d6 - illegal instruction
+ * f1 - int1/icebp
+ * f4 - hlt
+ * fa, fb - cli, sti
+ * 0f - lar, lsl, syscall, clts, sysret, sysenter, sysexit, invd, wbinvd, ud2
+ *
+ * invalid opcodes in 64-bit mode:
+ *
+ * 06, 0e, 16, 1e, 27, 2f, 37, 3f, 60-62, 82, c4-c5, d4-d5
+ * 63 - we support this opcode in x86_64 but not in i386.
+ *
+ * opcodes we may need to refine support for:
+ *
+ * 0f - 2-byte instructions: For many of these instructions, the validity
+ * depends on the prefix and/or the reg field. On such instructions, we
+ * just consider the opcode combination valid if it corresponds to any
+ * valid instruction.
+ *
+ * 8f - Group 1 - only reg = 0 is OK
+ * c6-c7 - Group 11 - only reg = 0 is OK
+ * d9-df - fpu insns with some illegal encodings
+ * f2, f3 - repnz, repz prefixes. These are also the first byte for
+ * certain floating-point instructions, such as addsd.
+ *
+ * fe - Group 4 - only reg = 0 or 1 is OK
+ * ff - Group 5 - only reg = 0-6 is OK
+ *
+ * others -- Do we need to support these?
+ *
+ * 0f - (floating-point?) prefetch instructions
+ * 07, 17, 1f - pop es, pop ss, pop ds
+ * 26, 2e, 36, 3e - es:, cs:, ss:, ds: segment prefixes --
+ * but 64 and 65 (fs: and gs:) seem to be used, so we support them
+ * 67 - addr16 prefix
+ * ce - into
+ * f0 - lock prefix
+ */
+
+/*
+ * TODO:
+ * - Where necessary, examine the modrm byte and allow only valid instructions
+ * in the different Groups and fpu instructions.
+ */
+
+static bool is_prefix_bad(struct insn *insn)
+{
+ int i;
+
+ for (i = 0; i < insn->prefixes.nbytes; i++) {
+ switch (insn->prefixes.bytes[i]) {
+ case 0x26: /* INAT_PFX_ES */
+ case 0x2E: /* INAT_PFX_CS */
+ case 0x36: /* INAT_PFX_DS */
+ case 0x3E: /* INAT_PFX_SS */
+ case 0xF0: /* INAT_PFX_LOCK */
+ return true;
+ }
+ }
+ return false;
+}
+
+static int validate_insn_32bits(struct arch_uprobe *auprobe, struct insn *insn)
+{
+ insn_init(insn, auprobe->insn, false);
+
+ /* Skip good instruction prefixes; reject "bad" ones. */
+ insn_get_opcode(insn);
+ if (is_prefix_bad(insn))
+ return -ENOTSUPP;
+
+ if (test_bit(OPCODE1(insn), (unsigned long *)good_insns_32))
+ return 0;
+
+ if (insn->opcode.nbytes == 2) {
+ if (test_bit(OPCODE2(insn), (unsigned long *)good_2byte_insns))
+ return 0;
+ }
+
+ return -ENOTSUPP;
+}
+
+/*
+ * Figure out which fixups arch_uprobe_post_xol() will need to perform, and
+ * annotate arch_uprobe->fixups accordingly. To start with,
+ * arch_uprobe->fixups is either zero or it reflects rip-related fixups.
+ */
+static void prepare_fixups(struct arch_uprobe *auprobe, struct insn *insn)
+{
+ bool fix_ip = true, fix_call = false; /* defaults */
+ int reg;
+
+ insn_get_opcode(insn); /* should be a nop */
+
+ switch (OPCODE1(insn)) {
+ case 0xc3: /* ret/lret */
+ case 0xcb:
+ case 0xc2:
+ case 0xca:
+ /* ip is correct */
+ fix_ip = false;
+ break;
+ case 0xe8: /* call relative - Fix return addr */
+ fix_call = true;
+ break;
+ case 0x9a: /* call absolute - Fix return addr, not ip */
+ fix_call = true;
+ fix_ip = false;
+ break;
+ case 0xff:
+ insn_get_modrm(insn);
+ reg = MODRM_REG(insn);
+ if (reg == 2 || reg == 3) {
+ /* call or lcall, indirect */
+ /* Fix return addr; ip is correct. */
+ fix_call = true;
+ fix_ip = false;
+ } else if (reg == 4 || reg == 5) {
+ /* jmp or ljmp, indirect */
+ /* ip is correct. */
+ fix_ip = false;
+ }
+ break;
+ case 0xea: /* jmp absolute -- ip is correct */
+ fix_ip = false;
+ break;
+ default:
+ break;
+ }
+ if (fix_ip)
+ auprobe->fixups |= UPROBE_FIX_IP;
+ if (fix_call)
+ auprobe->fixups |= UPROBE_FIX_CALL;
+}
+
+#ifdef CONFIG_X86_64
+/*
+ * If arch_uprobe->insn doesn't use rip-relative addressing, return
+ * immediately. Otherwise, rewrite the instruction so that it accesses
+ * its memory operand indirectly through a scratch register. Set
+ * arch_uprobe->fixups and arch_uprobe->rip_rela_target_address
+ * accordingly. (The contents of the scratch register will be saved
+ * before we single-step the modified instruction, and restored
+ * afterward.)
+ *
+ * We do this because a rip-relative instruction can access only a
+ * relatively small area (+/- 2 GB from the instruction), and the XOL
+ * area typically lies beyond that area. At least for instructions
+ * that store to memory, we can't execute the original instruction
+ * and "fix things up" later, because the misdirected store could be
+ * disastrous.
+ *
+ * Some useful facts about rip-relative instructions:
+ *
+ * - There's always a modrm byte.
+ * - There's never a SIB byte.
+ * - The displacement is always 4 bytes.
+ */
+static void
+handle_riprel_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+{
+ u8 *cursor;
+ u8 reg;
+
+ if (mm->context.ia32_compat)
+ return;
+
+ auprobe->rip_rela_target_address = 0x0;
+ if (!insn_rip_relative(insn))
+ return;
+
+ /*
+ * insn_rip_relative() would have decoded rex_prefix, modrm.
+ * Clear REX.b bit (extension of MODRM.rm field):
+ * we want to encode rax/rcx, not r8/r9.
+ */
+ if (insn->rex_prefix.nbytes) {
+ cursor = auprobe->insn + insn_offset_rex_prefix(insn);
+ *cursor &= 0xfe; /* Clearing REX.B bit */
+ }
+
+ /*
+ * Point cursor at the modrm byte. The next 4 bytes are the
+ * displacement. Beyond the displacement, for some instructions,
+ * is the immediate operand.
+ */
+ cursor = auprobe->insn + insn_offset_modrm(insn);
+ insn_get_length(insn);
+
+ /*
+ * Convert from rip-relative addressing to indirect addressing
+ * via a scratch register. Change the r/m field from 0x5 (%rip)
+ * to 0x0 (%rax) or 0x1 (%rcx), and squeeze out the offset field.
+ */
+ reg = MODRM_REG(insn);
+ if (reg == 0) {
+ /*
+ * The register operand (if any) is either the A register
+ * (%rax, %eax, etc.) or (if the 0x4 bit is set in the
+ * REX prefix) %r8. In any case, we know the C register
+ * is NOT the register operand, so we use %rcx (register
+ * #1) for the scratch register.
+ */
+ auprobe->fixups = UPROBE_FIX_RIP_CX;
+ /* Change modrm from 00 000 101 to 00 000 001. */
+ *cursor = 0x1;
+ } else {
+ /* Use %rax (register #0) for the scratch register. */
+ auprobe->fixups = UPROBE_FIX_RIP_AX;
+ /* Change modrm from 00 xxx 101 to 00 xxx 000 */
+ *cursor = (reg << 3);
+ }
+
+ /* Target address = address of next instruction + (signed) offset */
+ auprobe->rip_rela_target_address = (long)insn->length + insn->displacement.value;
+
+ /* Displacement field is gone; slide immediate field (if any) over. */
+ if (insn->immediate.nbytes) {
+ cursor++;
+ memmove(cursor, cursor + insn->displacement.nbytes, insn->immediate.nbytes);
+ }
+ return;
+}
+
+static int validate_insn_64bits(struct arch_uprobe *auprobe, struct insn *insn)
+{
+ insn_init(insn, auprobe->insn, true);
+
+ /* Skip good instruction prefixes; reject "bad" ones. */
+ insn_get_opcode(insn);
+ if (is_prefix_bad(insn))
+ return -ENOTSUPP;
+
+ if (test_bit(OPCODE1(insn), (unsigned long *)good_insns_64))
+ return 0;
+
+ if (insn->opcode.nbytes == 2) {
+ if (test_bit(OPCODE2(insn), (unsigned long *)good_2byte_insns))
+ return 0;
+ }
+ return -ENOTSUPP;
+}
+
+static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+{
+ if (mm->context.ia32_compat)
+ return validate_insn_32bits(auprobe, insn);
+ return validate_insn_64bits(auprobe, insn);
+}
+#else /* 32-bit: */
+static void handle_riprel_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+{
+ /* No RIP-relative addressing on 32-bit */
+}
+
+static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+{
+ return validate_insn_32bits(auprobe, insn);
+}
+#endif /* CONFIG_X86_64 */
+
+/**
+ * arch_uprobe_analyze_insn - instruction analysis including validity and fixups.
+ * @mm: the probed address space.
+ * @arch_uprobe: the probepoint information.
+ * Return 0 on success or a -ve number on error.
+ */
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm)
+{
+ int ret;
+ struct insn insn;
+
+ auprobe->fixups = 0;
+ ret = validate_insn_bits(auprobe, mm, &insn);
+ if (ret != 0)
+ return ret;
+
+ handle_riprel_insn(auprobe, mm, &insn);
+ prepare_fixups(auprobe, &insn);
+
+ return 0;
+}
+
+#ifdef CONFIG_X86_64
+/*
+ * If we're emulating a rip-relative instruction, save the contents
+ * of the scratch register and store the target address in that register.
+ */
+static void
+pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs,
+ struct arch_uprobe_task *autask)
+{
+ if (auprobe->fixups & UPROBE_FIX_RIP_AX) {
+ autask->saved_scratch_register = regs->ax;
+ regs->ax = current->utask->vaddr;
+ regs->ax += auprobe->rip_rela_target_address;
+ } else if (auprobe->fixups & UPROBE_FIX_RIP_CX) {
+ autask->saved_scratch_register = regs->cx;
+ regs->cx = current->utask->vaddr;
+ regs->cx += auprobe->rip_rela_target_address;
+ }
+}
+#else
+static void
+pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs,
+ struct arch_uprobe_task *autask)
+{
+ /* No RIP-relative addressing on 32-bit */
+}
+#endif
+
+/*
+ * arch_uprobe_pre_xol - prepare to execute out of line.
+ * @auprobe: the probepoint information.
+ * @regs: reflects the saved user state of current task.
+ */
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct arch_uprobe_task *autask;
+
+ autask = ¤t->utask->autask;
+ autask->saved_trap_nr = current->thread.trap_nr;
+ current->thread.trap_nr = UPROBE_TRAP_NR;
+ regs->ip = current->utask->xol_vaddr;
+ pre_xol_rip_insn(auprobe, regs, autask);
+
+ return 0;
+}
+
+/*
+ * This function is called by arch_uprobe_post_xol() to adjust the return
+ * address pushed by a call instruction executed out of line.
+ */
+static int adjust_ret_addr(unsigned long sp, long correction)
+{
+ int rasize, ncopied;
+ long ra = 0;
+
+ if (is_ia32_task())
+ rasize = 4;
+ else
+ rasize = 8;
+
+ ncopied = copy_from_user(&ra, (void __user *)sp, rasize);
+ if (unlikely(ncopied))
+ return -EFAULT;
+
+ ra += correction;
+ ncopied = copy_to_user((void __user *)sp, &ra, rasize);
+ if (unlikely(ncopied))
+ return -EFAULT;
+
+ return 0;
+}
+
+#ifdef CONFIG_X86_64
+static bool is_riprel_insn(struct arch_uprobe *auprobe)
+{
+ return ((auprobe->fixups & (UPROBE_FIX_RIP_AX | UPROBE_FIX_RIP_CX)) != 0);
+}
+
+static void
+handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction)
+{
+ if (is_riprel_insn(auprobe)) {
+ struct arch_uprobe_task *autask;
+
+ autask = ¤t->utask->autask;
+ if (auprobe->fixups & UPROBE_FIX_RIP_AX)
+ regs->ax = autask->saved_scratch_register;
+ else
+ regs->cx = autask->saved_scratch_register;
+
+ /*
+ * The original instruction includes a displacement, and so
+ * is 4 bytes longer than what we've just single-stepped.
+ * Fall through to handle stuff like "jmpq *...(%rip)" and
+ * "callq *...(%rip)".
+ */
+ if (correction)
+ *correction += 4;
+ }
+}
+#else
+static void
+handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction)
+{
+ /* No RIP-relative addressing on 32-bit */
+}
+#endif
+
+/*
+ * If xol insn itself traps and generates a signal(Say,
+ * SIGILL/SIGSEGV/etc), then detect the case where a singlestepped
+ * instruction jumps back to its own address. It is assumed that anything
+ * like do_page_fault/do_trap/etc sets thread.trap_nr != -1.
+ *
+ * arch_uprobe_pre_xol/arch_uprobe_post_xol save/restore thread.trap_nr,
+ * arch_uprobe_xol_was_trapped() simply checks that ->trap_nr is not equal to
+ * UPROBE_TRAP_NR == -1 set by arch_uprobe_pre_xol().
+ */
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+ if (t->thread.trap_nr != UPROBE_TRAP_NR)
+ return true;
+
+ return false;
+}
+
+/*
+ * Called after single-stepping. To avoid the SMP problems that can
+ * occur when we temporarily put back the original opcode to
+ * single-step, we single-stepped a copy of the instruction.
+ *
+ * This function prepares to resume execution after the single-step.
+ * We have to fix things up as follows:
+ *
+ * Typically, the new ip is relative to the copied instruction. We need
+ * to make it relative to the original instruction (FIX_IP). Exceptions
+ * are return instructions and absolute or indirect jump or call instructions.
+ *
+ * If the single-stepped instruction was a call, the return address that
+ * is atop the stack is the address following the copied instruction. We
+ * need to make it the address following the original instruction (FIX_CALL).
+ *
+ * If the original instruction was a rip-relative instruction such as
+ * "movl %edx,0xnnnn(%rip)", we have instead executed an equivalent
+ * instruction using a scratch register -- e.g., "movl %edx,(%rax)".
+ * We need to restore the contents of the scratch register and adjust
+ * the ip, keeping in mind that the instruction we executed is 4 bytes
+ * shorter than the original instruction (since we squeezed out the offset
+ * field). (FIX_RIP_AX or FIX_RIP_CX)
+ */
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask;
+ long correction;
+ int result = 0;
+
+ WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
+
+ utask = current->utask;
+ current->thread.trap_nr = utask->autask.saved_trap_nr;
+ correction = (long)(utask->vaddr - utask->xol_vaddr);
+ handle_riprel_post_xol(auprobe, regs, &correction);
+ if (auprobe->fixups & UPROBE_FIX_IP)
+ regs->ip += correction;
+
+ if (auprobe->fixups & UPROBE_FIX_CALL)
+ result = adjust_ret_addr(regs->sp, correction);
+
+ return result;
+}
+
+/* callback routine for handling exceptions. */
+int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data)
+{
+ struct die_args *args = data;
+ struct pt_regs *regs = args->regs;
+ int ret = NOTIFY_DONE;
+
+ /* We are only interested in userspace traps */
+ if (regs && !user_mode_vm(regs))
+ return NOTIFY_DONE;
+
+ switch (val) {
+ case DIE_INT3:
+ if (uprobe_pre_sstep_notifier(regs))
+ ret = NOTIFY_STOP;
+
+ break;
+
+ case DIE_DEBUG:
+ if (uprobe_post_sstep_notifier(regs))
+ ret = NOTIFY_STOP;
+
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * This function gets called when XOL instruction either gets trapped or
+ * the thread has a fatal signal, so reset the instruction pointer to its
+ * probed address.
+ */
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ current->thread.trap_nr = utask->autask.saved_trap_nr;
+ handle_riprel_post_xol(auprobe, regs, NULL);
+ instruction_pointer_set(regs, utask->vaddr);
+}
+
+/*
+ * Skip these instructions as per the currently known x86 ISA.
+ * 0x66* { 0x90 | 0x0f 0x1f | 0x0f 0x19 | 0x87 0xc0 }
+ */
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ int i;
+
+ for (i = 0; i < MAX_UINSN_BYTES; i++) {
+ if ((auprobe->insn[i] == 0x66))
+ continue;
+
+ if (auprobe->insn[i] == 0x90)
+ return true;
+
+ if (i == (MAX_UINSN_BYTES - 1))
+ break;
+
+ if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x1f))
+ return true;
+
+ if ((auprobe->insn[i] == 0x0f) && (auprobe->insn[i+1] == 0x19))
+ return true;
+
+ if ((auprobe->insn[i] == 0x87) && (auprobe->insn[i+1] == 0xc0))
+ return true;
+
+ break;
+ }
+ return false;
+}
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/page-debug-flags.h>
+#include <linux/uprobes.h>
#include <asm/page.h>
#include <asm/mmu.h>
#ifdef CONFIG_CPUMASK_OFFSTACK
struct cpumask cpumask_allocation;
#endif
+ struct uprobes_state uprobes_state;
};
static inline void mm_init_cpumask(struct mm_struct *mm)
#ifdef CONFIG_HAVE_HW_BREAKPOINT
atomic_t ptrace_bp_refcnt;
#endif
+#ifdef CONFIG_UPROBES
+ struct uprobe_task *utask;
+ int uprobe_srcu_id;
+#endif
};
/* Future-safe accessor for struct task_struct's cpus_allowed. */
--- /dev/null
+#ifndef _LINUX_UPROBES_H
+#define _LINUX_UPROBES_H
+/*
+ * User-space Probes (UProbes)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2008-2012
+ * Authors:
+ * Srikar Dronamraju
+ * Jim Keniston
+ * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/rbtree.h>
+
+struct vm_area_struct;
+struct mm_struct;
+struct inode;
+
+#ifdef CONFIG_ARCH_SUPPORTS_UPROBES
+# include <asm/uprobes.h>
+#endif
+
+/* flags that denote/change uprobes behaviour */
+
+/* Have a copy of original instruction */
+#define UPROBE_COPY_INSN 0x1
+
+/* Dont run handlers when first register/ last unregister in progress*/
+#define UPROBE_RUN_HANDLER 0x2
+/* Can skip singlestep */
+#define UPROBE_SKIP_SSTEP 0x4
+
+struct uprobe_consumer {
+ int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
+ /*
+ * filter is optional; If a filter exists, handler is run
+ * if and only if filter returns true.
