[PATCH 14/19] ptrace: restructure ptrace_getsiginfo()

From: Tejun Heo
Date: Tue May 24 2011 - 14:38:20 EST


Flatten ptrace_getsiginfo() to prepare for more logic in the success
path. While at it, remove [un]likely() on child->last_siginfo check -
signal delivery and group stop traps can only be distinguished by NULL
siginfo and group stop isn't that unlikely.

This patch doesn't introduce any functional change.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/ptrace.c | 21 ++++++++++++---------
1 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 3911567..851870c 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -572,16 +572,19 @@ static int ptrace_setoptions(struct task_struct *child, unsigned long data)
static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
{
unsigned long flags;
- int error = -ESRCH;
+ int error;

- if (lock_task_sighand(child, &flags)) {
- error = -EINVAL;
- if (likely(child->last_siginfo != NULL)) {
- *info = *child->last_siginfo;
- error = 0;
- }
- unlock_task_sighand(child, &flags);
- }
+ if (!lock_task_sighand(child, &flags))
+ return -ESRCH;
+
+ error = -EINVAL;
+ if (!child->last_siginfo)
+ goto out_unlock;
+
+ error = 0;
+ *info = *child->last_siginfo;
+out_unlock:
+ unlock_task_sighand(child, &flags);
return error;
}

--
1.7.1

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