Commit 2326c770 authored by bibo,mao's avatar bibo,mao Committed by Linus Torvalds

[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
......@@ -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))
......
......@@ -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() */
......
......@@ -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))
......
......@@ -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))
......
......@@ -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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