x86(-64) are the last architectures still using the page fault notifier
cruft for the kprobes page fault hook. This patch converts them to the
proper direct calls, and removes the now unused pagefault notifier bits
aswell as the cruft in kprobes.c that was related to this mess.
I know Andi didn't really like this, but all other architecture maintainers
agreed the direct calls are much better and besides the obvious cruft
removal a common way of dealing with kprobes across architectures is
important aswell.
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc64]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
20 files changed:
-static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
ret = NOTIFY_STOP;
break;
case DIE_GPF:
ret = NOTIFY_STOP;
break;
case DIE_GPF:
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
ret = NOTIFY_STOP;
break;
case DIE_GPF:
ret = NOTIFY_STOP;
break;
case DIE_GPF:
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/desc.h>
#include <asm/system.h>
#include <asm/desc.h>
extern void die(const char *,struct pt_regs *,long);
extern void die(const char *,struct pt_regs *,long);
-static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-int register_page_fault_notifier(struct notifier_block *nb)
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs)
- vmalloc_sync_all();
- return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
-}
-EXPORT_SYMBOL_GPL(register_page_fault_notifier);
+ int ret = 0;
+
+ /* kprobe_running() needs smp_processor_id() */
+ if (!user_mode_vm(regs)) {
+ preempt_disable();
+ if (kprobe_running() && kprobe_fault_handler(regs, 14))
+ ret = 1;
+ preempt_enable();
+ }
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
-EXPORT_SYMBOL_GPL(unregister_page_fault_notifier);
-
-static inline int notify_page_fault(struct pt_regs *regs, long err)
+#else
+static inline int notify_page_fault(struct pt_regs *regs)
- struct die_args args = {
- .regs = regs,
- .str = "page fault",
- .err = err,
- .trapnr = 14,
- .signr = SIGSEGV
- };
- return atomic_notifier_call_chain(¬ify_page_fault_chain,
- DIE_PAGE_FAULT, &args);
/*
* Return EIP plus the CS segment base. The segment limit is also
/*
* Return EIP plus the CS segment base. The segment limit is also
if (unlikely(address >= TASK_SIZE)) {
if (!(error_code & 0x0000000d) && vmalloc_fault(address) >= 0)
return;
if (unlikely(address >= TASK_SIZE)) {
if (!(error_code & 0x0000000d) && vmalloc_fault(address) >= 0)
return;
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
goto bad_area_nosemaphore;
}
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return;
/* It's safe to allow irq's after cr2 has been saved and the vmalloc
return;
/* It's safe to allow irq's after cr2 has been saved and the vmalloc
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/pgalloc.h>
#define PF_RSVD (1<<3)
#define PF_INSTR (1<<4)
#define PF_RSVD (1<<3)
#define PF_INSTR (1<<4)
-static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs)
- vmalloc_sync_all();
- return atomic_notifier_chain_register(¬ify_page_fault_chain, nb);
-}
-EXPORT_SYMBOL_GPL(register_page_fault_notifier);
+ int ret = 0;
+
+ /* kprobe_running() needs smp_processor_id() */
+ if (!user_mode(regs)) {
+ preempt_disable();
+ if (kprobe_running() && kprobe_fault_handler(regs, 14))
+ ret = 1;
+ preempt_enable();
+ }
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_unregister(¬ify_page_fault_chain, nb);
-EXPORT_SYMBOL_GPL(unregister_page_fault_notifier);
-
-static inline int notify_page_fault(struct pt_regs *regs, long err)
+#else
+static inline int notify_page_fault(struct pt_regs *regs)
- struct die_args args = {
- .regs = regs,
- .str = "page fault",
- .err = err,
- .trapnr = 14,
- .signr = SIGSEGV
- };
- return atomic_notifier_call_chain(¬ify_page_fault_chain,
- DIE_PAGE_FAULT, &args);
/* Sometimes the CPU reports invalid exceptions on prefetch.
Check that here and ignore.
/* Sometimes the CPU reports invalid exceptions on prefetch.
Check that here and ignore.
if (vmalloc_fault(address) >= 0)
return;
}
if (vmalloc_fault(address) >= 0)
return;
}
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
goto bad_area_nosemaphore;
}
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+ if (notify_page_fault(regs))
return;
if (likely(regs->eflags & X86_EFLAGS_IF))
return;
if (likely(regs->eflags & X86_EFLAGS_IF))
#ifndef __ASM_AVR32_KDEBUG_H
#define __ASM_AVR32_KDEBUG_H
#ifndef __ASM_AVR32_KDEBUG_H
#define __ASM_AVR32_KDEBUG_H
-#include <linux/notifier.h>
-
/* Grossly misnamed. */
enum die_val {
DIE_BREAKPOINT,
DIE_SSTEP,
};
/* Grossly misnamed. */
enum die_val {
DIE_BREAKPOINT,
DIE_SSTEP,
};
-/*
- * These are only here because kprobes.c wants them to implement a
- * blatant layering violation. Will hopefully go away soon once all
- * architectures are updated.