+ */
+ bool (*filter)(struct uprobe_consumer *self, struct task_struct *task);
+
+ struct uprobe_consumer *next;
+};
+
+#ifdef CONFIG_UPROBES
+enum uprobe_task_state {
+ UTASK_RUNNING,
+ UTASK_BP_HIT,
+ UTASK_SSTEP,
+ UTASK_SSTEP_ACK,
+ UTASK_SSTEP_TRAPPED,
+};
+
+/*
+ * uprobe_task: Metadata of a task while it singlesteps.
+ */
+struct uprobe_task {
+ enum uprobe_task_state state;
+ struct arch_uprobe_task autask;
+
+ struct uprobe *active_uprobe;
+
+ unsigned long xol_vaddr;
+ unsigned long vaddr;
+};
+
+/*
+ * On a breakpoint hit, thread contests for a slot. It frees the
+ * slot after singlestep. Currently a fixed number of slots are
+ * allocated.
+ */
+struct xol_area {
+ wait_queue_head_t wq; /* if all slots are busy */
+ atomic_t slot_count; /* number of in-use slots */
+ unsigned long *bitmap; /* 0 = free slot */
+ struct page *page;
+
+ /*
+ * We keep the vma's vm_start rather than a pointer to the vma
+ * itself. The probed process or a naughty kernel module could make
+ * the vma go away, and we must handle that reasonably gracefully.
+ */
+ unsigned long vaddr; /* Page(s) of instruction slots */
+};
+
+struct uprobes_state {
+ struct xol_area *xol_area;
+ atomic_t count;
+};
+extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
+extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr, bool verify);
+extern bool __weak is_swbp_insn(uprobe_opcode_t *insn);
+extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
+extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
+extern int uprobe_mmap(struct vm_area_struct *vma);
+extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end);
+extern void uprobe_free_utask(struct task_struct *t);
+extern void uprobe_copy_process(struct task_struct *t);
+extern unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs);
+extern int uprobe_post_sstep_notifier(struct pt_regs *regs);
+extern int uprobe_pre_sstep_notifier(struct pt_regs *regs);
+extern void uprobe_notify_resume(struct pt_regs *regs);
+extern bool uprobe_deny_signal(void);
+extern bool __weak arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs);
+extern void uprobe_clear_state(struct mm_struct *mm);
+extern void uprobe_reset_state(struct mm_struct *mm);
+#else /* !CONFIG_UPROBES */
+struct uprobes_state {
+};
+static inline int
+uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+{
+ return -ENOSYS;
+}
+static inline void
+uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+{
+}
+static inline int uprobe_mmap(struct vm_area_struct *vma)
+{
+ return 0;
+}
+static inline void
+uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+}
+static inline void uprobe_notify_resume(struct pt_regs *regs)
+{
+}
+static inline bool uprobe_deny_signal(void)
+{
+ return false;
+}
+static inline unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+ return 0;
+}
+static inline void uprobe_free_utask(struct task_struct *t)
+{
+}
+static inline void uprobe_copy_process(struct task_struct *t)
+{
+}
+static inline void uprobe_clear_state(struct mm_struct *mm)
+{
+}
+static inline void uprobe_reset_state(struct mm_struct *mm)
+{
+}
+#endif /* !CONFIG_UPROBES */
+#endif /* _LINUX_UPROBES_H */
endif
obj-y := core.o ring_buffer.o callchain.o
+
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
+obj-$(CONFIG_UPROBES) += uprobes.o
+
--- /dev/null
+/*
+ * User-space Probes (UProbes)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2008-2012
+ * Authors:
+ * Srikar Dronamraju
+ * Jim Keniston
+ * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h> /* read_mapping_page */
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/rmap.h> /* anon_vma_prepare */
+#include <linux/mmu_notifier.h> /* set_pte_at_notify */
+#include <linux/swap.h> /* try_to_free_swap */
+#include <linux/ptrace.h> /* user_enable_single_step */
+#include <linux/kdebug.h> /* notifier mechanism */
+
+#include <linux/uprobes.h>
+
+#define UINSNS_PER_PAGE (PAGE_SIZE/UPROBE_XOL_SLOT_BYTES)
+#define MAX_UPROBE_XOL_SLOTS UINSNS_PER_PAGE
+
+static struct srcu_struct uprobes_srcu;
+static struct rb_root uprobes_tree = RB_ROOT;
+
+static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */
+
+#define UPROBES_HASH_SZ 13
+
+/* serialize (un)register */
+static struct mutex uprobes_mutex[UPROBES_HASH_SZ];
+
+#define uprobes_hash(v) (&uprobes_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ])
+
+/* serialize uprobe->pending_list */
+static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
+#define uprobes_mmap_hash(v) (&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ])
+
+/*
+ * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe
+ * events active at this time. Probably a fine grained per inode count is
+ * better?
+ */
+static atomic_t uprobe_events = ATOMIC_INIT(0);
+
+/*
+ * Maintain a temporary per vma info that can be used to search if a vma
+ * has already been handled. This structure is introduced since extending
+ * vm_area_struct wasnt recommended.
+ */
+struct vma_info {
+ struct list_head probe_list;
+ struct mm_struct *mm;
+ loff_t vaddr;
+};
+
+struct uprobe {
+ struct rb_node rb_node; /* node in the rb tree */
+ atomic_t ref;
+ struct rw_semaphore consumer_rwsem;
+ struct list_head pending_list;
+ struct uprobe_consumer *consumers;
+ struct inode *inode; /* Also hold a ref to inode */
+ loff_t offset;
+ int flags;
+ struct arch_uprobe arch;
+};
+
+/*
+ * valid_vma: Verify if the specified vma is an executable vma
+ * Relax restrictions while unregistering: vm_flags might have
+ * changed after breakpoint was inserted.
+ * - is_register: indicates if we are in register context.
+ * - Return 1 if the specified virtual address is in an
+ * executable vma.
+ */
+static bool valid_vma(struct vm_area_struct *vma, bool is_register)
+{
+ if (!vma->vm_file)
+ return false;
+
+ if (!is_register)
+ return true;
+
+ if ((vma->vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)) == (VM_READ|VM_EXEC))
+ return true;
+
+ return false;
+}
+
+static loff_t vma_address(struct vm_area_struct *vma, loff_t offset)
+{
+ loff_t vaddr;
+
+ vaddr = vma->vm_start + offset;
+ vaddr -= vma->vm_pgoff << PAGE_SHIFT;
+
+ return vaddr;
+}
+
+/**
+ * __replace_page - replace page in vma by new page.
+ * based on replace_page in mm/ksm.c
+ *
+ * @vma: vma that holds the pte pointing to page
+ * @page: the cowed page we are replacing by kpage
+ * @kpage: the modified page we replace page by
+ *
+ * Returns 0 on success, -EFAULT on failure.
+ */
+static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep;
+ spinlock_t *ptl;
+ unsigned long addr;
+ int err = -EFAULT;
+
+ addr = page_address_in_vma(page, vma);
+ if (addr == -EFAULT)
+ goto out;
+
+ pgd = pgd_offset(mm, addr);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_present(*pmd))
+ goto out;
+
+ ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ if (!ptep)
+ goto out;
+
+ get_page(kpage);
+ page_add_new_anon_rmap(kpage, vma, addr);
+
+ if (!PageAnon(page)) {
+ dec_mm_counter(mm, MM_FILEPAGES);
+ inc_mm_counter(mm, MM_ANONPAGES);
+ }
+
+ flush_cache_page(vma, addr, pte_pfn(*ptep));
+ ptep_clear_flush(vma, addr, ptep);
+ set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
+
+ page_remove_rmap(page);
+ if (!page_mapped(page))
+ try_to_free_swap(page);
+ put_page(page);
+ pte_unmap_unlock(ptep, ptl);
+ err = 0;
+
+out:
+ return err;
+}
+
+/**
+ * is_swbp_insn - check if instruction is breakpoint instruction.
+ * @insn: instruction to be checked.
+ * Default implementation of is_swbp_insn
+ * Returns true if @insn is a breakpoint instruction.
+ */
+bool __weak is_swbp_insn(uprobe_opcode_t *insn)
+{
+ return *insn == UPROBE_SWBP_INSN;
+}
+
+/*
+ * NOTE:
+ * Expect the breakpoint instruction to be the smallest size instruction for
+ * the architecture. If an arch has variable length instruction and the
+ * breakpoint instruction is not of the smallest length instruction
+ * supported by that architecture then we need to modify read_opcode /
+ * write_opcode accordingly. This would never be a problem for archs that
+ * have fixed length instructions.
+ */
+
+/*
+ * write_opcode - write the opcode at a given virtual address.
+ * @auprobe: arch breakpointing information.
+ * @mm: the probed process address space.
+ * @vaddr: the virtual address to store the opcode.
+ * @opcode: opcode to be written at @vaddr.
+ *
+ * Called with mm->mmap_sem held (for read and with a reference to
+ * mm).
+ *
+ * For mm @mm, write the opcode at @vaddr.
+ * Return 0 (success) or a negative errno.
+ */
+static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
+ unsigned long vaddr, uprobe_opcode_t opcode)
+{
+ struct page *old_page, *new_page;
+ struct address_space *mapping;
+ void *vaddr_old, *vaddr_new;
+ struct vm_area_struct *vma;
+ struct uprobe *uprobe;
+ loff_t addr;
+ int ret;
+
+ /* Read the page with vaddr into memory */
+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
+ if (ret <= 0)
+ return ret;
+
+ ret = -EINVAL;
+
+ /*
+ * We are interested in text pages only. Our pages of interest
+ * should be mapped for read and execute only. We desist from
+ * adding probes in write mapped pages since the breakpoints
+ * might end up in the file copy.
+ */
+ if (!valid_vma(vma, is_swbp_insn(&opcode)))
+ goto put_out;
+
+ uprobe = container_of(auprobe, struct uprobe, arch);
+ mapping = uprobe->inode->i_mapping;
+ if (mapping != vma->vm_file->f_mapping)
+ goto put_out;
+
+ addr = vma_address(vma, uprobe->offset);
+ if (vaddr != (unsigned long)addr)
+ goto put_out;
+
+ ret = -ENOMEM;
+ new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
+ if (!new_page)
+ goto put_out;
+
+ __SetPageUptodate(new_page);
+
+ /*
+ * lock page will serialize against do_wp_page()'s
+ * PageAnon() handling
+ */
+ lock_page(old_page);
+ /* copy the page now that we've got it stable */
+ vaddr_old = kmap_atomic(old_page);
+ vaddr_new = kmap_atomic(new_page);
+
+ memcpy(vaddr_new, vaddr_old, PAGE_SIZE);
+
+ /* poke the new insn in, ASSUMES we don't cross page boundary */
+ vaddr &= ~PAGE_MASK;
+ BUG_ON(vaddr + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
+ memcpy(vaddr_new + vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+
+ kunmap_atomic(vaddr_new);
+ kunmap_atomic(vaddr_old);
+
+ ret = anon_vma_prepare(vma);
+ if (ret)
+ goto unlock_out;
+
+ lock_page(new_page);
+ ret = __replace_page(vma, old_page, new_page);
+ unlock_page(new_page);
+
+unlock_out:
+ unlock_page(old_page);
+ page_cache_release(new_page);
+
+put_out:
+ put_page(old_page);
+
+ return ret;
+}
+
+/**
+ * read_opcode - read the opcode at a given virtual address.
+ * @mm: the probed process address space.
+ * @vaddr: the virtual address to read the opcode.
+ * @opcode: location to store the read opcode.
+ *
+ * Called with mm->mmap_sem held (for read and with a reference to
+ * mm.
+ *
+ * For mm @mm, read the opcode at @vaddr and store it in @opcode.
+ * Return 0 (success) or a negative errno.
+ */
+static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t *opcode)
+{
+ struct page *page;
+ void *vaddr_new;
+ int ret;
+
+ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL);
+ if (ret <= 0)
+ return ret;
+
+ lock_page(page);
+ vaddr_new = kmap_atomic(page);
+ vaddr &= ~PAGE_MASK;
+ memcpy(opcode, vaddr_new + vaddr, UPROBE_SWBP_INSN_SIZE);
+ kunmap_atomic(vaddr_new);
+ unlock_page(page);
+
+ put_page(page);
+
+ return 0;
+}
+
+static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
+{
+ uprobe_opcode_t opcode;
+ int result;
+
+ result = read_opcode(mm, vaddr, &opcode);
+ if (result)
+ return result;
+
+ if (is_swbp_insn(&opcode))
+ return 1;
+
+ return 0;
+}
+
+/**
+ * set_swbp - store breakpoint at a given address.
+ * @auprobe: arch specific probepoint information.
+ * @mm: the probed process address space.
+ * @vaddr: the virtual address to insert the opcode.
+ *
+ * For mm @mm, store the breakpoint instruction at @vaddr.
+ * Return 0 (success) or a negative errno.
+ */
+int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
+{
+ int result;
+
+ result = is_swbp_at_addr(mm, vaddr);
+ if (result == 1)
+ return -EEXIST;
+
+ if (result)
+ return result;
+
+ return write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN);
+}
+
+/**
+ * set_orig_insn - Restore the original instruction.
+ * @mm: the probed process address space.
+ * @auprobe: arch specific probepoint information.
+ * @vaddr: the virtual address to insert the opcode.
+ * @verify: if true, verify existance of breakpoint instruction.
+ *
+ * For mm @mm, restore the original opcode (opcode) at @vaddr.
+ * Return 0 (success) or a negative errno.
+ */
+int __weak
+set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, bool verify)
+{
+ if (verify) {
+ int result;
+
+ result = is_swbp_at_addr(mm, vaddr);
+ if (!result)
+ return -EINVAL;
+
+ if (result != 1)
+ return result;
+ }
+ return write_opcode(auprobe, mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
+}
+
+static int match_uprobe(struct uprobe *l, struct uprobe *r)
+{
+ if (l->inode < r->inode)
+ return -1;
+
+ if (l->inode > r->inode)
+ return 1;
+
+ if (l->offset < r->offset)
+ return -1;
+
+ if (l->offset > r->offset)
+ return 1;
+
+ return 0;
+}
+
+static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
+{
+ struct uprobe u = { .inode = inode, .offset = offset };
+ struct rb_node *n = uprobes_tree.rb_node;
+ struct uprobe *uprobe;
+ int match;
+
+ while (n) {
+ uprobe = rb_entry(n, struct uprobe, rb_node);
+ match = match_uprobe(&u, uprobe);
+ if (!match) {
+ atomic_inc(&uprobe->ref);
+ return uprobe;
+ }
+
+ if (match < 0)
+ n = n->rb_left;
+ else
+ n = n->rb_right;
+ }
+ return NULL;
+}
+
+/*
+ * Find a uprobe corresponding to a given inode:offset
+ * Acquires uprobes_treelock
+ */
+static struct uprobe *find_uprobe(struct inode *inode, loff_t offset)
+{
+ struct uprobe *uprobe;
+ unsigned long flags;
+
+ spin_lock_irqsave(&uprobes_treelock, flags);
+ uprobe = __find_uprobe(inode, offset);
+ spin_unlock_irqrestore(&uprobes_treelock, flags);
+
+ return uprobe;
+}
+
+static struct uprobe *__insert_uprobe(struct uprobe *uprobe)
+{
+ struct rb_node **p = &uprobes_tree.rb_node;
+ struct rb_node *parent = NULL;
+ struct uprobe *u;
+ int match;
+
+ while (*p) {
+ parent = *p;
+ u = rb_entry(parent, struct uprobe, rb_node);
+ match = match_uprobe(uprobe, u);
+ if (!match) {
+ atomic_inc(&u->ref);
+ return u;
+ }
+
+ if (match < 0)
+ p = &parent->rb_left;
+ else
+ p = &parent->rb_right;
+
+ }
+
+ u = NULL;
+ rb_link_node(&uprobe->rb_node, parent, p);
+ rb_insert_color(&uprobe->rb_node, &uprobes_tree);
+ /* get access + creation ref */
+ atomic_set(&uprobe->ref, 2);
+
+ return u;
+}
+
+/*
+ * Acquire uprobes_treelock.
+ * Matching uprobe already exists in rbtree;
+ * increment (access refcount) and return the matching uprobe.
+ *
+ * No matching uprobe; insert the uprobe in rb_tree;
+ * get a double refcount (access + creation) and return NULL.
+ */
+static struct uprobe *insert_uprobe(struct uprobe *uprobe)
+{
+ unsigned long flags;
+ struct uprobe *u;
+
+ spin_lock_irqsave(&uprobes_treelock, flags);
+ u = __insert_uprobe(uprobe);
+ spin_unlock_irqrestore(&uprobes_treelock, flags);
+
+ /* For now assume that the instruction need not be single-stepped */
+ uprobe->flags |= UPROBE_SKIP_SSTEP;
+
+ return u;
+}
+
+static void put_uprobe(struct uprobe *uprobe)
+{
+ if (atomic_dec_and_test(&uprobe->ref))
+ kfree(uprobe);
+}
+
+static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
+{
+ struct uprobe *uprobe, *cur_uprobe;
+
+ uprobe = kzalloc(sizeof(struct uprobe), GFP_KERNEL);
+ if (!uprobe)
+ return NULL;
+
+ uprobe->inode = igrab(inode);
+ uprobe->offset = offset;
+ init_rwsem(&uprobe->consumer_rwsem);
+ INIT_LIST_HEAD(&uprobe->pending_list);
+
+ /* add to uprobes_tree, sorted on inode:offset */
+ cur_uprobe = insert_uprobe(uprobe);
+
+ /* a uprobe exists for this inode:offset combination */
+ if (cur_uprobe) {
+ kfree(uprobe);
+ uprobe = cur_uprobe;
+ iput(inode);
+ } else {
+ atomic_inc(&uprobe_events);
+ }
+
+ return uprobe;
+}
+
+static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
+{
+ struct uprobe_consumer *uc;
+
+ if (!(uprobe->flags & UPROBE_RUN_HANDLER))
+ return;
+
+ down_read(&uprobe->consumer_rwsem);
+ for (uc = uprobe->consumers; uc; uc = uc->next) {
+ if (!uc->filter || uc->filter(uc, current))
+ uc->handler(uc, regs);
+ }
+ up_read(&uprobe->consumer_rwsem);
+}
+
+/* Returns the previous consumer */
+static struct uprobe_consumer *
+consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc)
+{
+ down_write(&uprobe->consumer_rwsem);
+ uc->next = uprobe->consumers;
+ uprobe->consumers = uc;
+ up_write(&uprobe->consumer_rwsem);
+
+ return uc->next;
+}
+
+/*
+ * For uprobe @uprobe, delete the consumer @uc.
