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authorOleg Nesterov <oleg@tv-sign.ru>2008-07-25 01:47:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:39 -0700
commit3d749b9e676b26584a47e75c235aa6f69d0697ae (patch)
tree2db2dab84cde07c4872ac5e8d4078f2a3fc4271d /kernel
parent364d3c13c17f45da6d638011078d4c4d3070d719 (diff)
downloadlinux-2.6.34-ux500-3d749b9e676b26584a47e75c235aa6f69d0697ae.tar.gz
ptrace: simplify ptrace_stop()->sigkill_pending() path
1. SIGKILL can't be blocked, remove this check from sigkill_pending(). 2. When ptrace_stop() sees sigkill_pending() == T, it can just return. Kill "int killed" and simplify the code. This also is more correct, the tracer shouldn't see us in TASK_TRACED if we are not going to stop. I strongly believe this code needs further changes. We should do the "was this task killed" check unconditionally, currently it depends on arch_ptrace_stop_needed(). On the other hand, sigkill_pending() isn't very clever. If the task was killed tkill(SIGKILL), the signal can be already dequeued if the caller is do_exit(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/signal.c12
1 files changed, 5 insertions, 7 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index fdab7b363fa..39c1706edf0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1496,9 +1496,8 @@ static inline int may_ptrace_stop(void)
*/
static int sigkill_pending(struct task_struct *tsk)
{
- return ((sigismember(&tsk->pending.signal, SIGKILL) ||
- sigismember(&tsk->signal->shared_pending.signal, SIGKILL)) &&
- !unlikely(sigismember(&tsk->blocked, SIGKILL)));
+ return sigismember(&tsk->pending.signal, SIGKILL) ||
+ sigismember(&tsk->signal->shared_pending.signal, SIGKILL);
}
/*
@@ -1514,8 +1513,6 @@ static int sigkill_pending(struct task_struct *tsk)
*/
static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
{
- int killed = 0;
-
if (arch_ptrace_stop_needed(exit_code, info)) {
/*
* The arch code has something special to do before a
@@ -1531,7 +1528,8 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
spin_unlock_irq(&current->sighand->siglock);
arch_ptrace_stop(exit_code, info);
spin_lock_irq(&current->sighand->siglock);
- killed = sigkill_pending(current);
+ if (sigkill_pending(current))
+ return;
}
/*
@@ -1548,7 +1546,7 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
__set_current_state(TASK_TRACED);
spin_unlock_irq(&current->sighand->siglock);
read_lock(&tasklist_lock);
- if (!unlikely(killed) && may_ptrace_stop()) {
+ if (may_ptrace_stop()) {
do_notify_parent_cldstop(current, CLD_TRAPPED);
read_unlock(&tasklist_lock);
schedule();