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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2010-11-10 10:05:58 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-11-10 10:05:54 +0100
commit89480801a17a3069f45169d40b828c8e511aa005 (patch)
treeb2318335080bede28fbe107de5a5b67cc74b4918 /arch/s390/kernel
parentadb45839817392102e659c19e5c19aa39530021f (diff)
downloadlinux-linaro-android-89480801a17a3069f45169d40b828c8e511aa005.tar.gz
[S390] kprobes: Fix the return address of multiple kretprobes
Analog to git commit 737480a0d525dae13306296da08029dff545bc72 fix the return address of subsequent kretprobes when multiple kretprobes are set on the same function. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/kprobes.c29
1 files changed, 26 insertions, 3 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 70cf73bdba2..2564793ec2b 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -349,6 +349,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
struct hlist_node *node, *tmp;
unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
+ kprobe_opcode_t *correct_ret_addr = NULL;
INIT_HLIST_HEAD(&empty_rp);
kretprobe_hash_lock(current, &head, &flags);
@@ -371,10 +372,32 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
/* another task is sharing our hash bucket */
continue;
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
+ 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;
+ }
+
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+ correct_ret_addr = ri->ret_addr;
+ 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 (ri->rp && ri->rp->handler) {
+ ri->ret_addr = correct_ret_addr;
+ ri->rp->handler(ri, regs);
+ }
+
recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address) {
@@ -386,7 +409,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
break;
}
}
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
reset_current_kprobe();