+ * Return true if the @uc is deleted successfully
+ * or return false.
+ */
+static bool consumer_del(struct uprobe *uprobe, struct uprobe_consumer *uc)
+{
+ struct uprobe_consumer **con;
+ bool ret = false;
+
+ down_write(&uprobe->consumer_rwsem);
+ for (con = &uprobe->consumers; *con; con = &(*con)->next) {
+ if (*con == uc) {
+ *con = uc->next;
+ ret = true;
+ break;
+ }
+ }
+ up_write(&uprobe->consumer_rwsem);
+
+ return ret;
+}
+
+static int
+__copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *insn,
+ unsigned long nbytes, unsigned long offset)
+{
+ struct file *filp = vma->vm_file;
+ struct page *page;
+ void *vaddr;
+ unsigned long off1;
+ unsigned long idx;
+
+ if (!filp)
+ return -EINVAL;
+
+ idx = (unsigned long)(offset >> PAGE_CACHE_SHIFT);
+ off1 = offset &= ~PAGE_MASK;
+
+ /*
+ * Ensure that the page that has the original instruction is
+ * populated and in page-cache.
+ */
+ page = read_mapping_page(mapping, idx, filp);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ vaddr = kmap_atomic(page);
+ memcpy(insn, vaddr + off1, nbytes);
+ kunmap_atomic(vaddr);
+ page_cache_release(page);
+
+ return 0;
+}
+
+static int
+copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr)
+{
+ struct address_space *mapping;
+ unsigned long nbytes;
+ int bytes;
+
+ addr &= ~PAGE_MASK;
+ nbytes = PAGE_SIZE - addr;
+ mapping = uprobe->inode->i_mapping;
+
+ /* Instruction at end of binary; copy only available bytes */
+ if (uprobe->offset + MAX_UINSN_BYTES > uprobe->inode->i_size)
+ bytes = uprobe->inode->i_size - uprobe->offset;
+ else
+ bytes = MAX_UINSN_BYTES;
+
+ /* Instruction at the page-boundary; copy bytes in second page */
+ if (nbytes < bytes) {
+ if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes,
+ bytes - nbytes, uprobe->offset + nbytes))
+ return -ENOMEM;
+
+ bytes = nbytes;
+ }
+ return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset);
+}
+
+/*
+ * How mm->uprobes_state.count gets updated
+ * uprobe_mmap() increments the count if
+ * - it successfully adds a breakpoint.
+ * - it cannot add a breakpoint, but sees that there is a underlying
+ * breakpoint (via a is_swbp_at_addr()).
+ *
+ * uprobe_munmap() decrements the count if
+ * - it sees a underlying breakpoint, (via is_swbp_at_addr)
+ * (Subsequent uprobe_unregister wouldnt find the breakpoint
+ * unless a uprobe_mmap kicks in, since the old vma would be
+ * dropped just after uprobe_munmap.)
+ *
+ * uprobe_register increments the count if:
+ * - it successfully adds a breakpoint.
+ *
+ * uprobe_unregister decrements the count if:
+ * - it sees a underlying breakpoint and removes successfully.
+ * (via is_swbp_at_addr)
+ * (Subsequent uprobe_munmap wouldnt find the breakpoint
+ * since there is no underlying breakpoint after the
+ * breakpoint removal.)
+ */
+static int
+install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
+ struct vm_area_struct *vma, loff_t vaddr)
+{
+ unsigned long addr;
+ int ret;
+
+ /*
+ * If probe is being deleted, unregister thread could be done with
+ * the vma-rmap-walk through. Adding a probe now can be fatal since
+ * nobody will be able to cleanup. Also we could be from fork or
+ * mremap path, where the probe might have already been inserted.
+ * Hence behave as if probe already existed.
+ */
+ if (!uprobe->consumers)
+ return -EEXIST;
+
+ addr = (unsigned long)vaddr;
+
+ if (!(uprobe->flags & UPROBE_COPY_INSN)) {
+ ret = copy_insn(uprobe, vma, addr);
+ if (ret)
+ return ret;
+
+ if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
+ return -EEXIST;
+
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm);
+ if (ret)
+ return ret;
+
+ uprobe->flags |= UPROBE_COPY_INSN;
+ }
+
+ /*
+ * Ideally, should be updating the probe count after the breakpoint
+ * has been successfully inserted. However a thread could hit the
+ * breakpoint we just inserted even before the probe count is
+ * incremented. If this is the first breakpoint placed, breakpoint
+ * notifier might ignore uprobes and pass the trap to the thread.
+ * Hence increment before and decrement on failure.
+ */
+ atomic_inc(&mm->uprobes_state.count);
+ ret = set_swbp(&uprobe->arch, mm, addr);
+ if (ret)
+ atomic_dec(&mm->uprobes_state.count);
+
+ return ret;
+}
+
+static void
+remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, loff_t vaddr)
+{
+ if (!set_orig_insn(&uprobe->arch, mm, (unsigned long)vaddr, true))
+ atomic_dec(&mm->uprobes_state.count);
+}
+
+/*
+ * There could be threads that have hit the breakpoint and are entering the
+ * notifier code and trying to acquire the uprobes_treelock. The thread
+ * calling delete_uprobe() that is removing the uprobe from the rb_tree can
+ * race with these threads and might acquire the uprobes_treelock compared
+ * to some of the breakpoint hit threads. In such a case, the breakpoint
+ * hit threads will not find the uprobe. The current unregistering thread
+ * waits till all other threads have hit a breakpoint, to acquire the
+ * uprobes_treelock before the uprobe is removed from the rbtree.
+ */
+static void delete_uprobe(struct uprobe *uprobe)
+{
+ unsigned long flags;
+
+ synchronize_srcu(&uprobes_srcu);
+ spin_lock_irqsave(&uprobes_treelock, flags);
+ rb_erase(&uprobe->rb_node, &uprobes_tree);
+ spin_unlock_irqrestore(&uprobes_treelock, flags);
+ iput(uprobe->inode);
+ put_uprobe(uprobe);
+ atomic_dec(&uprobe_events);
+}
+
+static struct vma_info *
+__find_next_vma_info(struct address_space *mapping, struct list_head *head,
+ struct vma_info *vi, loff_t offset, bool is_register)
+{
+ struct prio_tree_iter iter;
+ struct vm_area_struct *vma;
+ struct vma_info *tmpvi;
+ unsigned long pgoff;
+ int existing_vma;
+ loff_t vaddr;
+
+ pgoff = offset >> PAGE_SHIFT;
+
+ vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ if (!valid_vma(vma, is_register))
+ continue;
+
+ existing_vma = 0;
+ vaddr = vma_address(vma, offset);
+
+ list_for_each_entry(tmpvi, head, probe_list) {
+ if (tmpvi->mm == vma->vm_mm && tmpvi->vaddr == vaddr) {
+ existing_vma = 1;
+ break;
+ }
+ }
+
+ /*
+ * Another vma needs a probe to be installed. However skip
+ * installing the probe if the vma is about to be unlinked.
+ */
+ if (!existing_vma && atomic_inc_not_zero(&vma->vm_mm->mm_users)) {
+ vi->mm = vma->vm_mm;
+ vi->vaddr = vaddr;
+ list_add(&vi->probe_list, head);
+
+ return vi;
+ }
+ }
+
+ return NULL;
+}
+
+/*
+ * Iterate in the rmap prio tree and find a vma where a probe has not
+ * yet been inserted.
+ */
+static struct vma_info *
+find_next_vma_info(struct address_space *mapping, struct list_head *head,
+ loff_t offset, bool is_register)
+{
+ struct vma_info *vi, *retvi;
+
+ vi = kzalloc(sizeof(struct vma_info), GFP_KERNEL);
+ if (!vi)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&mapping->i_mmap_mutex);
+ retvi = __find_next_vma_info(mapping, head, vi, offset, is_register);
+ mutex_unlock(&mapping->i_mmap_mutex);
+
+ if (!retvi)
+ kfree(vi);
+
+ return retvi;
+}
+
+static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
+{
+ struct list_head try_list;
+ struct vm_area_struct *vma;
+ struct address_space *mapping;
+ struct vma_info *vi, *tmpvi;
+ struct mm_struct *mm;
+ loff_t vaddr;
+ int ret;
+
+ mapping = uprobe->inode->i_mapping;
+ INIT_LIST_HEAD(&try_list);
+
+ ret = 0;
+
+ for (;;) {
+ vi = find_next_vma_info(mapping, &try_list, uprobe->offset, is_register);
+ if (!vi)
+ break;
+
+ if (IS_ERR(vi)) {
+ ret = PTR_ERR(vi);
+ break;
+ }
+
+ mm = vi->mm;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, (unsigned long)vi->vaddr);
+ if (!vma || !valid_vma(vma, is_register)) {
+ list_del(&vi->probe_list);
+ kfree(vi);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ continue;
+ }
+ vaddr = vma_address(vma, uprobe->offset);
+ if (vma->vm_file->f_mapping->host != uprobe->inode ||
+ vaddr != vi->vaddr) {
+ list_del(&vi->probe_list);
+ kfree(vi);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ continue;
+ }
+
+ if (is_register)
+ ret = install_breakpoint(uprobe, mm, vma, vi->vaddr);
+ else
+ remove_breakpoint(uprobe, mm, vi->vaddr);
+
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ if (is_register) {
+ if (ret && ret == -EEXIST)
+ ret = 0;
+ if (ret)
+ break;
+ }
+ }
+
+ list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) {
+ list_del(&vi->probe_list);
+ kfree(vi);
+ }
+
+ return ret;
+}
+
+static int __uprobe_register(struct uprobe *uprobe)
+{
+ return register_for_each_vma(uprobe, true);
+}
+
+static void __uprobe_unregister(struct uprobe *uprobe)
+{
+ if (!register_for_each_vma(uprobe, false))
+ delete_uprobe(uprobe);
+
+ /* TODO : cant unregister? schedule a worker thread */
+}
+
+/*
+ * uprobe_register - register a probe
+ * @inode: the file in which the probe has to be placed.
+ * @offset: offset from the start of the file.
+ * @uc: information on howto handle the probe..
+ *
+ * Apart from the access refcount, uprobe_register() takes a creation
+ * refcount (thro alloc_uprobe) if and only if this @uprobe is getting
+ * inserted into the rbtree (i.e first consumer for a @inode:@offset
+ * tuple). Creation refcount stops uprobe_unregister from freeing the
+ * @uprobe even before the register operation is complete. Creation
+ * refcount is released when the last @uc for the @uprobe
+ * unregisters.
+ *
+ * Return errno if it cannot successully install probes
+ * else return 0 (success)
+ */
+int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+{
+ struct uprobe *uprobe;
+ int ret;
+
+ if (!inode || !uc || uc->next)
+ return -EINVAL;
+
+ if (offset > i_size_read(inode))
+ return -EINVAL;
+
+ ret = 0;
+ mutex_lock(uprobes_hash(inode));
+ uprobe = alloc_uprobe(inode, offset);
+
+ if (uprobe && !consumer_add(uprobe, uc)) {
+ ret = __uprobe_register(uprobe);
+ if (ret) {
+ uprobe->consumers = NULL;
+ __uprobe_unregister(uprobe);
+ } else {
+ uprobe->flags |= UPROBE_RUN_HANDLER;
+ }
+ }
+
+ mutex_unlock(uprobes_hash(inode));
+ put_uprobe(uprobe);
+
+ return ret;
+}
+
+/*
+ * uprobe_unregister - unregister a already registered probe.
+ * @inode: the file in which the probe has to be removed.
+ * @offset: offset from the start of the file.
+ * @uc: identify which probe if multiple probes are colocated.
+ */
+void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc)
+{
+ struct uprobe *uprobe;
+
+ if (!inode || !uc)
+ return;
+
+ uprobe = find_uprobe(inode, offset);
+ if (!uprobe)
+ return;
+
+ mutex_lock(uprobes_hash(inode));
+
+ if (consumer_del(uprobe, uc)) {
+ if (!uprobe->consumers) {
+ __uprobe_unregister(uprobe);
+ uprobe->flags &= ~UPROBE_RUN_HANDLER;
+ }
+ }
+
+ mutex_unlock(uprobes_hash(inode));
+ if (uprobe)
+ put_uprobe(uprobe);
+}
+
+/*
+ * Of all the nodes that correspond to the given inode, return the node
+ * with the least offset.
+ */
+static struct rb_node *find_least_offset_node(struct inode *inode)
+{
+ struct uprobe u = { .inode = inode, .offset = 0};
+ struct rb_node *n = uprobes_tree.rb_node;
+ struct rb_node *close_node = NULL;
+ struct uprobe *uprobe;
+ int match;
+
+ while (n) {
+ uprobe = rb_entry(n, struct uprobe, rb_node);
+ match = match_uprobe(&u, uprobe);
+
+ if (uprobe->inode == inode)
+ close_node = n;
+
+ if (!match)
+ return close_node;
+
+ if (match < 0)
+ n = n->rb_left;
+ else
+ n = n->rb_right;
+ }
+
+ return close_node;
+}
+
+/*
+ * For a given inode, build a list of probes that need to be inserted.
+ */
+static void build_probe_list(struct inode *inode, struct list_head *head)
+{
+ struct uprobe *uprobe;
+ unsigned long flags;
+ struct rb_node *n;
+
+ spin_lock_irqsave(&uprobes_treelock, flags);
+
+ n = find_least_offset_node(inode);
+
+ for (; n; n = rb_next(n)) {
+ uprobe = rb_entry(n, struct uprobe, rb_node);
+ if (uprobe->inode != inode)
+ break;
+
+ list_add(&uprobe->pending_list, head);
+ atomic_inc(&uprobe->ref);
+ }
+
+ spin_unlock_irqrestore(&uprobes_treelock, flags);
+}
+
+/*
+ * Called from mmap_region.
+ * called with mm->mmap_sem acquired.
+ *
+ * Return -ve no if we fail to insert probes and we cannot
+ * bail-out.
+ * Return 0 otherwise. i.e:
+ *
+ * - successful insertion of probes
+ * - (or) no possible probes to be inserted.
+ * - (or) insertion of probes failed but we can bail-out.
+ */
+int uprobe_mmap(struct vm_area_struct *vma)
+{
+ struct list_head tmp_list;
+ struct uprobe *uprobe, *u;
+ struct inode *inode;
+ int ret, count;
+
+ if (!atomic_read(&uprobe_events) || !valid_vma(vma, true))
+ return 0;
+
+ inode = vma->vm_file->f_mapping->host;
+ if (!inode)
+ return 0;
+
+ INIT_LIST_HEAD(&tmp_list);
+ mutex_lock(uprobes_mmap_hash(inode));
+ build_probe_list(inode, &tmp_list);
+
+ ret = 0;
+ count = 0;
+
+ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
+ loff_t vaddr;
+
+ list_del(&uprobe->pending_list);
+ if (!ret) {
+ vaddr = vma_address(vma, uprobe->offset);
+
+ if (vaddr < vma->vm_start || vaddr >= vma->vm_end) {
+ put_uprobe(uprobe);
+ continue;
+ }
+
+ ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
+
+ /* Ignore double add: */
+ if (ret == -EEXIST) {
+ ret = 0;
+
+ if (!is_swbp_at_addr(vma->vm_mm, vaddr))
+ continue;
+
+ /*
+ * Unable to insert a breakpoint, but
+ * breakpoint lies underneath. Increment the
+ * probe count.
+ */
+ atomic_inc(&vma->vm_mm->uprobes_state.count);
+ }
+
+ if (!ret)
+ count++;
+ }
+ put_uprobe(uprobe);
+ }
+
+ mutex_unlock(uprobes_mmap_hash(inode));
+
+ if (ret)
+ atomic_sub(count, &vma->vm_mm->uprobes_state.count);
+
+ return ret;
+}
+
+/*
+ * Called in context of a munmap of a vma.
+ */
+void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
+{
+ struct list_head tmp_list;
+ struct uprobe *uprobe, *u;
+ struct inode *inode;
+
+ if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
+ return;
+
+ if (!atomic_read(&vma->vm_mm->uprobes_state.count))
+ return;
+
+ inode = vma->vm_file->f_mapping->host;
+ if (!inode)
+ return;
+
+ INIT_LIST_HEAD(&tmp_list);
+ mutex_lock(uprobes_mmap_hash(inode));
+ build_probe_list(inode, &tmp_list);
+
+ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
+ loff_t vaddr;
+
+ list_del(&uprobe->pending_list);
+ vaddr = vma_address(vma, uprobe->offset);
+
+ if (vaddr >= start && vaddr < end) {
+ /*
+ * An unregister could have removed the probe before
+ * unmap. So check before we decrement the count.
+ */
+ if (is_swbp_at_addr(vma->vm_mm, vaddr) == 1)
+ atomic_dec(&vma->vm_mm->uprobes_state.count);
+ }
+ put_uprobe(uprobe);
+ }
+ mutex_unlock(uprobes_mmap_hash(inode));
+}
+
+/* Slot allocation for XOL */
+static int xol_add_vma(struct xol_area *area)
+{
+ struct mm_struct *mm;
+ int ret;
+
+ area->page = alloc_page(GFP_HIGHUSER);
+ if (!area->page)
+ return -ENOMEM;
+
+ ret = -EALREADY;
+ mm = current->mm;
+
+ down_write(&mm->mmap_sem);
+ if (mm->uprobes_state.xol_area)
+ goto fail;
+
+ ret = -ENOMEM;
+
+ /* Try to map as high as possible, this is only a hint. */
+ area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE, PAGE_SIZE, 0, 0);
+ if (area->vaddr & ~PAGE_MASK) {
+ ret = area->vaddr;
+ goto fail;
+ }
+
+ ret = install_special_mapping(mm, area->vaddr, PAGE_SIZE,
+ VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO, &area->page);
+ if (ret)
+ goto fail;
+
+ smp_wmb(); /* pairs with get_xol_area() */
+ mm->uprobes_state.xol_area = area;
+ ret = 0;
+
+fail:
+ up_write(&mm->mmap_sem);
+ if (ret)
+ __free_page(area->page);
+
+ return ret;
+}
+
+static struct xol_area *get_xol_area(struct mm_struct *mm)
+{
+ struct xol_area *area;
+
+ area = mm->uprobes_state.xol_area;
+ smp_read_barrier_depends(); /* pairs with wmb in xol_add_vma() */
+
+ return area;
+}
+
+/*
+ * xol_alloc_area - Allocate process's xol_area.