- */
-static inline int register_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-static inline int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-
#endif /* __ASM_AVR32_KDEBUG_H */
#endif /* __ASM_AVR32_KDEBUG_H */
#define BREAKPOINT_INSTRUCTION 0xd673 /* breakpoint */
#define MAX_INSN_SIZE 2
#define BREAKPOINT_INSTRUCTION 0xd673 /* breakpoint */
#define MAX_INSN_SIZE 2
-#define ARCH_INACTIVE_KPROBE_COUNT 1
-
#define arch_remove_kprobe(p) do { } while (0)
/* Architecture specific copy of original instruction */
#define arch_remove_kprobe(p) do { } while (0)
/* Architecture specific copy of original instruction */
* 2005-Oct Keith Owens <kaos@sgi.com>. Expand notify_die to cover more
* events.
*/
* 2005-Oct Keith Owens <kaos@sgi.com>. Expand notify_die to cover more
* events.
*/
-#include <linux/notifier.h>
-
-/*
- * These are only here because kprobes.c wants them to implement a
- * blatant layering violation. Will hopefully go away soon once all
- * architectures are updated.
- */
-static inline int register_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-static inline int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
enum die_val {
DIE_BREAK = 1,
enum die_val {
DIE_BREAK = 1,
};
#define ARCH_SUPPORTS_KRETPROBES
};
#define ARCH_SUPPORTS_KRETPROBES
-#define ARCH_INACTIVE_KPROBE_COUNT 1
#define SLOT0_OPCODE_SHIFT (37)
#define SLOT1_p1_OPCODE_SHIFT (37 - (64-46))
#define SLOT0_OPCODE_SHIFT (37)
#define SLOT1_p1_OPCODE_SHIFT (37 - (64-46))
#define _ASM_POWERPC_KDEBUG_H
#ifdef __KERNEL__
#define _ASM_POWERPC_KDEBUG_H
#ifdef __KERNEL__
-/* nearly identical to x86_64/i386 code */
-
-#include <linux/notifier.h>
-
-/*
- * These are only here because kprobes.c wants them to implement a
- * blatant layering violation. Will hopefully go away soon once all
- * architectures are updated.
- */
-static inline int register_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-static inline int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-extern struct atomic_notifier_head powerpc_die_chain;
-
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
#endif
#define ARCH_SUPPORTS_KRETPROBES
#endif
#define ARCH_SUPPORTS_KRETPROBES
-#define ARCH_INACTIVE_KPROBE_COUNT 1
#define flush_insn_slot(p) do { } while (0)
void kretprobe_trampoline(void);
#define flush_insn_slot(p) do { } while (0)
void kretprobe_trampoline(void);
/*
* Feb 2006 Ported to s390 <grundym@us.ibm.com>
*/
/*
* Feb 2006 Ported to s390 <grundym@us.ibm.com>
*/
-#include <linux/notifier.h>
-/*
- * These are only here because kprobes.c wants them to implement a
- * blatant layering violation. Will hopefully go away soon once all
- * architectures are updated.
- */
-static inline int register_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-static inline int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-
enum die_val {
DIE_OOPS = 1,
DIE_BPT,
enum die_val {
DIE_OOPS = 1,
DIE_BPT,
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
-#define ARCH_INACTIVE_KPROBE_COUNT 0
#define KPROBE_SWAP_INST 0x10
#define KPROBE_SWAP_INST 0x10
#ifndef __ASM_SH_KDEBUG_H
#define __ASM_SH_KDEBUG_H
#ifndef __ASM_SH_KDEBUG_H
#define __ASM_SH_KDEBUG_H
-#include <linux/notifier.h>
-
/* Grossly misnamed. */
enum die_val {
DIE_TRAP,
/* Grossly misnamed. */
enum die_val {
DIE_TRAP,
#ifndef _SPARC64_KDEBUG_H
#define _SPARC64_KDEBUG_H
#ifndef _SPARC64_KDEBUG_H
#define _SPARC64_KDEBUG_H
-/* Nearly identical to x86_64/i386 code. */
-
-#include <linux/notifier.h>
-
-/*
- * These are only here because kprobes.c wants them to implement a
- * blatant layering violation. Will hopefully go away soon once all
- * architectures are updated.
- */
-static inline int register_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-static inline int unregister_page_fault_notifier(struct notifier_block *nb)
-{
- return 0;
-}
-
extern void bad_trap(struct pt_regs *, long);
/* Grossly misnamed. */
extern void bad_trap(struct pt_regs *, long);
/* Grossly misnamed. */
#define MAX_INSN_SIZE 2
#define arch_remove_kprobe(p) do {} while (0)
#define MAX_INSN_SIZE 2
#define arch_remove_kprobe(p) do {} while (0)
-#define ARCH_INACTIVE_KPROBE_COUNT 0
#define flush_insn_slot(p) \
do { flushi(&(p)->ainsn.insn[0]); \
#define flush_insn_slot(p) \
do { flushi(&(p)->ainsn.insn[0]); \
* Aug-05 2004 Ported by Prasanna S Panchamukhi <prasanna@in.ibm.com>
* from x86_64 architecture.
*/
* Aug-05 2004 Ported by Prasanna S Panchamukhi <prasanna@in.ibm.com>
* from x86_64 architecture.
