From: Jens Axboe <axboe@kernel.dk>
Date: Mon, 9 Nov 2020 14:19:32 +0000 (-0700)
Subject: Merge tag 'core-entry-notify-signal' of git://git.kernel.org/pub/scm/linux/kernel... 
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=29701d69b98d0a132abd63fe2e51125f478fbc53;p=linux.git

Merge tag 'core-entry-notify-signal' of git://git./linux/kernel/git/tip/tip into tif-task_work.arch

Core changes to support TASK_NOTIFY_SIGNAL

* tag 'core-entry-notify-signal' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  task_work: Use TIF_NOTIFY_SIGNAL if available
  entry: Add support for TIF_NOTIFY_SIGNAL
  signal: Add task_sigpending() helper
---

29701d69b98d0a132abd63fe2e51125f478fbc53
diff --cc include/linux/entry-common.h
index 474f29638d2c9,c7bfac45f9516..b9711e813ec2d
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@@ -37,8 -37,12 +37,12 @@@
  # define _TIF_UPROBE			(0)
  #endif
  
+ #ifndef _TIF_NOTIFY_SIGNAL
+ # define _TIF_NOTIFY_SIGNAL		(0)
+ #endif
+ 
  /*
 - * TIF flags handled in syscall_enter_from_usermode()
 + * TIF flags handled in syscall_enter_from_user_mode()
   */
  #ifndef ARCH_SYSCALL_ENTER_WORK
  # define ARCH_SYSCALL_ENTER_WORK	(0)
diff --cc kernel/entry/common.c
index e9e2df3f3f9ee,42eff115c4269..33bb5f9f399cd
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@@ -157,10 -139,11 +165,10 @@@ static unsigned long exit_to_user_mode_
  		if (ti_work & _TIF_PATCH_PENDING)
  			klp_update_patch_state(current);
  
- 		if (ti_work & _TIF_SIGPENDING)
- 			arch_do_signal(regs);
+ 		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+ 			handle_signal_work(regs, ti_work);
  
  		if (ti_work & _TIF_NOTIFY_RESUME) {
 -			clear_thread_flag(TIF_NOTIFY_RESUME);
  			tracehook_notify_resume(regs);
  			rseq_handle_notify_resume(NULL, regs);
  		}
diff --cc kernel/task_work.c
index 8d6e1217c451c,ae058893913ce..15b087286bea4
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@@ -29,11 -52,10 +57,10 @@@ static void task_work_notify_signal(str
   * RETURNS:
   * 0 if succeeds or -ESRCH.
   */
 -int
 -task_work_add(struct task_struct *task, struct callback_head *work, int notify)
 +int task_work_add(struct task_struct *task, struct callback_head *work,
 +		  enum task_work_notify_mode notify)
  {
  	struct callback_head *head;
- 	unsigned long flags;
  
  	do {
  		head = READ_ONCE(task->task_works);
@@@ -49,21 -69,8 +76,11 @@@
  		set_notify_resume(task);
  		break;
  	case TWA_SIGNAL:
- 		/*
- 		 * Only grab the sighand lock if we don't already have some
- 		 * task_work pending. This pairs with the smp_store_mb()
- 		 * in get_signal(), see comment there.
- 		 */
- 		if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) &&
- 		    lock_task_sighand(task, &flags)) {
- 			task->jobctl |= JOBCTL_TASK_WORK;
- 			signal_wake_up(task, 0);
- 			unlock_task_sighand(task, &flags);
- 		}
+ 		task_work_notify_signal(task);
  		break;
 +	default:
 +		WARN_ON_ONCE(1);
 +		break;
  	}
  
  	return 0;