+ * This area will be used for storing instructions for execution out of
+ * line.
+ *
+ * Returns the allocated area or NULL.
+ */
+static struct xol_area *xol_alloc_area(void)
+{
+ struct xol_area *area;
+
+ area = kzalloc(sizeof(*area), GFP_KERNEL);
+ if (unlikely(!area))
+ return NULL;
+
+ area->bitmap = kzalloc(BITS_TO_LONGS(UINSNS_PER_PAGE) * sizeof(long), GFP_KERNEL);
+
+ if (!area->bitmap)
+ goto fail;
+
+ init_waitqueue_head(&area->wq);
+ if (!xol_add_vma(area))
+ return area;
+
+fail:
+ kfree(area->bitmap);
+ kfree(area);
+
+ return get_xol_area(current->mm);
+}
+
+/*
+ * uprobe_clear_state - Free the area allocated for slots.
+ */
+void uprobe_clear_state(struct mm_struct *mm)
+{
+ struct xol_area *area = mm->uprobes_state.xol_area;
+
+ if (!area)
+ return;
+
+ put_page(area->page);
+ kfree(area->bitmap);
+ kfree(area);
+}
+
+/*
+ * uprobe_reset_state - Free the area allocated for slots.
+ */
+void uprobe_reset_state(struct mm_struct *mm)
+{
+ mm->uprobes_state.xol_area = NULL;
+ atomic_set(&mm->uprobes_state.count, 0);
+}
+
+/*
+ * - search for a free slot.
+ */
+static unsigned long xol_take_insn_slot(struct xol_area *area)
+{
+ unsigned long slot_addr;
+ int slot_nr;
+
+ do {
+ slot_nr = find_first_zero_bit(area->bitmap, UINSNS_PER_PAGE);
+ if (slot_nr < UINSNS_PER_PAGE) {
+ if (!test_and_set_bit(slot_nr, area->bitmap))
+ break;
+
+ slot_nr = UINSNS_PER_PAGE;
+ continue;
+ }
+ wait_event(area->wq, (atomic_read(&area->slot_count) < UINSNS_PER_PAGE));
+ } while (slot_nr >= UINSNS_PER_PAGE);
+
+ slot_addr = area->vaddr + (slot_nr * UPROBE_XOL_SLOT_BYTES);
+ atomic_inc(&area->slot_count);
+
+ return slot_addr;
+}
+
+/*
+ * xol_get_insn_slot - If was not allocated a slot, then
+ * allocate a slot.
+ * Returns the allocated slot address or 0.
+ */
+static unsigned long xol_get_insn_slot(struct uprobe *uprobe, unsigned long slot_addr)
+{
+ struct xol_area *area;
+ unsigned long offset;
+ void *vaddr;
+
+ area = get_xol_area(current->mm);
+ if (!area) {
+ area = xol_alloc_area();
+ if (!area)
+ return 0;
+ }
+ current->utask->xol_vaddr = xol_take_insn_slot(area);
+
+ /*
+ * Initialize the slot if xol_vaddr points to valid
+ * instruction slot.
+ */
+ if (unlikely(!current->utask->xol_vaddr))
+ return 0;
+
+ current->utask->vaddr = slot_addr;
+ offset = current->utask->xol_vaddr & ~PAGE_MASK;
+ vaddr = kmap_atomic(area->page);
+ memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES);
+ kunmap_atomic(vaddr);
+
+ return current->utask->xol_vaddr;
+}
+
+/*
+ * xol_free_insn_slot - If slot was earlier allocated by
+ * @xol_get_insn_slot(), make the slot available for
+ * subsequent requests.
+ */
+static void xol_free_insn_slot(struct task_struct *tsk)
+{
+ struct xol_area *area;
+ unsigned long vma_end;
+ unsigned long slot_addr;
+
+ if (!tsk->mm || !tsk->mm->uprobes_state.xol_area || !tsk->utask)
+ return;
+
+ slot_addr = tsk->utask->xol_vaddr;
+
+ if (unlikely(!slot_addr || IS_ERR_VALUE(slot_addr)))
+ return;
+
+ area = tsk->mm->uprobes_state.xol_area;
+ vma_end = area->vaddr + PAGE_SIZE;
+ if (area->vaddr <= slot_addr && slot_addr < vma_end) {
+ unsigned long offset;
+ int slot_nr;
+
+ offset = slot_addr - area->vaddr;
+ slot_nr = offset / UPROBE_XOL_SLOT_BYTES;
+ if (slot_nr >= UINSNS_PER_PAGE)
+ return;
+
+ clear_bit(slot_nr, area->bitmap);
+ atomic_dec(&area->slot_count);
+ if (waitqueue_active(&area->wq))
+ wake_up(&area->wq);
+
+ tsk->utask->xol_vaddr = 0;
+ }
+}
+
+/**
+ * uprobe_get_swbp_addr - compute address of swbp given post-swbp regs
+ * @regs: Reflects the saved state of the task after it has hit a breakpoint
+ * instruction.
+ * Return the address of the breakpoint instruction.
+ */
+unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+ return instruction_pointer(regs) - UPROBE_SWBP_INSN_SIZE;
+}
+
+/*
+ * Called with no locks held.
+ * Called in context of a exiting or a exec-ing thread.
+ */
+void uprobe_free_utask(struct task_struct *t)
+{
+ struct uprobe_task *utask = t->utask;
+
+ if (t->uprobe_srcu_id != -1)
+ srcu_read_unlock_raw(&uprobes_srcu, t->uprobe_srcu_id);
+
+ if (!utask)
+ return;
+
+ if (utask->active_uprobe)
+ put_uprobe(utask->active_uprobe);
+
+ xol_free_insn_slot(t);
+ kfree(utask);
+ t->utask = NULL;
+}
+
+/*
+ * Called in context of a new clone/fork from copy_process.
+ */
+void uprobe_copy_process(struct task_struct *t)
+{
+ t->utask = NULL;
+ t->uprobe_srcu_id = -1;
+}
+
+/*
+ * Allocate a uprobe_task object for the task.
+ * Called when the thread hits a breakpoint for the first time.
+ *
+ * Returns:
+ * - pointer to new uprobe_task on success
+ * - NULL otherwise
+ */
+static struct uprobe_task *add_utask(void)
+{
+ struct uprobe_task *utask;
+
+ utask = kzalloc(sizeof *utask, GFP_KERNEL);
+ if (unlikely(!utask))
+ return NULL;
+
+ utask->active_uprobe = NULL;
+ current->utask = utask;
+ return utask;
+}
+
+/* Prepare to single-step probed instruction out of line. */
+static int
+pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long vaddr)
+{
+ if (xol_get_insn_slot(uprobe, vaddr) && !arch_uprobe_pre_xol(&uprobe->arch, regs))
+ return 0;
+
+ return -EFAULT;
+}
+
+/*
+ * If we are singlestepping, then ensure this thread is not connected to
+ * non-fatal signals until completion of singlestep. When xol insn itself
+ * triggers the signal, restart the original insn even if the task is
+ * already SIGKILL'ed (since coredump should report the correct ip). This
+ * is even more important if the task has a handler for SIGSEGV/etc, The
+ * _same_ instruction should be repeated again after return from the signal
+ * handler, and SSTEP can never finish in this case.
+ */
+bool uprobe_deny_signal(void)
+{
+ struct task_struct *t = current;
+ struct uprobe_task *utask = t->utask;
+
+ if (likely(!utask || !utask->active_uprobe))
+ return false;
+
+ WARN_ON_ONCE(utask->state != UTASK_SSTEP);
+
+ if (signal_pending(t)) {
+ spin_lock_irq(&t->sighand->siglock);
+ clear_tsk_thread_flag(t, TIF_SIGPENDING);
+ spin_unlock_irq(&t->sighand->siglock);
+
+ if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {
+ utask->state = UTASK_SSTEP_TRAPPED;
+ set_tsk_thread_flag(t, TIF_UPROBE);
+ set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+ }
+ }
+
+ return true;
+}
+
+/*
+ * Avoid singlestepping the original instruction if the original instruction
+ * is a NOP or can be emulated.
+ */
+static bool can_skip_sstep(struct uprobe *uprobe, struct pt_regs *regs)
+{
+ if (arch_uprobe_skip_sstep(&uprobe->arch, regs))
+ return true;
+
+ uprobe->flags &= ~UPROBE_SKIP_SSTEP;
+ return false;
+}
+
+/*
+ * Run handler and ask thread to singlestep.
+ * Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
+ */
+static void handle_swbp(struct pt_regs *regs)
+{
+ struct vm_area_struct *vma;
+ struct uprobe_task *utask;
+ struct uprobe *uprobe;
+ struct mm_struct *mm;
+ unsigned long bp_vaddr;
+
+ uprobe = NULL;
+ bp_vaddr = uprobe_get_swbp_addr(regs);
+ mm = current->mm;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, bp_vaddr);
+
+ if (vma && vma->vm_start <= bp_vaddr && valid_vma(vma, false)) {
+ struct inode *inode;
+ loff_t offset;
+
+ inode = vma->vm_file->f_mapping->host;
+ offset = bp_vaddr - vma->vm_start;
+ offset += (vma->vm_pgoff << PAGE_SHIFT);
+ uprobe = find_uprobe(inode, offset);
+ }
+
+ srcu_read_unlock_raw(&uprobes_srcu, current->uprobe_srcu_id);
+ current->uprobe_srcu_id = -1;
+ up_read(&mm->mmap_sem);
+
+ if (!uprobe) {
+ /* No matching uprobe; signal SIGTRAP. */
+ send_sig(SIGTRAP, current, 0);
+ return;
+ }
+
+ utask = current->utask;
+ if (!utask) {
+ utask = add_utask();
+ /* Cannot allocate; re-execute the instruction. */
+ if (!utask)
+ goto cleanup_ret;
+ }
+ utask->active_uprobe = uprobe;
+ handler_chain(uprobe, regs);
+ if (uprobe->flags & UPROBE_SKIP_SSTEP && can_skip_sstep(uprobe, regs))
+ goto cleanup_ret;
+
+ utask->state = UTASK_SSTEP;
+ if (!pre_ssout(uprobe, regs, bp_vaddr)) {
+ user_enable_single_step(current);
+ return;
+ }
+
+cleanup_ret:
+ if (utask) {
+ utask->active_uprobe = NULL;
+ utask->state = UTASK_RUNNING;
+ }
+ if (uprobe) {
+ if (!(uprobe->flags & UPROBE_SKIP_SSTEP))
+
+ /*
+ * cannot singlestep; cannot skip instruction;
+ * re-execute the instruction.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+
+ put_uprobe(uprobe);
+ }
+}
+
+/*
+ * Perform required fix-ups and disable singlestep.
+ * Allow pending signals to take effect.
+ */
+static void handle_singlestep(struct uprobe_task *utask, struct pt_regs *regs)
+{
+ struct uprobe *uprobe;
+
+ uprobe = utask->active_uprobe;
+ if (utask->state == UTASK_SSTEP_ACK)
+ arch_uprobe_post_xol(&uprobe->arch, regs);
+ else if (utask->state == UTASK_SSTEP_TRAPPED)
+ arch_uprobe_abort_xol(&uprobe->arch, regs);
+ else
+ WARN_ON_ONCE(1);
+
+ put_uprobe(uprobe);
+ utask->active_uprobe = NULL;
+ utask->state = UTASK_RUNNING;
+ user_disable_single_step(current);
+ xol_free_insn_slot(current);
+
+ spin_lock_irq(¤t->sighand->siglock);
+ recalc_sigpending(); /* see uprobe_deny_signal() */
+ spin_unlock_irq(¤t->sighand->siglock);
+}
+
+/*
+ * On breakpoint hit, breakpoint notifier sets the TIF_UPROBE flag. (and on
+ * subsequent probe hits on the thread sets the state to UTASK_BP_HIT) and
+ * allows the thread to return from interrupt.
+ *
+ * On singlestep exception, singlestep notifier sets the TIF_UPROBE flag and
+ * also sets the state to UTASK_SSTEP_ACK and allows the thread to return from
+ * interrupt.
+ *
+ * While returning to userspace, thread notices the TIF_UPROBE flag and calls
+ * uprobe_notify_resume().
+ */
+void uprobe_notify_resume(struct pt_regs *regs)
+{
+ struct uprobe_task *utask;
+
+ utask = current->utask;
+ if (!utask || utask->state == UTASK_BP_HIT)
+ handle_swbp(regs);
+ else
+ handle_singlestep(utask, regs);
+}
+
+/*
+ * uprobe_pre_sstep_notifier gets called from interrupt context as part of
+ * notifier mechanism. Set TIF_UPROBE flag and indicate breakpoint hit.
+ */
+int uprobe_pre_sstep_notifier(struct pt_regs *regs)
+{
+ struct uprobe_task *utask;
+
+ if (!current->mm || !atomic_read(¤t->mm->uprobes_state.count))
+ /* task is currently not uprobed */
+ return 0;
+
+ utask = current->utask;
+ if (utask)
+ utask->state = UTASK_BP_HIT;
+
+ set_thread_flag(TIF_UPROBE);
+ current->uprobe_srcu_id = srcu_read_lock_raw(&uprobes_srcu);
+
+ return 1;
+}
+
+/*
+ * uprobe_post_sstep_notifier gets called in interrupt context as part of notifier
+ * mechanism. Set TIF_UPROBE flag and indicate completion of singlestep.
+ */
+int uprobe_post_sstep_notifier(struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ if (!current->mm || !utask || !utask->active_uprobe)
+ /* task is currently not uprobed */
+ return 0;
+
+ utask->state = UTASK_SSTEP_ACK;
+ set_thread_flag(TIF_UPROBE);
+ return 1;
+}
+
+static struct notifier_block uprobe_exception_nb = {
+ .notifier_call = arch_uprobe_exception_notify,
+ .priority = INT_MAX-1, /* notified after kprobes, kgdb */
+};
+
+static int __init init_uprobes(void)
+{
+ int i;
+
+ for (i = 0; i < UPROBES_HASH_SZ; i++) {
+ mutex_init(&uprobes_mutex[i]);
+ mutex_init(&uprobes_mmap_mutex[i]);
+ }
+ init_srcu_struct(&uprobes_srcu);
+
+ return register_die_notifier(&uprobe_exception_nb);
+}
+module_init(init_uprobes);
+
+static void __exit exit_uprobes(void)
+{
+}
+module_exit(exit_uprobes);
#include <linux/oom.h>
#include <linux/khugepaged.h>
#include <linux/signalfd.h>
+#include <linux/uprobes.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
if (retval)
goto out;
+
+ if (file && uprobe_mmap(tmp))
+ goto out;
}
/* a new mm has just been created */
arch_dup_mmap(oldmm, mm);
might_sleep();
if (atomic_dec_and_test(&mm->mm_users)) {
+ uprobe_clear_state(mm);
exit_aio(mm);
ksm_exit(mm);
khugepaged_exit(mm); /* must run before exit_mmap */
exit_pi_state_list(tsk);
#endif
+ uprobe_free_utask(tsk);
+
/* Get rid of any cached register state */
deactivate_mm(tsk, mm);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
mm->pmd_huge_pte = NULL;
#endif
+ uprobe_reset_state(mm);
if (!mm_init(mm, tsk))
goto fail_nomem;
INIT_LIST_HEAD(&p->pi_state_list);
p->pi_state_cache = NULL;
#endif
+ uprobe_copy_process(p);
/*
* sigaltstack should be cleared when sharing the same VM
*/
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
#include <linux/user_namespace.h>
+#include <linux/uprobes.h>
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
struct signal_struct *signal = current->signal;
int signr;
+ if (unlikely(uprobe_deny_signal()))
+ return 0;
+
relock:
/*
* We'll jump back here after any time we were stopped in TASK_STOPPED.
depends on HAVE_REGS_AND_STACK_ACCESS_API
bool "Enable kprobes-based dynamic events"
select TRACING
+ select PROBE_EVENTS
default y
help
This allows the user to add tracing events (similar to tracepoints)
This option is also required by perf-probe subcommand of perf tools.
If you want to use perf tools, this option is strongly recommended.
+config UPROBE_EVENT
+ bool "Enable uprobes-based dynamic events"
+ depends on ARCH_SUPPORTS_UPROBES
+ depends on MMU
+ select UPROBES
+ select PROBE_EVENTS
+ select TRACING
+ default n
+ help
+ This allows the user to add tracing events on top of userspace
+ dynamic events (similar to tracepoints) on the fly via the trace
+ events interface. Those events can be inserted wherever uprobes
+ can probe, and record various registers.
+ This option is required if you plan to use perf-probe subcommand
+ of perf tools on user space applications.
