signal: turn dequeue_signal_lock() into kernel_dequeue_signal()

1. Rename dequeue_signal_lock() to kernel_dequeue_signal(). This
   matches another "for kthreads only" kernel_sigaction() helper.

2. Remove the "tsk" and "mask" arguments, they are always current
   and current->blocked. And it is simply wrong if tsk != current.

3. We could also remove the 3rd "siginfo_t *info" arg but it looks
   potentially useful. However we can simplify the callers if we
   change kernel_dequeue_signal() to accept info => NULL.

4. Remove _irqsave, it is never called from atomic context.

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>
This commit is contained in:
Oleg Nesterov 2015-11-06 16:32:22 -08:00 committed by Linus Torvalds
parent 2e01fabe67
commit be0e6f290f
4 changed files with 12 additions and 21 deletions

View File

@ -444,9 +444,7 @@ static int nbd_thread_recv(struct nbd_device *nbd)
spin_unlock_irqrestore(&nbd->tasks_lock, flags);
if (signal_pending(current)) {
siginfo_t info;
ret = dequeue_signal_lock(current, &current->blocked, &info);
ret = kernel_dequeue_signal(NULL);
dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n",
task_pid_nr(current), current->comm, ret);
mutex_lock(&nbd->tx_lock);
@ -560,11 +558,8 @@ static int nbd_thread_send(void *data)
!list_empty(&nbd->waiting_queue));
if (signal_pending(current)) {
siginfo_t info;
int ret;
int ret = kernel_dequeue_signal(NULL);
ret = dequeue_signal_lock(current, &current->blocked,
&info);
dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n",
task_pid_nr(current), current->comm, ret);
mutex_lock(&nbd->tx_lock);
@ -592,10 +587,8 @@ static int nbd_thread_send(void *data)
spin_unlock_irqrestore(&nbd->tasks_lock, flags);
/* Clear maybe pending signals */
if (signal_pending(current)) {
siginfo_t info;
dequeue_signal_lock(current, &current->blocked, &info);
}
if (signal_pending(current))
kernel_dequeue_signal(NULL);
return 0;
}

View File

@ -2345,7 +2345,6 @@ static void fsg_disable(struct usb_function *f)
static void handle_exception(struct fsg_common *common)
{
siginfo_t info;
int i;
struct fsg_buffhd *bh;
enum fsg_state old_state;
@ -2357,8 +2356,7 @@ static void handle_exception(struct fsg_common *common)
* into a high-priority EXIT exception.
*/
for (;;) {
int sig =
dequeue_signal_lock(current, &current->blocked, &info);
int sig = kernel_dequeue_signal(NULL);
if (!sig)
break;
if (sig != SIGUSR1) {

View File

@ -121,13 +121,12 @@ static int jffs2_garbage_collect_thread(void *_c)
/* Put_super will send a SIGKILL and then wait on the sem.
*/
while (signal_pending(current) || freezing(current)) {
siginfo_t info;
unsigned long signr;
if (try_to_freeze())
goto again;
signr = dequeue_signal_lock(current, &current->blocked, &info);
signr = kernel_dequeue_signal(NULL);
switch(signr) {
case SIGSTOP:

View File

@ -2462,14 +2462,15 @@ extern void ignore_signals(struct task_struct *);
extern void flush_signal_handlers(struct task_struct *, int force_default);
extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
static inline int kernel_dequeue_signal(siginfo_t *info)
{
unsigned long flags;
struct task_struct *tsk = current;
siginfo_t __info;
int ret;
spin_lock_irqsave(&tsk->sighand->siglock, flags);
ret = dequeue_signal(tsk, mask, info);
spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
spin_lock_irq(&tsk->sighand->siglock);
ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
spin_unlock_irq(&tsk->sighand->siglock);
return ret;
}