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authorPeter Zijlstra <peterz@infradead.org>2021-06-11 10:28:17 +0200
committerPeter Zijlstra <peterz@infradead.org>2021-06-18 11:43:09 +0200
commit2f064a59a11ff9bc22e52e9678bc601404c7cb34 (patch)
treeacc246021cd9f158016247f00f238668963daed7 /kernel/ptrace.c
parent7c3edd6d9cb4d8ea8db5b167dc2eee94d7e4667b (diff)
downloadlinux-2f064a59a11ff9bc22e52e9678bc601404c7cb34.tar.gz
sched: Change task_struct::state
Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_ONCE/WRITE_ONCE as appropriate.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
Diffstat (limited to 'kernel/ptrace.c')
-rw-r--r--kernel/ptrace.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 2997ca600d18..f8589bf8d7dc 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -197,7 +197,7 @@ static bool ptrace_freeze_traced(struct task_struct *task)
 	spin_lock_irq(&task->sighand->siglock);
 	if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
 	    !__fatal_signal_pending(task)) {
-		task->state = __TASK_TRACED;
+		WRITE_ONCE(task->__state, __TASK_TRACED);
 		ret = true;
 	}
 	spin_unlock_irq(&task->sighand->siglock);
@@ -207,7 +207,7 @@ static bool ptrace_freeze_traced(struct task_struct *task)
 
 static void ptrace_unfreeze_traced(struct task_struct *task)
 {
-	if (task->state != __TASK_TRACED)
+	if (READ_ONCE(task->__state) != __TASK_TRACED)
 		return;
 
 	WARN_ON(!task->ptrace || task->parent != current);
@@ -217,11 +217,11 @@ static void ptrace_unfreeze_traced(struct task_struct *task)
 	 * Recheck state under the lock to close this race.
 	 */
 	spin_lock_irq(&task->sighand->siglock);
-	if (task->state == __TASK_TRACED) {
+	if (READ_ONCE(task->__state) == __TASK_TRACED) {
 		if (__fatal_signal_pending(task))
 			wake_up_state(task, __TASK_TRACED);
 		else
-			task->state = TASK_TRACED;
+			WRITE_ONCE(task->__state, TASK_TRACED);
 	}
 	spin_unlock_irq(&task->sighand->siglock);
 }
@@ -256,7 +256,7 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
 	 */
 	read_lock(&tasklist_lock);
 	if (child->ptrace && child->parent == current) {
-		WARN_ON(child->state == __TASK_TRACED);
+		WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
 		/*
 		 * child->sighand can't be NULL, release_task()
 		 * does ptrace_unlink() before __exit_signal().
@@ -273,7 +273,7 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
 			 * ptrace_stop() changes ->state back to TASK_RUNNING,
 			 * so we should not worry about leaking __TASK_TRACED.
 			 */
-			WARN_ON(child->state == __TASK_TRACED);
+			WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
 			ret = -ESRCH;
 		}
 	}