+
+config PROBE_EVENTS
+ def_bool n
+
config DYNAMIC_FTRACE
bool "enable/disable ftrace tracepoints dynamically"
depends on FUNCTION_TRACER
ifeq ($(CONFIG_TRACING),y)
obj-$(CONFIG_KGDB_KDB) += trace_kdb.o
endif
+obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o
+obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o
libftrace-y := ftrace.o
unsigned long ret_ip;
};
+struct uprobe_trace_entry_head {
+ struct trace_entry ent;
+ unsigned long ip;
+};
+
/*
* trace_flag_type is an enumeration that holds different
* states when a trace occurs. These are:
#include <linux/module.h>
#include <linux/uaccess.h>
-#include <linux/kprobes.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include <linux/smp.h>
-#include <linux/debugfs.h>
-#include <linux/types.h>
-#include <linux/string.h>
-#include <linux/ctype.h>
-#include <linux/ptrace.h>
-#include <linux/perf_event.h>
-#include <linux/stringify.h>
-#include <linux/limits.h>
-#include <asm/bitsperlong.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-#define MAX_TRACE_ARGS 128
-#define MAX_ARGSTR_LEN 63
-#define MAX_EVENT_NAME_LEN 64
-#define MAX_STRING_SIZE PATH_MAX
-#define KPROBE_EVENT_SYSTEM "kprobes"
-
-/* Reserved field names */
-#define FIELD_STRING_IP "__probe_ip"
-#define FIELD_STRING_RETIP "__probe_ret_ip"
-#define FIELD_STRING_FUNC "__probe_func"
-
-const char *reserved_field_names[] = {
- "common_type",
- "common_flags",
- "common_preempt_count",
- "common_pid",
- "common_tgid",
- FIELD_STRING_IP,
- FIELD_STRING_RETIP,
- FIELD_STRING_FUNC,
-};
-
-/* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
- void *);
-#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
-#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
-
-/* Printing in basic type function template */
-#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
-static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
- const char *name, \
- void *data, void *ent)\
-{ \
- return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
-} \
-static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
-
-DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
-DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
-
-/* data_rloc: data relative location, compatible with u32 */
-#define make_data_rloc(len, roffs) \
- (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
-#define get_rloc_len(dl) ((u32)(dl) >> 16)
-#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
-
-static inline void *get_rloc_data(u32 *dl)
-{
- return (u8 *)dl + get_rloc_offs(*dl);
-}
-
-/* For data_loc conversion */
-static inline void *get_loc_data(u32 *dl, void *ent)
-{
- return (u8 *)ent + get_rloc_offs(*dl);
-}
-
-/*
- * Convert data_rloc to data_loc:
- * data_rloc stores the offset from data_rloc itself, but data_loc
- * stores the offset from event entry.
- */
-#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
-
-/* For defining macros, define string/string_size types */
-typedef u32 string;
-typedef u32 string_size;
-
-/* Print type function for string type */
-static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
- const char *name,
- void *data, void *ent)
-{
- int len = *(u32 *)data >> 16;
-
- if (!len)
- return trace_seq_printf(s, " %s=(fault)", name);
- else
- return trace_seq_printf(s, " %s=\"%s\"", name,
- (const char *)get_loc_data(data, ent));
-}
-static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
-
-/* Data fetch function type */
-typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
-
-struct fetch_param {
- fetch_func_t fn;
- void *data;
-};
-
-static __kprobes void call_fetch(struct fetch_param *fprm,
- struct pt_regs *regs, void *dest)
-{
- return fprm->fn(regs, fprm->data, dest);
-}
-
-#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
-/*
- * Define macro for basic types - we don't need to define s* types, because
- * we have to care only about bitwidth at recording time.
- */
-#define DEFINE_BASIC_FETCH_FUNCS(method) \
-DEFINE_FETCH_##method(u8) \
-DEFINE_FETCH_##method(u16) \
-DEFINE_FETCH_##method(u32) \
-DEFINE_FETCH_##method(u64)
-
-#define CHECK_FETCH_FUNCS(method, fn) \
- (((FETCH_FUNC_NAME(method, u8) == fn) || \
- (FETCH_FUNC_NAME(method, u16) == fn) || \
- (FETCH_FUNC_NAME(method, u32) == fn) || \
- (FETCH_FUNC_NAME(method, u64) == fn) || \
- (FETCH_FUNC_NAME(method, string) == fn) || \
- (FETCH_FUNC_NAME(method, string_size) == fn)) \
- && (fn != NULL))
-
-/* Data fetch function templates */
-#define DEFINE_FETCH_reg(type) \
-static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
- void *offset, void *dest) \
-{ \
- *(type *)dest = (type)regs_get_register(regs, \
- (unsigned int)((unsigned long)offset)); \
-}
-DEFINE_BASIC_FETCH_FUNCS(reg)
-/* No string on the register */
-#define fetch_reg_string NULL
-#define fetch_reg_string_size NULL
-
-#define DEFINE_FETCH_stack(type) \
-static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
- void *offset, void *dest) \
-{ \
- *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
- (unsigned int)((unsigned long)offset)); \
-}
-DEFINE_BASIC_FETCH_FUNCS(stack)
-/* No string on the stack entry */
-#define fetch_stack_string NULL
-#define fetch_stack_string_size NULL
-
-#define DEFINE_FETCH_retval(type) \
-static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
- void *dummy, void *dest) \
-{ \
- *(type *)dest = (type)regs_return_value(regs); \
-}
-DEFINE_BASIC_FETCH_FUNCS(retval)
-/* No string on the retval */
-#define fetch_retval_string NULL
-#define fetch_retval_string_size NULL
-
-#define DEFINE_FETCH_memory(type) \
-static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
- void *addr, void *dest) \
-{ \
- type retval; \
- if (probe_kernel_address(addr, retval)) \
- *(type *)dest = 0; \
- else \
- *(type *)dest = retval; \
-}
-DEFINE_BASIC_FETCH_FUNCS(memory)
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
- * length and relative data location.
- */
-static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
- void *addr, void *dest)
-{
- long ret;
- int maxlen = get_rloc_len(*(u32 *)dest);
- u8 *dst = get_rloc_data(dest);
- u8 *src = addr;
- mm_segment_t old_fs = get_fs();
- if (!maxlen)
- return;
- /*
- * Try to get string again, since the string can be changed while
- * probing.
- */
- set_fs(KERNEL_DS);
- pagefault_disable();
- do
- ret = __copy_from_user_inatomic(dst++, src++, 1);
- while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
- dst[-1] = '\0';
- pagefault_enable();
- set_fs(old_fs);
-
- if (ret < 0) { /* Failed to fetch string */
- ((u8 *)get_rloc_data(dest))[0] = '\0';
- *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
- } else
- *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
- get_rloc_offs(*(u32 *)dest));
-}
-/* Return the length of string -- including null terminal byte */
-static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
- void *addr, void *dest)
-{
- int ret, len = 0;
- u8 c;
- mm_segment_t old_fs = get_fs();
-
- set_fs(KERNEL_DS);
- pagefault_disable();
- do {
- ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
- len++;
- } while (c && ret == 0 && len < MAX_STRING_SIZE);
- pagefault_enable();
- set_fs(old_fs);
-
- if (ret < 0) /* Failed to check the length */
- *(u32 *)dest = 0;
- else
- *(u32 *)dest = len;
-}
-
-/* Memory fetching by symbol */
-struct symbol_cache {
- char *symbol;
- long offset;
- unsigned long addr;
-};
-
-static unsigned long update_symbol_cache(struct symbol_cache *sc)
-{
- sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
- if (sc->addr)
- sc->addr += sc->offset;
- return sc->addr;
-}
-
-static void free_symbol_cache(struct symbol_cache *sc)
-{
- kfree(sc->symbol);
- kfree(sc);
-}
-
-static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
-{
- struct symbol_cache *sc;
-
- if (!sym || strlen(sym) == 0)
- return NULL;
- sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
- if (!sc)
- return NULL;
-
- sc->symbol = kstrdup(sym, GFP_KERNEL);
- if (!sc->symbol) {
- kfree(sc);
- return NULL;
- }
- sc->offset = offset;
- update_symbol_cache(sc);
- return sc;
-}
-
-#define DEFINE_FETCH_symbol(type) \
-static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
- void *data, void *dest) \
-{ \
- struct symbol_cache *sc = data; \
- if (sc->addr) \
- fetch_memory_##type(regs, (void *)sc->addr, dest); \
- else \
- *(type *)dest = 0; \
-}
-DEFINE_BASIC_FETCH_FUNCS(symbol)
-DEFINE_FETCH_symbol(string)
-DEFINE_FETCH_symbol(string_size)
-
-/* Dereference memory access function */
-struct deref_fetch_param {
- struct fetch_param orig;
- long offset;
-};
-
-#define DEFINE_FETCH_deref(type) \
-static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
- void *data, void *dest) \
-{ \
- struct deref_fetch_param *dprm = data; \
- unsigned long addr; \
- call_fetch(&dprm->orig, regs, &addr); \
- if (addr) { \
- addr += dprm->offset; \
- fetch_memory_##type(regs, (void *)addr, dest); \
- } else \
- *(type *)dest = 0; \
-}
-DEFINE_BASIC_FETCH_FUNCS(deref)
-DEFINE_FETCH_deref(string)
-DEFINE_FETCH_deref(string_size)
-
-static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
-{
- if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
- update_deref_fetch_param(data->orig.data);
- else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
- update_symbol_cache(data->orig.data);
-}
-
-static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
-{
- if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
- free_deref_fetch_param(data->orig.data);
- else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
- free_symbol_cache(data->orig.data);
- kfree(data);
-}
-
-/* Bitfield fetch function */
-struct bitfield_fetch_param {
- struct fetch_param orig;
- unsigned char hi_shift;
- unsigned char low_shift;
-};
+#include "trace_probe.h"
-#define DEFINE_FETCH_bitfield(type) \
-static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
- void *data, void *dest) \
-{ \
- struct bitfield_fetch_param *bprm = data; \
- type buf = 0; \
- call_fetch(&bprm->orig, regs, &buf); \
- if (buf) { \
- buf <<= bprm->hi_shift; \
- buf >>= bprm->low_shift; \
- } \
- *(type *)dest = buf; \
-}
-DEFINE_BASIC_FETCH_FUNCS(bitfield)
-#define fetch_bitfield_string NULL
-#define fetch_bitfield_string_size NULL
-
-static __kprobes void
-update_bitfield_fetch_param(struct bitfield_fetch_param *data)
-{
- /*
- * Don't check the bitfield itself, because this must be the
- * last fetch function.
- */
- if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
- update_deref_fetch_param(data->orig.data);
- else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
- update_symbol_cache(data->orig.data);
-}
-
-static __kprobes void
-free_bitfield_fetch_param(struct bitfield_fetch_param *data)
-{
- /*
- * Don't check the bitfield itself, because this must be the
- * last fetch function.
- */
- if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
- free_deref_fetch_param(data->orig.data);
- else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
- free_symbol_cache(data->orig.data);
- kfree(data);
-}
-
-/* Default (unsigned long) fetch type */
-#define __DEFAULT_FETCH_TYPE(t) u##t
-#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
-#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
-#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
-
-/* Fetch types */
-enum {
- FETCH_MTD_reg = 0,
- FETCH_MTD_stack,
- FETCH_MTD_retval,
- FETCH_MTD_memory,
- FETCH_MTD_symbol,
- FETCH_MTD_deref,
- FETCH_MTD_bitfield,
- FETCH_MTD_END,
-};
-
-#define ASSIGN_FETCH_FUNC(method, type) \
- [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
-
-#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
- {.name = _name, \
- .size = _size, \
- .is_signed = sign, \
- .print = PRINT_TYPE_FUNC_NAME(ptype), \
- .fmt = PRINT_TYPE_FMT_NAME(ptype), \
- .fmttype = _fmttype, \
- .fetch = { \
-ASSIGN_FETCH_FUNC(reg, ftype), \
-ASSIGN_FETCH_FUNC(stack, ftype), \
-ASSIGN_FETCH_FUNC(retval, ftype), \
-ASSIGN_FETCH_FUNC(memory, ftype), \
-ASSIGN_FETCH_FUNC(symbol, ftype), \
-ASSIGN_FETCH_FUNC(deref, ftype), \
-ASSIGN_FETCH_FUNC(bitfield, ftype), \
- } \
- }
-
-#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
- __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
-
-#define FETCH_TYPE_STRING 0
-#define FETCH_TYPE_STRSIZE 1
-
-/* Fetch type information table */
-static const struct fetch_type {
- const char *name; /* Name of type */
- size_t size; /* Byte size of type */
- int is_signed; /* Signed flag */
- print_type_func_t print; /* Print functions */
- const char *fmt; /* Fromat string */
- const char *fmttype; /* Name in format file */
- /* Fetch functions */
- fetch_func_t fetch[FETCH_MTD_END];
-} fetch_type_table[] = {
- /* Special types */
- [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
- sizeof(u32), 1, "__data_loc char[]"),
- [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
- string_size, sizeof(u32), 0, "u32"),
- /* Basic types */
- ASSIGN_FETCH_TYPE(u8, u8, 0),
- ASSIGN_FETCH_TYPE(u16, u16, 0),
- ASSIGN_FETCH_TYPE(u32, u32, 0),
- ASSIGN_FETCH_TYPE(u64, u64, 0),
- ASSIGN_FETCH_TYPE(s8, u8, 1),
- ASSIGN_FETCH_TYPE(s16, u16, 1),
- ASSIGN_FETCH_TYPE(s32, u32, 1),
- ASSIGN_FETCH_TYPE(s64, u64, 1),
-};
-
-static const struct fetch_type *find_fetch_type(const char *type)
-{
- int i;
-
- if (!type)
- type = DEFAULT_FETCH_TYPE_STR;
-
- /* Special case: bitfield */
- if (*type == 'b') {
- unsigned long bs;
- type = strchr(type, '/');
- if (!type)
- goto fail;
- type++;
- if (strict_strtoul(type, 0, &bs))
- goto fail;
- switch (bs) {
- case 8:
- return find_fetch_type("u8");
- case 16:
- return find_fetch_type("u16");
- case 32:
- return find_fetch_type("u32");
- case 64:
- return find_fetch_type("u64");
- default:
- goto fail;
- }
- }
-
- for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
- if (strcmp(type, fetch_type_table[i].name) == 0)
- return &fetch_type_table[i];
-fail:
- return NULL;
-}
-
-/* Special function : only accept unsigned long */
-static __kprobes void fetch_stack_address(struct pt_regs *regs,
- void *dummy, void *dest)
-{
- *(unsigned long *)dest = kernel_stack_pointer(regs);
-}
-
-static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
- fetch_func_t orig_fn)
-{
- int i;
-
- if (type != &fetch_type_table[FETCH_TYPE_STRING])
- return NULL; /* Only string type needs size function */
- for (i = 0; i < FETCH_MTD_END; i++)
- if (type->fetch[i] == orig_fn)
- return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
-
- WARN_ON(1); /* This should not happen */
- return NULL;
-}
+#define KPROBE_EVENT_SYSTEM "kprobes"
/**
* Kprobe event core functions
*/
-struct probe_arg {
- struct fetch_param fetch;
- struct fetch_param fetch_size;
- unsigned int offset; /* Offset from argument entry */
- const char *name; /* Name of this argument */
- const char *comm; /* Command of this argument */
- const struct fetch_type *type; /* Type of this argument */
-};
-
-/* Flags for trace_probe */
-#define TP_FLAG_TRACE 1
-#define TP_FLAG_PROFILE 2
-#define TP_FLAG_REGISTERED 4
-
struct trace_probe {
struct list_head list;
struct kretprobe rp; /* Use rp.kp for kprobe use */
static int kretprobe_dispatcher(struct kretprobe_instance *ri,
struct pt_regs *regs);
-/* Check the name is good for event/group/fields */
-static int is_good_name(const char *name)
-{
- if (!isalpha(*name) && *name != '_')
- return 0;
- while (*++name != '\0') {
- if (!isalpha(*name) && !isdigit(*name) && *name != '_')
- return 0;
- }
- return 1;
-}
-
/*
* Allocate new trace_probe and initialize it (including kprobes).
*/
void *addr,
const char *symbol,
unsigned long offs,
- int nargs, int is_return)
+ int nargs, bool is_return)
{
struct trace_probe *tp;
int ret = -ENOMEM;
return ERR_PTR(ret);
}
-static void update_probe_arg(struct probe_arg *arg)
-{
- if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
- update_bitfield_fetch_param(arg->fetch.data);
- else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
- update_deref_fetch_param(arg->fetch.data);
- else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
- update_symbol_cache(arg->fetch.data);
-}
-
-static void free_probe_arg(struct probe_arg *arg)
-{
- if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
- free_bitfield_fetch_param(arg->fetch.data);
- else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
- free_deref_fetch_param(arg->fetch.data);
- else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
- free_symbol_cache(arg->fetch.data);
- kfree(arg->name);
- kfree(arg->comm);
-}
-
static void free_trace_probe(struct trace_probe *tp)
{
int i;
for (i = 0; i < tp->nr_args; i++)
- free_probe_arg(&tp->args[i]);
+ traceprobe_free_probe_arg(&tp->args[i]);
kfree(tp->call.class->system);
kfree(tp->call.name);
return -EINVAL;
for (i = 0; i < tp->nr_args; i++)
- update_probe_arg(&tp->args[i]);
+ traceprobe_update_arg(&tp->args[i]);
/* Set/clear disabled flag according to tp->flag */
if (trace_probe_is_enabled(tp))
.priority = 1 /* Invoked after kprobe module callback */
};
-/* Split symbol and offset. */
-static int split_symbol_offset(char *symbol, unsigned long *offset)
-{
- char *tmp;
- int ret;
-
- if (!offset)
- return -EINVAL;
-
- tmp = strchr(symbol, '+');
- if (tmp) {
- /* skip sign because strict_strtol doesn't accept '+' */
- ret = strict_strtoul(tmp + 1, 0, offset);
- if (ret)
- return ret;
- *tmp = '\0';
- } else
- *offset = 0;
- return 0;
-}
-
-#define PARAM_MAX_ARGS 16
-#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
-
-static int parse_probe_vars(char *arg, const struct fetch_type *t,
- struct fetch_param *f, int is_return)
-{
- int ret = 0;
- unsigned long param;
-
- if (strcmp(arg, "retval") == 0) {
- if (is_return)
- f->fn = t->fetch[FETCH_MTD_retval];
- else
- ret = -EINVAL;
- } else if (strncmp(arg, "stack", 5) == 0) {
- if (arg[5] == '\0') {
- if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
- f->fn = fetch_stack_address;
- else
- ret = -EINVAL;
- } else if (isdigit(arg[5])) {
- ret = strict_strtoul(arg + 5, 10, ¶m);
- if (ret || param > PARAM_MAX_STACK)
- ret = -EINVAL;
- else {
- f->fn = t->fetch[FETCH_MTD_stack];
- f->data = (void *)param;
- }
- } else
- ret = -EINVAL;
- } else
- ret = -EINVAL;
- return ret;
-}
-
-/* Recursive argument parser */
-static int __parse_probe_arg(char *arg, const struct fetch_type *t,
- struct fetch_param *f, int is_return)
-{
- int ret = 0;
- unsigned long param;
- long offset;
- char *tmp;
-
- switch (arg[0]) {
- case '$':
- ret = parse_probe_vars(arg + 1, t, f, is_return);
- break;
- case '%': /* named register */
- ret = regs_query_register_offset(arg + 1);
- if (ret >= 0) {
- f->fn = t->fetch[FETCH_MTD_reg];
- f->data = (void *)(unsigned long)ret;
- ret = 0;
- }
- break;
- case '@': /* memory or symbol */
- if (isdigit(arg[1])) {
- ret = strict_strtoul(arg + 1, 0, ¶m);
- if (ret)
- break;
- f->fn = t->fetch[FETCH_MTD_memory];
- f->data = (void *)param;
- } else {
- ret = split_symbol_offset(arg + 1, &offset);
- if (ret)
- break;
- f->data = alloc_symbol_cache(arg + 1, offset);
- if (f->data)
- f->fn = t->fetch[FETCH_MTD_symbol];
- }
- break;
- case '+': /* deref memory */
- arg++; /* Skip '+', because strict_strtol() rejects it. */
- case '-':
- tmp = strchr(arg, '(');
- if (!tmp)
- break;
- *tmp = '\0';
- ret = strict_strtol(arg, 0, &offset);
- if (ret)
- break;
- arg = tmp + 1;
- tmp = strrchr(arg, ')');
- if (tmp) {
- struct deref_fetch_param *dprm;
- const struct fetch_type *t2 = find_fetch_type(NULL);
- *tmp = '\0';
- dprm = kzalloc(sizeof(struct deref_fetch_param),
- GFP_KERNEL);
- if (!dprm)
- return -ENOMEM;
- dprm->offset = offset;
- ret = __parse_probe_arg(arg, t2, &dprm->orig,
- is_return);
- if (ret)
- kfree(dprm);
- else {
- f->fn = t->fetch[FETCH_MTD_deref];
- f->data = (void *)dprm;
- }
- }
- break;
- }
- if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
- pr_info("%s type has no corresponding fetch method.\n",
- t->name);
- ret = -EINVAL;
- }
- return ret;
-}
-
-#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
-
-/* Bitfield type needs to be parsed into a fetch function */
-static int __parse_bitfield_probe_arg(const char *bf,
- const struct fetch_type *t,
- struct fetch_param *f)
-{
- struct bitfield_fetch_param *bprm;
- unsigned long bw, bo;
- char *tail;
-
- if (*bf != 'b')
- return 0;
-
- bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
- if (!bprm)
- return -ENOMEM;
- bprm->orig = *f;
- f->fn = t->fetch[FETCH_MTD_bitfield];
- f->data = (void *)bprm;
-
- bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
- if (bw == 0 || *tail != '@')
- return -EINVAL;
-
- bf = tail + 1;
- bo = simple_strtoul(bf, &tail, 0);
- if (tail == bf || *tail != '/')
- return -EINVAL;
-
- bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
- bprm->low_shift = bprm->hi_shift + bo;
- return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
-}
-
-/* String length checking wrapper */
-static int parse_probe_arg(char *arg, struct trace_probe *tp,
- struct probe_arg *parg, int is_return)
-{
- const char *t;
- int ret;
-
- if (strlen(arg) > MAX_ARGSTR_LEN) {
- pr_info("Argument is too long.: %s\n", arg);
- return -ENOSPC;
- }
- parg->comm = kstrdup(arg, GFP_KERNEL);
- if (!parg->comm) {
- pr_info("Failed to allocate memory for command '%s'.\n", arg);
- return -ENOMEM;
- }
- t = strchr(parg->comm, ':');
- if (t) {
- arg[t - parg->comm] = '\0';
- t++;
- }
- parg->type = find_fetch_type(t);
- if (!parg->type) {
- pr_info("Unsupported type: %s\n", t);
- return -EINVAL;
- }
- parg->offset = tp->size;
- tp->size += parg->type->size;
- ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
- if (ret >= 0 && t != NULL)
- ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
- if (ret >= 0) {
- parg->fetch_size.fn = get_fetch_size_function(parg->type,
- parg->fetch.fn);
- parg->fetch_size.data = parg->fetch.data;
- }
- return ret;
-}
-
-/* Return 1 if name is reserved or already used by another argument */
-static int conflict_field_name(const char *name,
- struct probe_arg *args, int narg)
-{
- int i;
- for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
- if (strcmp(reserved_field_names[i], name) == 0)
- return 1;
- for (i = 0; i < narg; i++)
- if (strcmp(args[i].name, name) == 0)
- return 1;
- return 0;
-}
-
static int create_trace_probe(int argc, char **argv)
{
/*
*/
struct trace_probe *tp;
int i, ret = 0;
- int is_return = 0, is_delete = 0;
+ bool is_return = false, is_delete = false;
char *symbol = NULL, *event = NULL, *group = NULL;
char *arg;
unsigned long offset = 0;
/* argc must be >= 1 */
if (argv[0][0] == 'p')
- is_return = 0;
+ is_return = false;
else if (argv[0][0] == 'r')
- is_return = 1;
+ is_return = true;
else if (argv[0][0] == '-')
- is_delete = 1;
+ is_delete = true;
else {
pr_info("Probe definition must be started with 'p', 'r' or"
" '-'.\n");
/* a symbol specified */
symbol = argv[1];
/* TODO: support .init module functions */
- ret = split_symbol_offset(symbol, &offset);
+ ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret) {
pr_info("Failed to parse symbol.\n");
return ret;
goto error;
}
- if (conflict_field_name(tp->args[i].name, tp->args, i)) {
+ if (traceprobe_conflict_field_name(tp->args[i].name,
+ tp->args, i)) {
pr_info("Argument[%d] name '%s' conflicts with "
"another field.\n", i, argv[i]);
ret = -EINVAL;
}
/* Parse fetch argument */
- ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
+ ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i],
+ is_return, true);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
return seq_open(file, &probes_seq_op);
}
-static int command_trace_probe(const char *buf)
-{
- char **argv;
- int argc = 0, ret = 0;
-
- argv = argv_split(GFP_KERNEL, buf, &argc);
- if (!argv)
- return -ENOMEM;
-
- if (argc)
- ret = create_trace_probe(argc, argv);
-
- argv_free(argv);
- return ret;
-}
-
-#define WRITE_BUFSIZE 4096
-
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
- char *kbuf, *tmp;
- int ret;
- size_t done;
- size_t size;
-
- kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
- if (!kbuf)
- return -ENOMEM;
-
- ret = done = 0;
- while (done < count) {
- size = count - done;
- if (size >= WRITE_BUFSIZE)
- size = WRITE_BUFSIZE - 1;
- if (copy_from_user(kbuf, buffer + done, size)) {
- ret = -EFAULT;
- goto out;
- }
- kbuf[size] = '\0';
- tmp = strchr(kbuf, '\n');
- if (tmp) {
- *tmp = '\0';
- size = tmp - kbuf + 1;
- } else if (done + size < count) {
- pr_warning("Line length is too long: "
- "Should be less than %d.", WRITE_BUFSIZE);
- ret = -EINVAL;
- goto out;
- }
- done += size;
- /* Remove comments */
- tmp = strchr(kbuf, '#');
- if (tmp)
- *tmp = '\0';
-
- ret = command_trace_probe(kbuf);
- if (ret)
- goto out;
- }
- ret = done;
-out:
- kfree(kbuf);
- return ret;
+ return traceprobe_probes_write(file, buffer, count, ppos,
+ create_trace_probe);
}
static const struct file_operations kprobe_events_ops = {
return TRACE_TYPE_PARTIAL_LINE;
}
-#undef DEFINE_FIELD
-#define DEFINE_FIELD(type, item, name, is_signed) \
- do { \
- ret = trace_define_field(event_call, #type, name, \
- offsetof(typeof(field), item), \
- sizeof(field.item), is_signed, \
- FILTER_OTHER); \
- if (ret) \
- return ret; \
- } while (0)
static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
{
pr_info("Testing kprobe tracing: ");
- ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
- "$stack $stack0 +0($stack)");
+ ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
+ "$stack $stack0 +0($stack)",
+ create_trace_probe);
if (WARN_ON_ONCE(ret)) {
pr_warning("error on probing function entry.\n");
warn++;
enable_trace_probe(tp, TP_FLAG_TRACE);
}
- ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
- "$retval");
+ ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
+ "$retval", create_trace_probe);
if (WARN_ON_ONCE(ret)) {
pr_warning("error on probing function return.\n");
warn++;
} else
disable_trace_probe(tp, TP_FLAG_TRACE);
- ret = command_trace_probe("-:testprobe");
+ ret = traceprobe_command("-:testprobe", create_trace_probe);
if (WARN_ON_ONCE(ret)) {
pr_warning("error on deleting a probe.\n");
warn++;
}
- ret = command_trace_probe("-:testprobe2");
+ ret = traceprobe_command("-:testprobe2", create_trace_probe);
if (WARN_ON_ONCE(ret)) {
pr_warning("error on deleting a probe.\n");
warn++;
--- /dev/null
+/*
+ * Common code for probe-based Dynamic events.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * This code was copied from kernel/trace/trace_kprobe.c written by
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Updates to make this generic:
+ * Copyright (C) IBM Corporation, 2010-2011
+ * Author: Srikar Dronamraju
+ */
+
+#include "trace_probe.h"
+
+const char *reserved_field_names[] = {
+ "common_type",
+ "common_flags",
+ "common_preempt_count",
+ "common_pid",
+ "common_tgid",
+ FIELD_STRING_IP,
+ FIELD_STRING_RETIP,
+ FIELD_STRING_FUNC,
+};
+
+/* Printing function type */
+#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
+#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
+
+/* Printing in basic type function template */
+#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
+static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
+ const char *name, \
+ void *data, void *ent)\
+{ \
+ return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
+} \
+static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
+
+DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
+
+static inline void *get_rloc_data(u32 *dl)
+{
+ return (u8 *)dl + get_rloc_offs(*dl);
+}
+
+/* For data_loc conversion */
+static inline void *get_loc_data(u32 *dl, void *ent)
+{
+ return (u8 *)ent + get_rloc_offs(*dl);
+}
+
+/* For defining macros, define string/string_size types */
+typedef u32 string;
+typedef u32 string_size;
+
+/* Print type function for string type */
+static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
+ const char *name,
+ void *data, void *ent)
+{
+ int len = *(u32 *)data >> 16;
+
+ if (!len)
+ return trace_seq_printf(s, " %s=(fault)", name);
+ else
+ return trace_seq_printf(s, " %s=\"%s\"", name,
+ (const char *)get_loc_data(data, ent));
+}
+
+static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
+
+#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
+/*
+ * Define macro for basic types - we don't need to define s* types, because
+ * we have to care only about bitwidth at recording time.
+ */
+#define DEFINE_BASIC_FETCH_FUNCS(method) \
+DEFINE_FETCH_##method(u8) \
+DEFINE_FETCH_##method(u16) \
+DEFINE_FETCH_##method(u32) \
+DEFINE_FETCH_##method(u64)
+
+#define CHECK_FETCH_FUNCS(method, fn) \
+ (((FETCH_FUNC_NAME(method, u8) == fn) || \
+ (FETCH_FUNC_NAME(method, u16) == fn) || \
+ (FETCH_FUNC_NAME(method, u32) == fn) || \
+ (FETCH_FUNC_NAME(method, u64) == fn) || \
+ (FETCH_FUNC_NAME(method, string) == fn) || \
+ (FETCH_FUNC_NAME(method, string_size) == fn)) \
+ && (fn != NULL))
+
+/* Data fetch function templates */
+#define DEFINE_FETCH_reg(type) \
+static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
+ void *offset, void *dest) \
+{ \
+ *(type *)dest = (type)regs_get_register(regs, \
+ (unsigned int)((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(reg)
+/* No string on the register */
+#define fetch_reg_string NULL
+#define fetch_reg_string_size NULL
+
+#define DEFINE_FETCH_stack(type) \
+static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
+ void *offset, void *dest) \
+{ \
+ *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
+ (unsigned int)((unsigned long)offset)); \
+}
+DEFINE_BASIC_FETCH_FUNCS(stack)
+/* No string on the stack entry */
+#define fetch_stack_string NULL
+#define fetch_stack_string_size NULL
+
+#define DEFINE_FETCH_retval(type) \
+static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
+ void *dummy, void *dest) \
+{ \
+ *(type *)dest = (type)regs_return_value(regs); \
+}
+DEFINE_BASIC_FETCH_FUNCS(retval)
+/* No string on the retval */
+#define fetch_retval_string NULL
+#define fetch_retval_string_size NULL
+
+#define DEFINE_FETCH_memory(type) \
+static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
+ void *addr, void *dest) \
+{ \
+ type retval; \
+ if (probe_kernel_address(addr, retval)) \
+ *(type *)dest = 0; \
+ else \
+ *(type *)dest = retval; \
+}
+DEFINE_BASIC_FETCH_FUNCS(memory)
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
+ * length and relative data location.
+ */
+static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ long ret;
+ int maxlen = get_rloc_len(*(u32 *)dest);
+ u8 *dst = get_rloc_data(dest);
+ u8 *src = addr;
+ mm_segment_t old_fs = get_fs();
+
+ if (!maxlen)
+ return;
+
+ /*
+ * Try to get string again, since the string can be changed while
+ * probing.
+ */
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+
+ do
+ ret = __copy_from_user_inatomic(dst++, src++, 1);
+ while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
+
+ dst[-1] = '\0';
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) { /* Failed to fetch string */
+ ((u8 *)get_rloc_data(dest))[0] = '\0';
+ *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
+ } else {
+ *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
+ get_rloc_offs(*(u32 *)dest));
+ }
+}
+
+/* Return the length of string -- including null terminal byte */
+static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+ void *addr, void *dest)
+{
+ mm_segment_t old_fs;
+ int ret, len = 0;
+ u8 c;
+
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+
+ do {
+ ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+ len++;
+ } while (c && ret == 0 && len < MAX_STRING_SIZE);
+
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) /* Failed to check the length */
+ *(u32 *)dest = 0;
+ else
+ *(u32 *)dest = len;
+}
+
+/* Memory fetching by symbol */
+struct symbol_cache {
+ char *symbol;
+ long offset;
+ unsigned long addr;
+};
+
+static unsigned long update_symbol_cache(struct symbol_cache *sc)
+{
+ sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
+
+ if (sc->addr)
+ sc->addr += sc->offset;
+
+ return sc->addr;
+}
+
+static void free_symbol_cache(struct symbol_cache *sc)
+{
+ kfree(sc->symbol);
+ kfree(sc);
+}
+
+static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
+{
+ struct symbol_cache *sc;
+
+ if (!sym || strlen(sym) == 0)
+ return NULL;
+
+ sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
+ if (!sc)
+ return NULL;
+
+ sc->symbol = kstrdup(sym, GFP_KERNEL);
+ if (!sc->symbol) {
+ kfree(sc);
+ return NULL;
+ }
+ sc->offset = offset;
+ update_symbol_cache(sc);
+
+ return sc;
+}
+
+#define DEFINE_FETCH_symbol(type) \
+static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct symbol_cache *sc = data; \
+ if (sc->addr) \
+ fetch_memory_##type(regs, (void *)sc->addr, dest); \
+ else \
+ *(type *)dest = 0; \
+}
+DEFINE_BASIC_FETCH_FUNCS(symbol)
+DEFINE_FETCH_symbol(string)
+DEFINE_FETCH_symbol(string_size)
+
+/* Dereference memory access function */
+struct deref_fetch_param {
+ struct fetch_param orig;
+ long offset;
+};
+
+#define DEFINE_FETCH_deref(type) \
+static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct deref_fetch_param *dprm = data; \
+ unsigned long addr; \
+ call_fetch(&dprm->orig, regs, &addr); \
+ if (addr) { \
+ addr += dprm->offset; \
+ fetch_memory_##type(regs, (void *)addr, dest); \
+ } else \
+ *(type *)dest = 0; \
+}
+DEFINE_BASIC_FETCH_FUNCS(deref)
+DEFINE_FETCH_deref(string)
+DEFINE_FETCH_deref(string_size)
+
+static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+{
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
+{
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ free_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ free_symbol_cache(data->orig.data);
+ kfree(data);
+}
+
+/* Bitfield fetch function */
+struct bitfield_fetch_param {
+ struct fetch_param orig;
+ unsigned char hi_shift;
+ unsigned char low_shift;
+};
+
+#define DEFINE_FETCH_bitfield(type) \
+static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct bitfield_fetch_param *bprm = data; \
+ type buf = 0; \
+ call_fetch(&bprm->orig, regs, &buf); \
+ if (buf) { \
+ buf <<= bprm->hi_shift; \
+ buf >>= bprm->low_shift; \
+ } \
+ *(type *)dest = buf; \
+}
+
+DEFINE_BASIC_FETCH_FUNCS(bitfield)
+#define fetch_bitfield_string NULL
+#define fetch_bitfield_string_size NULL
+
+static __kprobes void
+update_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+ /*
+ * Don't check the bitfield itself, because this must be the
+ * last fetch function.
+ */
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ update_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ update_symbol_cache(data->orig.data);
+}
+
+static __kprobes void
+free_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+ /*
+ * Don't check the bitfield itself, because this must be the
+ * last fetch function.
