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Kprobes IA64 check jprobe break before handling
- From: Keshavamurthy Anil S <anil dot s dot keshavamurthy at intel dot com>
- To: akpm at osdl dot org
- Cc: Linux Kernel <linux-kernel at vger dot kernel dot org>, linux-ia64 at vger dot kernel dot org, anil dot s dot keshavamurthy at intel dot com, Rusty Lynch <rusty dot lynch at intel dot com>, systemtap at sources dot redhat dot com
- Date: Thu, 26 May 2005 14:25:39 -0700
- Subject: Kprobes IA64 check jprobe break before handling
- Reply-to: Keshavamurthy Anil S <anil dot s dot keshavamurthy at intel dot com>
From: anil.s.keshavamurthy@intel.com
Subject: Kprobes IA64 check jprobe break before handling
Once the jprobe instrumented function returns, it executes
a jprobe_break which is a break instruction with
__IA64_JPROBE_BREAK value. The current patch checks for
this break value, before assuming that jprobe
instrumented function just completed.
The previous code was not checking for this value and
that was a bug.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
===================================================================
arch/ia64/kernel/kprobes.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
Index: linux-2.6.12-rc5/arch/ia64/kernel/kprobes.c
===================================================================
--- linux-2.6.12-rc5.orig/arch/ia64/kernel/kprobes.c
+++ linux-2.6.12-rc5/arch/ia64/kernel/kprobes.c
@@ -284,10 +284,11 @@ static void prepare_ss(struct kprobe *p,
ia64_psr(regs)->ss = 1;
}
-static int pre_kprobes_handler(struct pt_regs *regs)
+static int pre_kprobes_handler(struct die_args *args)
{
struct kprobe *p;
int ret = 0;
+ struct pt_regs *regs = args->regs;
kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
preempt_disable();
@@ -302,7 +303,7 @@ static int pre_kprobes_handler(struct pt
}
arch_disarm_kprobe(p);
ret = 1;
- } else {
+ } else if (args->err == __IA64_BREAK_JPROBE) {
/*
* jprobe instrumented function just completed
*/
@@ -310,6 +311,9 @@ static int pre_kprobes_handler(struct pt
if (p->break_handler && p->break_handler(p, regs)) {
goto ss_probe;
}
+ } else {
+ /* Not our break */
+ goto no_kprobe;
}
}
@@ -380,7 +384,7 @@ int kprobe_exceptions_notify(struct noti
struct die_args *args = (struct die_args *)data;
switch(val) {
case DIE_BREAK:
- if (pre_kprobes_handler(args->regs))
+ if (pre_kprobes_handler(args))
return NOTIFY_STOP;
break;
case DIE_SS: