2010-08-22 10:22:42

by Namhyung Kim

Subject: [PATCH 3/3] ptrace: annotate siglock acquirement

lock_task_sighand() conditionally acquires sighand->siglock in case of
returning non-NULL but unlock_task_sighand() releases it unconditionally.
This leads sparse to complain about the lock context imbalance. Annotate it
to make sparse happier.

Signed-off-by: Namhyung Kim <[email protected]>
---
kernel/ptrace.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1abbb4d..4553275 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -438,6 +438,7 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
int error = -ESRCH;

if (lock_task_sighand(child, &flags)) {
+ __acquire(&child->sighand->siglock);
error = -EINVAL;
if (likely(child->last_siginfo != NULL)) {
*info = *child->last_siginfo;
@@ -454,6 +455,7 @@ static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
int error = -ESRCH;

if (lock_task_sighand(child, &flags)) {
+ __acquire(&child->sighand->siglock);
error = -EINVAL;
if (likely(child->last_siginfo != NULL)) {
*child->last_siginfo = *info;
--
1.7.0.4

2010-08-23 16:53:43

by Roland McGrath

Subject: Re: [PATCH 3/3] ptrace: annotate siglock acquirement

Acked-by: Roland McGrath <[email protected]>