*/
-#include <linux/notifier.h>
-extern int register_page_fault_notifier(struct notifier_block *);
-extern int unregister_page_fault_notifier(struct notifier_block *);
-
-
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
DIE_GPF,
DIE_CALL,
DIE_NMI_IPI,
DIE_GPF,
DIE_CALL,
DIE_NMI_IPI,
#ifndef _X86_64_KDEBUG_H
#define _X86_64_KDEBUG_H 1
#ifndef _X86_64_KDEBUG_H
#define _X86_64_KDEBUG_H 1
-#include <linux/notifier.h>
+#include <linux/compiler.h>
-extern int register_page_fault_notifier(struct notifier_block *);
-extern int unregister_page_fault_notifier(struct notifier_block *);
-
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
/* Grossly misnamed. */
enum die_val {
DIE_OOPS = 1,
DIE_GPF,
DIE_CALL,
DIE_NMI_IPI,
DIE_GPF,
DIE_CALL,
DIE_NMI_IPI,
};
extern void printk_address(unsigned long address);
};
extern void printk_address(unsigned long address);
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
-#define ARCH_INACTIVE_KPROBE_COUNT 0
#define flush_insn_slot(p) do { } while (0)
void arch_remove_kprobe(struct kprobe *p);
#define flush_insn_slot(p) do { } while (0)
void arch_remove_kprobe(struct kprobe *p);
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
+extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
#endif /* _ASM_KPROBES_H */
#endif /* _ASM_KPROBES_H */
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define ARCH_SUPPORTS_KRETPROBES
-#define ARCH_INACTIVE_KPROBE_COUNT 1
void kretprobe_trampoline(void);
extern void arch_remove_kprobe(struct kprobe *p);
void kretprobe_trampoline(void);
extern void arch_remove_kprobe(struct kprobe *p);
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
-static atomic_t kprobe_count;
/* NOTE: change this value only with kprobe_mutex held */
static bool kprobe_enabled;
/* NOTE: change this value only with kprobe_mutex held */
static bool kprobe_enabled;
DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
-static struct notifier_block kprobe_page_fault_nb = {
- .notifier_call = kprobe_exceptions_notify,
- .priority = 0x7fffffff /* we need to notified first */
-};
-
#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
/*
* kprobe->ainsn.insn points to the copy of the instruction to be
#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
/*
* kprobe->ainsn.insn points to the copy of the instruction to be
old_p = get_kprobe(p->addr);
if (old_p) {
ret = register_aggr_kprobe(old_p, p);
old_p = get_kprobe(p->addr);
if (old_p) {
ret = register_aggr_kprobe(old_p, p);
- if (!ret)
- atomic_inc(&kprobe_count);
hlist_add_head_rcu(&p->hlist,
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
hlist_add_head_rcu(&p->hlist,
&kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
- if (kprobe_enabled) {
- if (atomic_add_return(1, &kprobe_count) == \
- (ARCH_INACTIVE_KPROBE_COUNT + 1))
- register_page_fault_notifier(&kprobe_page_fault_nb);
-
out:
mutex_unlock(&kprobe_mutex);
out:
mutex_unlock(&kprobe_mutex);
}
mutex_unlock(&kprobe_mutex);
}
}
mutex_unlock(&kprobe_mutex);
}
-
- /* Call unregister_page_fault_notifier()
- * if no probes are active
- */
- mutex_lock(&kprobe_mutex);
- if (atomic_add_return(-1, &kprobe_count) == \
- ARCH_INACTIVE_KPROBE_COUNT)
- unregister_page_fault_notifier(&kprobe_page_fault_nb);
- mutex_unlock(&kprobe_mutex);
- return;
}
static struct notifier_block kprobe_exceptions_nb = {
}
static struct notifier_block kprobe_exceptions_nb = {
INIT_HLIST_HEAD(&kprobe_table[i]);
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
}
INIT_HLIST_HEAD(&kprobe_table[i]);
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
}
- atomic_set(&kprobe_count, 0);
/* By default, kprobes are enabled */
kprobe_enabled = true;
/* By default, kprobes are enabled */
kprobe_enabled = true;
if (kprobe_enabled)
goto already_enabled;
if (kprobe_enabled)
goto already_enabled;
- /*
- * Re-register the page fault notifier only if there are any
- * active probes at the time of enabling kprobes globally
- */
- if (atomic_read(&kprobe_count) > ARCH_INACTIVE_KPROBE_COUNT)
- register_page_fault_notifier(&kprobe_page_fault_nb);
-
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
mutex_unlock(&kprobe_mutex);
/* Allow all currently running kprobes to complete */
synchronize_sched();
mutex_unlock(&kprobe_mutex);
/* Allow all currently running kprobes to complete */
synchronize_sched();
-
- mutex_lock(&kprobe_mutex);
- /* Unconditionally unregister the page_fault notifier */
- unregister_page_fault_notifier(&kprobe_page_fault_nb);
already_disabled:
mutex_unlock(&kprobe_mutex);
already_disabled:
mutex_unlock(&kprobe_mutex);