* Rusty Russell).
* 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
* interface to access function arguments.
- * 2004-Oct Jim Keniston <kenistoj@us.ibm.com> and Prasanna S Panchamukhi
- * <prasanna@in.ibm.com> adapted for x86_64
+ * 2004-Oct Jim Keniston <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
+ * <prasanna@in.ibm.com> adapted for x86_64 from i386.
* 2005-Mar Roland McGrath <roland@redhat.com>
* Fixed to handle %rip-relative addressing mode correctly.
- * 2005-May Rusty Lynch <rusty.lynch@intel.com>
- * Added function return probes functionality
+ * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston
+ * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
+ * <prasanna@in.ibm.com> added function-return probes.
+ * 2005-May Rusty Lynch <rusty.lynch@intel.com>
+ * Added function return probes functionality
+ * 2006-Feb Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added
+ * kprobe-booster and kretprobe-booster for i386.
* 2007-Dec Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster
* and kretprobe-booster for x86-64
+ * 2007-Dec Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven
+ * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
+ * unified x86 kprobes code.
*/
#include <linux/kprobes.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+#ifdef CONFIG_X86_64
#define stack_addr(regs) ((unsigned long *)regs->sp)
+#else
+/*
+ * "®s->sp" looks wrong, but it's correct for x86_32. x86_32 CPUs
+ * don't save the ss and esp registers if the CPU is already in kernel
+ * mode when it traps. So for kprobes, regs->sp and regs->ss are not
+ * the [nonexistent] saved stack pointer and ss register, but rather
+ * the top 8 bytes of the pre-int3 stack. So ®s->sp happens to
+ * point to the top of the pre-int3 stack.
+ */
+#define stack_addr(regs) ((unsigned long *)®s->sp)
+#endif
#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) | \
}
/*
- * returns non-zero if opcode is boostable.
- * RIP relative instructions are adjusted at copying time
+ * Returns non-zero if opcode is boostable.
+ * RIP relative instructions are adjusted at copying time in 64 bits mode
*/
static __always_inline int can_boost(kprobe_opcode_t *opcodes)
{
}
switch (opcode & 0xf0) {
+#ifdef CONFIG_X86_64
case 0x40:
goto retry; /* REX prefix is boostable */
+#endif
case 0x60:
if (0x63 < opcode && opcode < 0x67)
goto retry; /* prefixes */
}
/*
- * returns non-zero if opcode modifies the interrupt flag.
+ * Returns non-zero if opcode modifies the interrupt flag.
*/
static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
{
case 0x9d: /* popf/popfd */
return 1;
}
-
+#ifdef CONFIG_X86_64
/*
* on 64 bit x86, 0x40-0x4f are prefixes so we need to look
* at the next byte instead.. but of course not recurse infinitely
*/
if (*insn >= 0x40 && *insn <= 0x4f)
return is_IF_modifier(++insn);
+#endif
return 0;
}
+#ifdef CONFIG_X86_64
/*
* Adjust the displacement if the instruction uses the %rip-relative
* addressing mode.
if ((*insn & 0xf0) == 0x40)
++insn;
- if (*insn == 0x0f) { /* Two-byte opcode. */
+ if (*insn == 0x0f) {
+ /* Two-byte opcode. */
++insn;
need_modrm = test_bit(*insn,
(unsigned long *)twobyte_has_modrm);
- } else /* One-byte opcode. */
+ } else
+ /* One-byte opcode. */
need_modrm = test_bit(*insn,
(unsigned long *)onebyte_has_modrm);
if (need_modrm) {
u8 modrm = *++insn;
- if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */
+ if ((modrm & 0xc7) == 0x05) {
+ /* %rip+disp32 addressing mode */
/* Displacement follows ModRM byte. */
++insn;
/*
}
}
}
+#endif
static void __kprobes arch_copy_kprobe(struct kprobe *p)
{
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+#ifdef CONFIG_X86_64
fix_riprel(p);
+#endif
if (can_boost(p->addr))
p->ainsn.boostable = 0;
else
static __always_inline void clear_btf(void)
{
if (test_thread_flag(TIF_DEBUGCTLMSR))
- wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
}
static __always_inline void restore_btf(void)
{
if (test_thread_flag(TIF_DEBUGCTLMSR))
- wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
+ wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
regs->flags &= ~TF_MASK;
regs->flags |= kcb->kprobe_saved_flags;
goto no_kprobe;
+#ifdef CONFIG_X86_64
} else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
/* TODO: Provide re-entrancy from
* post_kprobes_handler() and avoid exception
regs->ip = (unsigned long)p->addr;
reset_current_kprobe();
return 1;
+#endif
}
/* We have reentered the kprobe_handler(), since
* another probe was hit while within the handler.
goto no_kprobe;
}
p = __get_cpu_var(current_kprobe);
- if (p->break_handler && p->break_handler(p, regs)) {
+ if (p->break_handler && p->break_handler(p, regs))
goto ss_probe;
- }
}
goto no_kprobe;
}
*/
void __kprobes kretprobe_trampoline_holder(void)
{
- asm volatile ( ".global kretprobe_trampoline\n"
+ asm volatile (
+ ".global kretprobe_trampoline\n"
"kretprobe_trampoline: \n"
+#ifdef CONFIG_X86_64
/* We don't bother saving the ss register */
" pushq %rsp\n"
" pushfq\n"
/* Skip orig_ax, ip, cs */
" addq $24, %rsp\n"
" popfq\n"
+#else
+ " pushf\n"
+ /*
+ * Skip cs, ip, orig_ax.
