Commit 2326c770 authored by bibo,mao's avatar bibo,mao Committed by Linus Torvalds
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[PATCH] kprobe handler: discard user space trap 



Currently kprobe handler traps only happen in kernel space, so function
kprobe_exceptions_notify should skip traps which happen in user space.
This patch modifies this, and it is based on 2.6.16-rc4.

Signed-off-by: default avatarbibo mao <bibo.mao@intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: <hiramatu@sdl.hitachi.co.jp>
Signed-off-by: default avatarPrasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c6fd91f0

arch/i386/kernel/kprobes.c

+6 −13
Original line number Diff line number Diff line
@@ -203,13 +203,14 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) 
{

	struct kprobe *p;

	int ret = 0;

	kprobe_opcode_t *addr = NULL;

	unsigned long *lp;

	kprobe_opcode_t *addr;

	struct kprobe_ctlblk *kcb;

#ifdef CONFIG_PREEMPT

	unsigned pre_preempt_count = preempt_count();

#endif /* CONFIG_PREEMPT */



	addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t));



	/*

	 * We don't want to be preempted for the entire

	 * duration of kprobe processing
@@ -217,17 +218,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) 
	preempt_disable();

	kcb = get_kprobe_ctlblk();



	/* Check if the application is using LDT entry for its code segment and

	 * calculate the address by reading the base address from the LDT entry.

	 */

	if ((regs->xcs & 4) && (current->mm)) {

		lp = (unsigned long *) ((unsigned long)((regs->xcs >> 3) * 8)

					+ (char *) current->mm->context.ldt);

		addr = (kprobe_opcode_t *) (get_desc_base(lp) + regs->eip -

						sizeof(kprobe_opcode_t));

	} else {

		addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t));

	}

	/* Check we're not actually recursing */

	if (kprobe_running()) {

		p = get_kprobe(addr);
@@ -579,6 +569,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	if (args->regs && user_mode(args->regs))

		return ret;



	switch (val) {

	case DIE_INT3:

		if (kprobe_handler(args->regs))

arch/ia64/kernel/kprobes.c

+3 −0
Original line number Diff line number Diff line
@@ -740,6 +740,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	if (args->regs && user_mode(args->regs))

		return ret;



	switch(val) {

	case DIE_BREAK:

		/* err is break number from ia64_bad_break() */

arch/powerpc/kernel/kprobes.c

+3 −0
Original line number Diff line number Diff line
@@ -396,6 +396,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	if (args->regs && user_mode(args->regs))

		return ret;



	switch (val) {

	case DIE_BPT:

		if (kprobe_handler(args->regs))

arch/sparc64/kernel/kprobes.c

+3 −0
Original line number Diff line number Diff line
@@ -324,6 +324,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	if (args->regs && user_mode(args->regs))

		return ret;



	switch (val) {

	case DIE_DEBUG:

		if (kprobe_handler(args->regs))

arch/x86_64/kernel/kprobes.c

+3 −0
Original line number Diff line number Diff line
@@ -601,6 +601,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	struct die_args *args = (struct die_args *)data;

	int ret = NOTIFY_DONE;



	if (args->regs && user_mode(args->regs))

		return ret;



	switch (val) {

	case DIE_INT3:

		if (kprobe_handler(args->regs))

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