+ */
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ free_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ free_symbol_cache(data->orig.data);
+
+ kfree(data);
+}
+
+/* Default (unsigned long) fetch type */
+#define __DEFAULT_FETCH_TYPE(t) u##t
+#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
+#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
+#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
+
+#define ASSIGN_FETCH_FUNC(method, type) \
+ [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
+
+#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
+ {.name = _name, \
+ .size = _size, \
+ .is_signed = sign, \
+ .print = PRINT_TYPE_FUNC_NAME(ptype), \
+ .fmt = PRINT_TYPE_FMT_NAME(ptype), \
+ .fmttype = _fmttype, \
+ .fetch = { \
+ASSIGN_FETCH_FUNC(reg, ftype), \
+ASSIGN_FETCH_FUNC(stack, ftype), \
+ASSIGN_FETCH_FUNC(retval, ftype), \
+ASSIGN_FETCH_FUNC(memory, ftype), \
+ASSIGN_FETCH_FUNC(symbol, ftype), \
+ASSIGN_FETCH_FUNC(deref, ftype), \
+ASSIGN_FETCH_FUNC(bitfield, ftype), \
+ } \
+ }
+
+#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
+ __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+
+#define FETCH_TYPE_STRING 0
+#define FETCH_TYPE_STRSIZE 1
+
+/* Fetch type information table */
+static const struct fetch_type fetch_type_table[] = {
+ /* Special types */
+ [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+ sizeof(u32), 1, "__data_loc char[]"),
+ [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+ string_size, sizeof(u32), 0, "u32"),
+ /* Basic types */
+ ASSIGN_FETCH_TYPE(u8, u8, 0),
+ ASSIGN_FETCH_TYPE(u16, u16, 0),
+ ASSIGN_FETCH_TYPE(u32, u32, 0),
+ ASSIGN_FETCH_TYPE(u64, u64, 0),
+ ASSIGN_FETCH_TYPE(s8, u8, 1),
+ ASSIGN_FETCH_TYPE(s16, u16, 1),
+ ASSIGN_FETCH_TYPE(s32, u32, 1),
+ ASSIGN_FETCH_TYPE(s64, u64, 1),
+};
+
+static const struct fetch_type *find_fetch_type(const char *type)
+{
+ int i;
+
+ if (!type)
+ type = DEFAULT_FETCH_TYPE_STR;
+
+ /* Special case: bitfield */
+ if (*type == 'b') {
+ unsigned long bs;
+
+ type = strchr(type, '/');
+ if (!type)
+ goto fail;
+
+ type++;
+ if (strict_strtoul(type, 0, &bs))
+ goto fail;
+
+ switch (bs) {
+ case 8:
+ return find_fetch_type("u8");
+ case 16:
+ return find_fetch_type("u16");
+ case 32:
+ return find_fetch_type("u32");
+ case 64:
+ return find_fetch_type("u64");
+ default:
+ goto fail;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
+ if (strcmp(type, fetch_type_table[i].name) == 0)
+ return &fetch_type_table[i];
+
+fail:
+ return NULL;
+}
+
+/* Special function : only accept unsigned long */
+static __kprobes void fetch_stack_address(struct pt_regs *regs,
+ void *dummy, void *dest)
+{
+ *(unsigned long *)dest = kernel_stack_pointer(regs);
+}
+
+static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
+ fetch_func_t orig_fn)
+{
+ int i;
+
+ if (type != &fetch_type_table[FETCH_TYPE_STRING])
+ return NULL; /* Only string type needs size function */
+
+ for (i = 0; i < FETCH_MTD_END; i++)
+ if (type->fetch[i] == orig_fn)
+ return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
+
+ WARN_ON(1); /* This should not happen */
+
+ return NULL;
+}
+
+/* Split symbol and offset. */
+int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
+{
+ char *tmp;
+ int ret;
+
+ if (!offset)
+ return -EINVAL;
+
+ tmp = strchr(symbol, '+');
+ if (tmp) {
+ /* skip sign because strict_strtol doesn't accept '+' */
+ ret = strict_strtoul(tmp + 1, 0, offset);
+ if (ret)
+ return ret;
+
+ *tmp = '\0';
+ } else
+ *offset = 0;
+
+ return 0;
+}
+
+#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
+
+static int parse_probe_vars(char *arg, const struct fetch_type *t,
+ struct fetch_param *f, bool is_return)
+{
+ int ret = 0;
+ unsigned long param;
+
+ if (strcmp(arg, "retval") == 0) {
+ if (is_return)
+ f->fn = t->fetch[FETCH_MTD_retval];
+ else
+ ret = -EINVAL;
+ } else if (strncmp(arg, "stack", 5) == 0) {
+ if (arg[5] == '\0') {
+ if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
+ f->fn = fetch_stack_address;
+ else
+ ret = -EINVAL;
+ } else if (isdigit(arg[5])) {
+ ret = strict_strtoul(arg + 5, 10, ¶m);
+ if (ret || param > PARAM_MAX_STACK)
+ ret = -EINVAL;
+ else {
+ f->fn = t->fetch[FETCH_MTD_stack];
+ f->data = (void *)param;
+ }
+ } else
+ ret = -EINVAL;
+ } else
+ ret = -EINVAL;
+
+ return ret;
+}
+
+/* Recursive argument parser */
+static int parse_probe_arg(char *arg, const struct fetch_type *t,
+ struct fetch_param *f, bool is_return, bool is_kprobe)
+{
+ unsigned long param;
+ long offset;
+ char *tmp;
+ int ret;
+
+ ret = 0;
+
+ /* Until uprobe_events supports only reg arguments */
+ if (!is_kprobe && arg[0] != '%')
+ return -EINVAL;
+
+ switch (arg[0]) {
+ case '$':
+ ret = parse_probe_vars(arg + 1, t, f, is_return);
+ break;
+
+ case '%': /* named register */
+ ret = regs_query_register_offset(arg + 1);
+ if (ret >= 0) {
+ f->fn = t->fetch[FETCH_MTD_reg];
+ f->data = (void *)(unsigned long)ret;
+ ret = 0;
+ }
+ break;
+
+ case '@': /* memory or symbol */
+ if (isdigit(arg[1])) {
+ ret = strict_strtoul(arg + 1, 0, ¶m);
+ if (ret)
+ break;
+
+ f->fn = t->fetch[FETCH_MTD_memory];
+ f->data = (void *)param;
+ } else {
+ ret = traceprobe_split_symbol_offset(arg + 1, &offset);
+ if (ret)
+ break;
+
+ f->data = alloc_symbol_cache(arg + 1, offset);
+ if (f->data)
+ f->fn = t->fetch[FETCH_MTD_symbol];
+ }
+ break;
+
+ case '+': /* deref memory */
+ arg++; /* Skip '+', because strict_strtol() rejects it. */
+ case '-':
+ tmp = strchr(arg, '(');
+ if (!tmp)
+ break;
+
+ *tmp = '\0';
+ ret = strict_strtol(arg, 0, &offset);
+
+ if (ret)
+ break;
+
+ arg = tmp + 1;
+ tmp = strrchr(arg, ')');
+
+ if (tmp) {
+ struct deref_fetch_param *dprm;
+ const struct fetch_type *t2;
+
+ t2 = find_fetch_type(NULL);
+ *tmp = '\0';
+ dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
+
+ if (!dprm)
+ return -ENOMEM;
+
+ dprm->offset = offset;
+ ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
+ is_kprobe);
+ if (ret)
+ kfree(dprm);
+ else {
+ f->fn = t->fetch[FETCH_MTD_deref];
+ f->data = (void *)dprm;
+ }
+ }
+ break;
+ }
+ if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
+ pr_info("%s type has no corresponding fetch method.\n", t->name);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
+
+/* Bitfield type needs to be parsed into a fetch function */
+static int __parse_bitfield_probe_arg(const char *bf,
+ const struct fetch_type *t,
+ struct fetch_param *f)
+{
+ struct bitfield_fetch_param *bprm;
+ unsigned long bw, bo;
+ char *tail;
+
+ if (*bf != 'b')
+ return 0;
+
+ bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
+ if (!bprm)
+ return -ENOMEM;
+
+ bprm->orig = *f;
+ f->fn = t->fetch[FETCH_MTD_bitfield];
+ f->data = (void *)bprm;
+ bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
+
+ if (bw == 0 || *tail != '@')
+ return -EINVAL;
+
+ bf = tail + 1;
+ bo = simple_strtoul(bf, &tail, 0);
+
+ if (tail == bf || *tail != '/')
+ return -EINVAL;
+
+ bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
+ bprm->low_shift = bprm->hi_shift + bo;
+
+ return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
+}
+
+/* String length checking wrapper */
+int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
+ struct probe_arg *parg, bool is_return, bool is_kprobe)
+{
+ const char *t;
+ int ret;
+
+ if (strlen(arg) > MAX_ARGSTR_LEN) {
+ pr_info("Argument is too long.: %s\n", arg);
+ return -ENOSPC;
+ }
+ parg->comm = kstrdup(arg, GFP_KERNEL);
+ if (!parg->comm) {
+ pr_info("Failed to allocate memory for command '%s'.\n", arg);
+ return -ENOMEM;
+ }
+ t = strchr(parg->comm, ':');
+ if (t) {
+ arg[t - parg->comm] = '\0';
+ t++;
+ }
+ parg->type = find_fetch_type(t);
+ if (!parg->type) {
+ pr_info("Unsupported type: %s\n", t);
+ return -EINVAL;
+ }
+ parg->offset = *size;
+ *size += parg->type->size;
+ ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
+
+ if (ret >= 0 && t != NULL)
+ ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
+
+ if (ret >= 0) {
+ parg->fetch_size.fn = get_fetch_size_function(parg->type,
+ parg->fetch.fn);
+ parg->fetch_size.data = parg->fetch.data;
+ }
+
+ return ret;
+}
+
+/* Return 1 if name is reserved or already used by another argument */
+int traceprobe_conflict_field_name(const char *name,
+ struct probe_arg *args, int narg)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
+ if (strcmp(reserved_field_names[i], name) == 0)
+ return 1;
+
+ for (i = 0; i < narg; i++)
+ if (strcmp(args[i].name, name) == 0)
+ return 1;
+
+ return 0;
+}
+
+void traceprobe_update_arg(struct probe_arg *arg)
+{
+ if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+ update_bitfield_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+ update_deref_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
+ update_symbol_cache(arg->fetch.data);
+}
+
+void traceprobe_free_probe_arg(struct probe_arg *arg)
+{
+ if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+ free_bitfield_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+ free_deref_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
+ free_symbol_cache(arg->fetch.data);
+
+ kfree(arg->name);
+ kfree(arg->comm);
+}
+
+int traceprobe_command(const char *buf, int (*createfn)(int, char **))
+{
+ char **argv;
+ int argc, ret;
+
+ argc = 0;
+ ret = 0;
+ argv = argv_split(GFP_KERNEL, buf, &argc);
+ if (!argv)
+ return -ENOMEM;
+
+ if (argc)
+ ret = createfn(argc, argv);
+
+ argv_free(argv);
+
+ return ret;
+}
+
+#define WRITE_BUFSIZE 4096
+
+ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos,
+ int (*createfn)(int, char **))
+{
+ char *kbuf, *tmp;
+ int ret = 0;
+ size_t done = 0;
+ size_t size;
+
+ kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ while (done < count) {
+ size = count - done;
+
+ if (size >= WRITE_BUFSIZE)
+ size = WRITE_BUFSIZE - 1;
+
+ if (copy_from_user(kbuf, buffer + done, size)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ kbuf[size] = '\0';
+ tmp = strchr(kbuf, '\n');
+
+ if (tmp) {
+ *tmp = '\0';
+ size = tmp - kbuf + 1;
+ } else if (done + size < count) {
+ pr_warning("Line length is too long: "
+ "Should be less than %d.", WRITE_BUFSIZE);
+ ret = -EINVAL;
+ goto out;
+ }
+ done += size;
+ /* Remove comments */
+ tmp = strchr(kbuf, '#');
+
+ if (tmp)
+ *tmp = '\0';
+
+ ret = traceprobe_command(kbuf, createfn);
+ if (ret)
+ goto out;
+ }
+ ret = done;
+
+out:
+ kfree(kbuf);
+
+ return ret;
+}
--- /dev/null
+/*
+ * Common header file for probe-based Dynamic events.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * This code was copied from kernel/trace/trace_kprobe.h written by
+ * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
+ *
+ * Updates to make this generic:
+ * Copyright (C) IBM Corporation, 2010-2011
+ * Author: Srikar Dronamraju
+ */
+
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/debugfs.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/ptrace.h>
+#include <linux/perf_event.h>
+#include <linux/kprobes.h>
+#include <linux/stringify.h>
+#include <linux/limits.h>
+#include <linux/uaccess.h>
+#include <asm/bitsperlong.h>
+
+#include "trace.h"
+#include "trace_output.h"
+
+#define MAX_TRACE_ARGS 128
+#define MAX_ARGSTR_LEN 63
+#define MAX_EVENT_NAME_LEN 64
+#define MAX_STRING_SIZE PATH_MAX
+
+/* Reserved field names */
+#define FIELD_STRING_IP "__probe_ip"
+#define FIELD_STRING_RETIP "__probe_ret_ip"
+#define FIELD_STRING_FUNC "__probe_func"
+
+#undef DEFINE_FIELD
+#define DEFINE_FIELD(type, item, name, is_signed) \
+ do { \
+ ret = trace_define_field(event_call, #type, name, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item), is_signed, \
+ FILTER_OTHER); \
+ if (ret) \
+ return ret; \
+ } while (0)
+
+
+/* Flags for trace_probe */
+#define TP_FLAG_TRACE 1
+#define TP_FLAG_PROFILE 2
+#define TP_FLAG_REGISTERED 4
+#define TP_FLAG_UPROBE 8
+
+
+/* data_rloc: data relative location, compatible with u32 */
+#define make_data_rloc(len, roffs) \
+ (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
+#define get_rloc_len(dl) ((u32)(dl) >> 16)
+#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
+
+/*
+ * Convert data_rloc to data_loc:
+ * data_rloc stores the offset from data_rloc itself, but data_loc
+ * stores the offset from event entry.
+ */
+#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
+
+/* Data fetch function type */
+typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
+/* Printing function type */
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
+
+/* Fetch types */
+enum {
+ FETCH_MTD_reg = 0,
+ FETCH_MTD_stack,
+ FETCH_MTD_retval,
+ FETCH_MTD_memory,
+ FETCH_MTD_symbol,
+ FETCH_MTD_deref,
+ FETCH_MTD_bitfield,
+ FETCH_MTD_END,
+};
+
+/* Fetch type information table */
+struct fetch_type {
+ const char *name; /* Name of type */
+ size_t size; /* Byte size of type */
+ int is_signed; /* Signed flag */
+ print_type_func_t print; /* Print functions */
+ const char *fmt; /* Fromat string */
+ const char *fmttype; /* Name in format file */
+ /* Fetch functions */
+ fetch_func_t fetch[FETCH_MTD_END];
+};
+
+struct fetch_param {
+ fetch_func_t fn;
+ void *data;
+};
+
+struct probe_arg {
+ struct fetch_param fetch;
+ struct fetch_param fetch_size;
+ unsigned int offset; /* Offset from argument entry */
+ const char *name; /* Name of this argument */
+ const char *comm; /* Command of this argument */
+ const struct fetch_type *type; /* Type of this argument */
+};
+
+static inline __kprobes void call_fetch(struct fetch_param *fprm,
+ struct pt_regs *regs, void *dest)
+{
+ return fprm->fn(regs, fprm->data, dest);
+}
+
+/* Check the name is good for event/group/fields */
+static inline int is_good_name(const char *name)
+{
+ if (!isalpha(*name) && *name != '_')
+ return 0;
+ while (*++name != '\0') {
+ if (!isalpha(*name) && !isdigit(*name) && *name != '_')
+ return 0;
+ }
+ return 1;
+}
+
+extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
+ struct probe_arg *parg, bool is_return, bool is_kprobe);
+
+extern int traceprobe_conflict_field_name(const char *name,
+ struct probe_arg *args, int narg);
+
+extern void traceprobe_update_arg(struct probe_arg *arg);
+extern void traceprobe_free_probe_arg(struct probe_arg *arg);
+
+extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
+
+extern ssize_t traceprobe_probes_write(struct file *file,
+ const char __user *buffer, size_t count, loff_t *ppos,
+ int (*createfn)(int, char**));
+
+extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
--- /dev/null
+/*
+ * uprobes-based tracing events
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (C) IBM Corporation, 2010-2012
+ * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/uprobes.h>
+#include <linux/namei.h>
+
+#include "trace_probe.h"
+
+#define UPROBE_EVENT_SYSTEM "uprobes"
+
+/*
+ * uprobe event core functions
+ */
+struct trace_uprobe;
+struct uprobe_trace_consumer {
+ struct uprobe_consumer cons;
+ struct trace_uprobe *tu;
+};
+
+struct trace_uprobe {
+ struct list_head list;
+ struct ftrace_event_class class;
+ struct ftrace_event_call call;
+ struct uprobe_trace_consumer *consumer;
+ struct inode *inode;
+ char *filename;
+ unsigned long offset;
+ unsigned long nhit;
+ unsigned int flags; /* For TP_FLAG_* */
+ ssize_t size; /* trace entry size */
+ unsigned int nr_args;
+ struct probe_arg args[];
+};
+
+#define SIZEOF_TRACE_UPROBE(n) \
+ (offsetof(struct trace_uprobe, args) + \
+ (sizeof(struct probe_arg) * (n)))
+
+static int register_uprobe_event(struct trace_uprobe *tu);
+static void unregister_uprobe_event(struct trace_uprobe *tu);
+
+static DEFINE_MUTEX(uprobe_lock);
+static LIST_HEAD(uprobe_list);
+
+static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
+
+/*
+ * Allocate new trace_uprobe and initialize it (including uprobes).