+ * trampoline_handler() will plug in these values
+ */
+ " subl $12, %esp\n"
+ " pushl %fs\n"
+ " pushl %ds\n"
+ " pushl %es\n"
+ " pushl %eax\n"
+ " pushl %ebp\n"
+ " pushl %edi\n"
+ " pushl %esi\n"
+ " pushl %edx\n"
+ " pushl %ecx\n"
+ " pushl %ebx\n"
+ " movl %esp, %eax\n"
+ " call trampoline_handler\n"
+ /* Move flags to cs */
+ " movl 52(%esp), %edx\n"
+ " movl %edx, 48(%esp)\n"
+ /* Replace saved flags with true return address. */
+ " movl %eax, 52(%esp)\n"
+ " popl %ebx\n"
+ " popl %ecx\n"
+ " popl %edx\n"
+ " popl %esi\n"
+ " popl %edi\n"
+ " popl %ebp\n"
+ " popl %eax\n"
+ /* Skip ip, orig_ax, es, ds, fs */
+ " addl $20, %esp\n"
+ " popf\n"
+#endif
" ret\n");
}
/*
* Called from kretprobe_trampoline
*/
-fastcall void * __kprobes trampoline_handler(struct pt_regs *regs)
+void * __kprobes trampoline_handler(struct pt_regs *regs)
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
struct hlist_node *node, *tmp;
unsigned long flags, orig_ret_address = 0;
- unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline;
+ unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
INIT_HLIST_HEAD(&empty_rp);
spin_lock_irqsave(&kretprobe_lock, flags);
head = kretprobe_inst_table_head(current);
/* fixup registers */
+#ifdef CONFIG_X86_64
regs->cs = __KERNEL_CS;
+#else
+ regs->cs = __KERNEL_CS | get_kernel_rpl();
+#endif
regs->ip = trampoline_address;
regs->orig_ax = ~0UL;
unsigned long orig_ip = (unsigned long)p->addr;
kprobe_opcode_t *insn = p->ainsn.insn;
+#ifdef CONFIG_X86_64
/*skip the REX prefix*/
if (*insn >= 0x40 && *insn <= 0x4f)
insn++;
+#endif
regs->flags &= ~TF_MASK;
switch (*insn) {
case 0xe8: /* call relative - Fix return addr */
*tos = orig_ip + (*tos - copy_ip);
break;
+#ifndef CONFIG_X86_64
+ case 0x9a: /* call absolute -- same as call absolute, indirect */
+ *tos = orig_ip + (*tos - copy_ip);
+ goto no_change;
+#endif
case 0xff:
if ((insn[1] & 0x30) == 0x10) {
/*
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- const struct exception_table_entry *fixup;
- switch(kcb->kprobe_status) {
+ switch (kcb->kprobe_status) {
case KPROBE_HIT_SS:
case KPROBE_REENTER:
/*
* In case the user-specified fault handler returned
* zero, try to fix up.
*/
- fixup = search_exception_tables(regs->ip);
- if (fixup) {
- regs->ip = fixup->fixup;
- return 1;
+#ifdef CONFIG_X86_64
+ {
+ const struct exception_table_entry *fixup;
+ fixup = search_exception_tables(regs->ip);
+ if (fixup) {
+ regs->ip = fixup->fixup;
+ return 1;
+ }
}
-
+#else
+ if (fixup_exception(regs))
+ return 1;
+#endif
/*
* fixup routine could not handle it,
* Let do_page_fault() fix it.
* the argument area.
*/
memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr,
- MIN_STACK_SIZE(addr));
+ MIN_STACK_SIZE(addr));
regs->flags &= ~IF_MASK;
trace_hardirqs_off();
regs->ip = (unsigned long)(jp->entry);
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- asm volatile (" xchg %%rbx,%%rsp \n"
- " int3 \n"
- " .globl jprobe_return_end \n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
+ asm volatile (
+#ifdef CONFIG_X86_64
+ " xchg %%rbx,%%rsp \n"
+#else
+ " xchgl %%ebx,%%esp \n"
+#endif
+ " int3 \n"
+ " .globl jprobe_return_end\n"
+ " jprobe_return_end: \n"
+ " nop \n"::"b"
+ (kcb->jprobe_saved_sp):"memory");
}
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
u8 *addr = (u8 *) (regs->ip - 1);
struct jprobe *jp = container_of(p, struct jprobe, kp);
- if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
+ if ((addr > (u8 *) jprobe_return) &&
+ (addr < (u8 *) jprobe_return_end)) {
if (stack_addr(regs) != kcb->jprobe_saved_sp) {
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
- printk("current sp %p does not match saved sp %p\n",
+ printk(KERN_ERR
+ "current sp %p does not match saved sp %p\n",
stack_addr(regs), kcb->jprobe_saved_sp);
- printk("Saved registers for jprobe %p\n", jp);
+ printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
show_registers(saved_regs);
- printk("Current registers\n");
+ printk(KERN_ERR "Current registers\n");
show_registers(regs);
BUG();
}
git.openpandora.org / pandora-kernel.git / blobdiff