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yaml
---
r: 323822
b: refs/heads/master
c: c6aaf4d
h: refs/heads/master
v: v3
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Masami Hiramatsu authored and Steven Rostedt committed Sep 14, 2012
1 parent 71c1cc5 commit 55ce2d9
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Showing 3 changed files with 30 additions and 17 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 47d5a5f88b9d25d6464c9b60c28f391e84e3ed65
refs/heads/master: c6aaf4d0bb86e2154ea31a33804cec300611255f
42 changes: 29 additions & 13 deletions trunk/arch/x86/kernel/kprobes.c
Original file line number Diff line number Diff line change
Expand Up @@ -541,6 +541,8 @@ reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb
return 1;
}

static void __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb);
/*
* Interrupts are disabled on entry as trap3 is an interrupt gate and they
* remain disabled throughout this function.
Expand Down Expand Up @@ -599,6 +601,12 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
} else if (kprobe_running()) {
p = __this_cpu_read(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
#ifdef KPROBES_CAN_USE_FTRACE
if (kprobe_ftrace(p)) {
skip_singlestep(p, regs, kcb);
return 1;
}
#endif
setup_singlestep(p, regs, kcb, 0);
return 1;
}
Expand Down Expand Up @@ -1053,6 +1061,21 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
}

#ifdef KPROBES_CAN_USE_FTRACE
static void __kprobes skip_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb)
{
/*
* Emulate singlestep (and also recover regs->ip)
* as if there is a 5byte nop
*/
regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
if (unlikely(p->post_handler)) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
}
__this_cpu_write(current_kprobe, NULL);
}

/* Ftrace callback handler for kprobes */
void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct pt_regs *regs)
Expand All @@ -1077,19 +1100,12 @@ void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,

__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (p->pre_handler)
p->pre_handler(p, regs);

if (unlikely(p->post_handler)) {
/*
* Emulate singlestep (and also recover regs->ip)
* as if there is a 5byte nop
*/
regs->ip = ip + MCOUNT_INSN_SIZE;
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
}
__this_cpu_write(current_kprobe, NULL);
if (!p->pre_handler || !p->pre_handler(p, regs))
skip_singlestep(p, regs, kcb);
/*
* If pre_handler returns !0, it sets regs->ip and
* resets current kprobe.
*/
}
end:
local_irq_restore(flags);
Expand Down
3 changes: 0 additions & 3 deletions trunk/kernel/kprobes.c
Original file line number Diff line number Diff line change
Expand Up @@ -1418,9 +1418,6 @@ static __kprobes int check_kprobe_address_safe(struct kprobe *p,
/* Given address is not on the instruction boundary */
if ((unsigned long)p->addr != ftrace_addr)
return -EILSEQ;
/* break_handler (jprobe) can not work with ftrace */
if (p->break_handler)
return -EINVAL;
p->flags |= KPROBE_FLAG_FTRACE;
#else /* !KPROBES_CAN_USE_FTRACE */
return -EINVAL;
Expand Down

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