From 3661999a17b0397c7a93c200b280c55958ba3593 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 13 Nov 2007 14:55:20 +0800 Subject: [PATCH] [IA64] kprobe: make kreturn probe handler stack unwind correct Restore regs->ccr_iip before kreturn probe handler runs. In this way, if probe handler does unwind, unwind can correctly get the stack trace. Fixes: http://sourceware.org/bugzilla/show_bug.cgi?id=5051 Signed-off-by: Shaohua Li Signed-off-by: Tony Luck --- arch/ia64/kernel/kprobes.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 90518e43aba0..fc4d2676264f 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -430,6 +430,23 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) * real return address, and all the rest will point to * kretprobe_trampoline */ + hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { + if (ri->task != current) + /* another task is sharing our hash bucket */ + continue; + + orig_ret_address = (unsigned long)ri->ret_addr; + if (orig_ret_address != trampoline_address) + /* + * This is the real return address. Any other + * instances associated with this task are for + * other calls deeper on the call stack + */ + break; + } + + regs->cr_iip = orig_ret_address; + hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task != current) /* another task is sharing our hash bucket */ @@ -452,8 +469,6 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) kretprobe_assert(ri, orig_ret_address, trampoline_address); - regs->cr_iip = orig_ret_address; - reset_current_kprobe(); spin_unlock_irqrestore(&kretprobe_lock, flags); preempt_enable_no_resched();