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| author | Oleg Nesterov <oleg@redhat.com> | 2015-11-07 03:32:25 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-07 04:50:42 +0300 |
| commit | 9a13049e83f346cb1cbd60c64e520a73c396af16 (patch) | |
| tree | 11a2ac2ac28dbfa477d5b4f1e14a2173b4867a8f | |
| parent | be0e6f290f78b84a3b21b8c8c46819c4514fe632 (diff) | |
| download | linux-9a13049e83f346cb1cbd60c64e520a73c396af16.tar.xz | |
signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
jffs2_garbage_collect_thread() can race with SIGCONT and sleep in
TASK_STOPPED state after it was already sent. Add the new helper,
kernel_signal_stop(), which does this correctly.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/jffs2/background.c | 3 | ||||
| -rw-r--r-- | include/linux/sched.h | 10 |
2 files changed, 11 insertions, 2 deletions
diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c index f3145fd86d86..53cc7350af33 100644 --- a/fs/jffs2/background.c +++ b/fs/jffs2/background.c @@ -132,8 +132,7 @@ static int jffs2_garbage_collect_thread(void *_c) case SIGSTOP: jffs2_dbg(1, "%s(): SIGSTOP received\n", __func__); - set_current_state(TASK_STOPPED); - schedule(); + kernel_signal_stop(); break; case SIGKILL: diff --git a/include/linux/sched.h b/include/linux/sched.h index 3d54924b4b86..4069febaa34a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2475,6 +2475,16 @@ static inline int kernel_dequeue_signal(siginfo_t *info) return ret; } +static inline void kernel_signal_stop(void) +{ + spin_lock_irq(¤t->sighand->siglock); + if (current->jobctl & JOBCTL_STOP_DEQUEUED) + __set_current_state(TASK_STOPPED); + spin_unlock_irq(¤t->sighand->siglock); + + schedule(); +} + extern void release_task(struct task_struct * p); extern int send_sig_info(int, struct siginfo *, struct task_struct *); extern int force_sigsegv(int, struct task_struct *); |