[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 <shaohua.li@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 90518e4..fc4d267 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -435,6 +435,23 @@
/* 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 */
+ continue;
+
if (ri->rp && ri->rp->handler)
ri->rp->handler(ri, regs);
@@ -452,8 +469,6 @@
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();