+ */
+static struct trace_uprobe *
+alloc_trace_uprobe(const char *group, const char *event, int nargs)
+{
+ struct trace_uprobe *tu;
+
+ if (!event || !is_good_name(event))
+ return ERR_PTR(-EINVAL);
+
+ if (!group || !is_good_name(group))
+ return ERR_PTR(-EINVAL);
+
+ tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
+ if (!tu)
+ return ERR_PTR(-ENOMEM);
+
+ tu->call.class = &tu->class;
+ tu->call.name = kstrdup(event, GFP_KERNEL);
+ if (!tu->call.name)
+ goto error;
+
+ tu->class.system = kstrdup(group, GFP_KERNEL);
+ if (!tu->class.system)
+ goto error;
+
+ INIT_LIST_HEAD(&tu->list);
+ return tu;
+
+error:
+ kfree(tu->call.name);
+ kfree(tu);
+
+ return ERR_PTR(-ENOMEM);
+}
+
+static void free_trace_uprobe(struct trace_uprobe *tu)
+{
+ int i;
+
+ for (i = 0; i < tu->nr_args; i++)
+ traceprobe_free_probe_arg(&tu->args[i]);
+
+ iput(tu->inode);
+ kfree(tu->call.class->system);
+ kfree(tu->call.name);
+ kfree(tu->filename);
+ kfree(tu);
+}
+
+static struct trace_uprobe *find_probe_event(const char *event, const char *group)
+{
+ struct trace_uprobe *tu;
+
+ list_for_each_entry(tu, &uprobe_list, list)
+ if (strcmp(tu->call.name, event) == 0 &&
+ strcmp(tu->call.class->system, group) == 0)
+ return tu;
+
+ return NULL;
+}
+
+/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
+static void unregister_trace_uprobe(struct trace_uprobe *tu)
+{
+ list_del(&tu->list);
+ unregister_uprobe_event(tu);
+ free_trace_uprobe(tu);
+}
+
+/* Register a trace_uprobe and probe_event */
+static int register_trace_uprobe(struct trace_uprobe *tu)
+{
+ struct trace_uprobe *old_tp;
+ int ret;
+
+ mutex_lock(&uprobe_lock);
+
+ /* register as an event */
+ old_tp = find_probe_event(tu->call.name, tu->call.class->system);
+ if (old_tp)
+ /* delete old event */
+ unregister_trace_uprobe(old_tp);
+
+ ret = register_uprobe_event(tu);
+ if (ret) {
+ pr_warning("Failed to register probe event(%d)\n", ret);
+ goto end;
+ }
+
+ list_add_tail(&tu->list, &uprobe_list);
+
+end:
+ mutex_unlock(&uprobe_lock);
+
+ return ret;
+}
+
+/*
+ * Argument syntax:
+ * - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS]
+ *
+ * - Remove uprobe: -:[GRP/]EVENT
+ */
+static int create_trace_uprobe(int argc, char **argv)
+{
+ struct trace_uprobe *tu;
+ struct inode *inode;
+ char *arg, *event, *group, *filename;
+ char buf[MAX_EVENT_NAME_LEN];
+ struct path path;
+ unsigned long offset;
+ bool is_delete;
+ int i, ret;
+
+ inode = NULL;
+ ret = 0;
+ is_delete = false;
+ event = NULL;
+ group = NULL;
+
+ /* argc must be >= 1 */
+ if (argv[0][0] == '-')
+ is_delete = true;
+ else if (argv[0][0] != 'p') {
+ pr_info("Probe definition must be started with 'p', 'r' or" " '-'.\n");
+ return -EINVAL;
+ }
+
+ if (argv[0][1] == ':') {
+ event = &argv[0][2];
+ arg = strchr(event, '/');
+
+ if (arg) {
+ group = event;
+ event = arg + 1;
+ event[-1] = '\0';
+
+ if (strlen(group) == 0) {
+ pr_info("Group name is not specified\n");
+ return -EINVAL;
+ }
+ }
+ if (strlen(event) == 0) {
+ pr_info("Event name is not specified\n");
+ return -EINVAL;
+ }
+ }
+ if (!group)
+ group = UPROBE_EVENT_SYSTEM;
+
+ if (is_delete) {
+ if (!event) {
+ pr_info("Delete command needs an event name.\n");
+ return -EINVAL;
+ }
+ mutex_lock(&uprobe_lock);
+ tu = find_probe_event(event, group);
+
+ if (!tu) {
+ mutex_unlock(&uprobe_lock);
+ pr_info("Event %s/%s doesn't exist.\n", group, event);
+ return -ENOENT;
+ }
+ /* delete an event */
+ unregister_trace_uprobe(tu);
+ mutex_unlock(&uprobe_lock);
+ return 0;
+ }
+
+ if (argc < 2) {
+ pr_info("Probe point is not specified.\n");
+ return -EINVAL;
+ }
+ if (isdigit(argv[1][0])) {
+ pr_info("probe point must be have a filename.\n");
+ return -EINVAL;
+ }
+ arg = strchr(argv[1], ':');
+ if (!arg)
+ goto fail_address_parse;
+
+ *arg++ = '\0';
+ filename = argv[1];
+ ret = kern_path(filename, LOOKUP_FOLLOW, &path);
+ if (ret)
+ goto fail_address_parse;
+
+ ret = strict_strtoul(arg, 0, &offset);
+ if (ret)
+ goto fail_address_parse;
+
+ inode = igrab(path.dentry->d_inode);
+
+ argc -= 2;
+ argv += 2;
+
+ /* setup a probe */
+ if (!event) {
+ char *tail = strrchr(filename, '/');
+ char *ptr;
+
+ ptr = kstrdup((tail ? tail + 1 : filename), GFP_KERNEL);
+ if (!ptr) {
+ ret = -ENOMEM;
+ goto fail_address_parse;
+ }
+
+ tail = ptr;
+ ptr = strpbrk(tail, ".-_");
+ if (ptr)
+ *ptr = '\0';
+
+ snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
+ event = buf;
+ kfree(tail);
+ }
+
+ tu = alloc_trace_uprobe(group, event, argc);
+ if (IS_ERR(tu)) {
+ pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
+ ret = PTR_ERR(tu);
+ goto fail_address_parse;
+ }
+ tu->offset = offset;
+ tu->inode = inode;
+ tu->filename = kstrdup(filename, GFP_KERNEL);
+
+ if (!tu->filename) {
+ pr_info("Failed to allocate filename.\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ /* parse arguments */
+ ret = 0;
+ for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
+ /* Increment count for freeing args in error case */
+ tu->nr_args++;
+
+ /* Parse argument name */
+ arg = strchr(argv[i], '=');
+ if (arg) {
+ *arg++ = '\0';
+ tu->args[i].name = kstrdup(argv[i], GFP_KERNEL);
+ } else {
+ arg = argv[i];
+ /* If argument name is omitted, set "argN" */
+ snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
+ tu->args[i].name = kstrdup(buf, GFP_KERNEL);
+ }
+
+ if (!tu->args[i].name) {
+ pr_info("Failed to allocate argument[%d] name.\n", i);
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ if (!is_good_name(tu->args[i].name)) {
+ pr_info("Invalid argument[%d] name: %s\n", i, tu->args[i].name);
+ ret = -EINVAL;
+ goto error;
+ }
+
+ if (traceprobe_conflict_field_name(tu->args[i].name, tu->args, i)) {
+ pr_info("Argument[%d] name '%s' conflicts with "
+ "another field.\n", i, argv[i]);
+ ret = -EINVAL;
+ goto error;
+ }
+
+ /* Parse fetch argument */
+ ret = traceprobe_parse_probe_arg(arg, &tu->size, &tu->args[i], false, false);
+ if (ret) {
+ pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
+ goto error;
+ }
+ }
+
+ ret = register_trace_uprobe(tu);
+ if (ret)
+ goto error;
+ return 0;
+
+error:
+ free_trace_uprobe(tu);
+ return ret;
+
+fail_address_parse:
+ if (inode)
+ iput(inode);
+
+ pr_info("Failed to parse address.\n");
+
+ return ret;
+}
+
+static void cleanup_all_probes(void)
+{
+ struct trace_uprobe *tu;
+
+ mutex_lock(&uprobe_lock);
+ while (!list_empty(&uprobe_list)) {
+ tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
+ unregister_trace_uprobe(tu);
+ }
+ mutex_unlock(&uprobe_lock);
+}
+
+/* Probes listing interfaces */
+static void *probes_seq_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&uprobe_lock);
+ return seq_list_start(&uprobe_list, *pos);
+}
+
+static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ return seq_list_next(v, &uprobe_list, pos);
+}
+
+static void probes_seq_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&uprobe_lock);
+}
+
+static int probes_seq_show(struct seq_file *m, void *v)
+{
+ struct trace_uprobe *tu = v;
+ int i;
+
+ seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name);
+ seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
+
+ for (i = 0; i < tu->nr_args; i++)
+ seq_printf(m, " %s=%s", tu->args[i].name, tu->args[i].comm);
+
+ seq_printf(m, "\n");
+ return 0;
+}
+
+static const struct seq_operations probes_seq_op = {
+ .start = probes_seq_start,
+ .next = probes_seq_next,
+ .stop = probes_seq_stop,
+ .show = probes_seq_show
+};
+
+static int probes_open(struct inode *inode, struct file *file)
+{
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
+ cleanup_all_probes();
+
+ return seq_open(file, &probes_seq_op);
+}
+
+static ssize_t probes_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
+}
+
+static const struct file_operations uprobe_events_ops = {
+ .owner = THIS_MODULE,
+ .open = probes_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .write = probes_write,
+};
+
+/* Probes profiling interfaces */
+static int probes_profile_seq_show(struct seq_file *m, void *v)
+{
+ struct trace_uprobe *tu = v;
+
+ seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->call.name, tu->nhit);
+ return 0;
+}
+
+static const struct seq_operations profile_seq_op = {
+ .start = probes_seq_start,
+ .next = probes_seq_next,
+ .stop = probes_seq_stop,
+ .show = probes_profile_seq_show
+};
+
+static int profile_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &profile_seq_op);
+}
+
+static const struct file_operations uprobe_profile_ops = {
+ .owner = THIS_MODULE,
+ .open = profile_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/* uprobe handler */
+static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
+{
+ struct uprobe_trace_entry_head *entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ u8 *data;
+ int size, i, pc;
+ unsigned long irq_flags;
+ struct ftrace_event_call *call = &tu->call;
+
+ tu->nhit++;
+
+ local_save_flags(irq_flags);
+ pc = preempt_count();
+
+ size = sizeof(*entry) + tu->size;
+
+ event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
+ size, irq_flags, pc);
+ if (!event)
+ return;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ data = (u8 *)&entry[1];
+ for (i = 0; i < tu->nr_args; i++)
+ call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
+
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+}
+
+/* Event entry printers */
+static enum print_line_t
+print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
+{
+ struct uprobe_trace_entry_head *field;
+ struct trace_seq *s = &iter->seq;
+ struct trace_uprobe *tu;
+ u8 *data;
+ int i;
+
+ field = (struct uprobe_trace_entry_head *)iter->ent;
+ tu = container_of(event, struct trace_uprobe, call.event);
+
+ if (!trace_seq_printf(s, "%s: (", tu->call.name))
+ goto partial;
+
+ if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
+ goto partial;
+
+ if (!trace_seq_puts(s, ")"))
+ goto partial;
+
+ data = (u8 *)&field[1];
+ for (i = 0; i < tu->nr_args; i++) {
+ if (!tu->args[i].type->print(s, tu->args[i].name,
+ data + tu->args[i].offset, field))
+ goto partial;
+ }
+
+ if (trace_seq_puts(s, "\n"))
+ return TRACE_TYPE_HANDLED;
+
+partial:
+ return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int probe_event_enable(struct trace_uprobe *tu, int flag)
+{
+ struct uprobe_trace_consumer *utc;
+ int ret = 0;
+
+ if (!tu->inode || tu->consumer)
+ return -EINTR;
+
+ utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
+ if (!utc)
+ return -EINTR;
+
+ utc->cons.handler = uprobe_dispatcher;
+ utc->cons.filter = NULL;
+ ret = uprobe_register(tu->inode, tu->offset, &utc->cons);
+ if (ret) {
+ kfree(utc);
+ return ret;
+ }
+
+ tu->flags |= flag;
+ utc->tu = tu;
+ tu->consumer = utc;
+
+ return 0;
+}
+
+static void probe_event_disable(struct trace_uprobe *tu, int flag)
+{
+ if (!tu->inode || !tu->consumer)
+ return;
+
+ uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);
+ tu->flags &= ~flag;
+ kfree(tu->consumer);
+ tu->consumer = NULL;
+}
+
+static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
+{
+ int ret, i;
+ struct uprobe_trace_entry_head field;
+ struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data;
+
+ DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
+ /* Set argument names as fields */
+ for (i = 0; i < tu->nr_args; i++) {
+ ret = trace_define_field(event_call, tu->args[i].type->fmttype,
+ tu->args[i].name,
+ sizeof(field) + tu->args[i].offset,
+ tu->args[i].type->size,
+ tu->args[i].type->is_signed,
+ FILTER_OTHER);
+
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+#define LEN_OR_ZERO (len ? len - pos : 0)
+static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len)
+{
+ const char *fmt, *arg;
+ int i;
+ int pos = 0;
+
+ fmt = "(%lx)";
+ arg = "REC->" FIELD_STRING_IP;
+
+ /* When len=0, we just calculate the needed length */
+
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
+
+ for (i = 0; i < tu->nr_args; i++) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
+ tu->args[i].name, tu->args[i].type->fmt);
+ }
+
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
+
+ for (i = 0; i < tu->nr_args; i++) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
+ tu->args[i].name);
+ }
+
+ return pos; /* return the length of print_fmt */
+}
+#undef LEN_OR_ZERO
+
+static int set_print_fmt(struct trace_uprobe *tu)
+{
+ char *print_fmt;
+ int len;
+
+ /* First: called with 0 length to calculate the needed length */
+ len = __set_print_fmt(tu, NULL, 0);
+ print_fmt = kmalloc(len + 1, GFP_KERNEL);
+ if (!print_fmt)
+ return -ENOMEM;
+
+ /* Second: actually write the @print_fmt */
+ __set_print_fmt(tu, print_fmt, len + 1);
+ tu->call.print_fmt = print_fmt;
+
+ return 0;
+}
+
+#ifdef CONFIG_PERF_EVENTS
+/* uprobe profile handler */
+static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
+{
+ struct ftrace_event_call *call = &tu->call;
+ struct uprobe_trace_entry_head *entry;
+ struct hlist_head *head;
+ u8 *data;
+ int size, __size, i;
+ int rctx;
+
+ __size = sizeof(*entry) + tu->size;
+ size = ALIGN(__size + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+ if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
+ return;
+
+ preempt_disable();
+
+ entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
+ if (!entry)
+ goto out;
+
+ entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+ data = (u8 *)&entry[1];
+ for (i = 0; i < tu->nr_args; i++)
+ call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
+
+ head = this_cpu_ptr(call->perf_events);
+ perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
+
+ out:
+ preempt_enable();
+}
+#endif /* CONFIG_PERF_EVENTS */
+
+static
+int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
+{
+ struct trace_uprobe *tu = (struct trace_uprobe *)event->data;
+
+ switch (type) {
+ case TRACE_REG_REGISTER:
+ return probe_event_enable(tu, TP_FLAG_TRACE);
+
+ case TRACE_REG_UNREGISTER:
+ probe_event_disable(tu, TP_FLAG_TRACE);
+ return 0;
+
+#ifdef CONFIG_PERF_EVENTS
+ case TRACE_REG_PERF_REGISTER:
+ return probe_event_enable(tu, TP_FLAG_PROFILE);
+
+ case TRACE_REG_PERF_UNREGISTER:
+ probe_event_disable(tu, TP_FLAG_PROFILE);
+ return 0;
+#endif
+ default:
+ return 0;
+ }
+ return 0;
+}
+
+static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
+{
+ struct uprobe_trace_consumer *utc;
+ struct trace_uprobe *tu;
+
+ utc = container_of(con, struct uprobe_trace_consumer, cons);
+ tu = utc->tu;
+ if (!tu || tu->consumer != utc)
+ return 0;
+
+ if (tu->flags & TP_FLAG_TRACE)
+ uprobe_trace_func(tu, regs);
+
+#ifdef CONFIG_PERF_EVENTS
+ if (tu->flags & TP_FLAG_PROFILE)
+ uprobe_perf_func(tu, regs);
+#endif
+ return 0;
+}
+
+static struct trace_event_functions uprobe_funcs = {
+ .trace = print_uprobe_event
+};
+
+static int register_uprobe_event(struct trace_uprobe *tu)
+{
+ struct ftrace_event_call *call = &tu->call;
+ int ret;
+
+ /* Initialize ftrace_event_call */
+ INIT_LIST_HEAD(&call->class->fields);
+ call->event.funcs = &uprobe_funcs;
+ call->class->define_fields = uprobe_event_define_fields;
+
+ if (set_print_fmt(tu) < 0)
+ return -ENOMEM;
+
+ ret = register_ftrace_event(&call->event);
+ if (!ret) {
+ kfree(call->print_fmt);
+ return -ENODEV;
+ }
+ call->flags = 0;
+ call->class->reg = trace_uprobe_register;
+ call->data = tu;
+ ret = trace_add_event_call(call);
+
+ if (ret) {
+ pr_info("Failed to register uprobe event: %s\n", call->name);
+ kfree(call->print_fmt);
+ unregister_ftrace_event(&call->event);
+ }
+
+ return ret;
+}
+
+static void unregister_uprobe_event(struct trace_uprobe *tu)
+{
+ /* tu->event is unregistered in trace_remove_event_call() */
+ trace_remove_event_call(&tu->call);
+ kfree(tu->call.print_fmt);
+ tu->call.print_fmt = NULL;
+}
+
+/* Make a trace interface for controling probe points */
+static __init int init_uprobe_trace(void)
+{
+ struct dentry *d_tracer;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return 0;
+
+ trace_create_file("uprobe_events", 0644, d_tracer,
+ NULL, &uprobe_events_ops);
+ /* Profile interface */
+ trace_create_file("uprobe_profile", 0444, d_tracer,
+ NULL, &uprobe_profile_ops);
+ return 0;
+}
+
+fs_initcall(init_uprobe_trace);
if (end <= vma->vm_start)
return;
+ if (vma->vm_file)
+ uprobe_munmap(vma, start, end);
+
if (vma->vm_flags & VM_ACCOUNT)
*nr_accounted += (end - start) >> PAGE_SHIFT;
#include <linux/perf_event.h>
#include <linux/audit.h>
#include <linux/khugepaged.h>
+#include <linux/uprobes.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
if (file) {
mapping = file->f_mapping;
- if (!(vma->vm_flags & VM_NONLINEAR))
+ if (!(vma->vm_flags & VM_NONLINEAR)) {
root = &mapping->i_mmap;
+ uprobe_munmap(vma, vma->vm_start, vma->vm_end);
+
+ if (adjust_next)
+ uprobe_munmap(next, next->vm_start,
+ next->vm_end);
+ }
+
mutex_lock(&mapping->i_mmap_mutex);
if (insert) {
/*
if (mapping)
mutex_unlock(&mapping->i_mmap_mutex);
+ if (root) {
+ uprobe_mmap(vma);
+
+ if (adjust_next)
+ uprobe_mmap(next);
+ }
+
if (remove_next) {
if (file) {
+ uprobe_munmap(next, next->vm_start, next->vm_end);
fput(file);
if (next->vm_flags & VM_EXECUTABLE)
removed_exe_file_vma(mm);
goto again;
}
}
+ if (insert && file)
+ uprobe_mmap(insert);
validate_mm(mm);
mm->locked_vm += (len >> PAGE_SHIFT);
} else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
make_pages_present(addr, addr + len);
+
+ if (file && uprobe_mmap(vma))
+ /* matching probes but cannot insert */
+ goto unmap_and_free_vma;
+
return addr;
unmap_and_free_vma:
if ((vma->vm_flags & VM_ACCOUNT) &&
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
+
+ if (vma->vm_file && uprobe_mmap(vma))
+ return -EINVAL;
+
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
}
new_vma->vm_pgoff = pgoff;
if (new_vma->vm_file) {
get_file(new_vma->vm_file);
+
+ if (uprobe_mmap(new_vma))
+ goto out_free_mempol;
+
if (vma->vm_flags & VM_EXECUTABLE)
added_exe_file_vma(mm);
}
git.openpandora.org / pandora-kernel.git / commitdiff