perf: Use new infrastructure to fix deadlocks in execve (69143038) · Commits · 戴 / test

kernel/events/core.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -1249,7 +1249,7 @@ static void put_ctx(struct perf_event_context *ctx)
		* function.
		*
		* Lock order:
		* cred_guard_mutex
		* exec_update_mutex
		* task_struct::perf_event_mutex
		* perf_event_context::mutex
		* perf_event::child_mutex;
		@@ -11263,14 +11263,14 @@ SYSCALL_DEFINE5(perf_event_open,
		}

		if (task) {
		err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
		err = mutex_lock_interruptible(&task->signal->exec_update_mutex);
		if (err)
		goto err_task;

		/*
		* Reuse ptrace permission checks for now.
		*
		* We must hold cred_guard_mutex across this and any potential
		* We must hold exec_update_mutex across this and any potential
		* perf_install_in_context() call for this new event to
		* serialize against exec() altering our credentials (and the
		* perf_event_exit_task() that could imply).
		@@ -11559,7 +11559,7 @@ SYSCALL_DEFINE5(perf_event_open,
		mutex_unlock(&ctx->mutex);

		if (task) {
		mutex_unlock(&task->signal->cred_guard_mutex);
		mutex_unlock(&task->signal->exec_update_mutex);
		put_task_struct(task);
		}

		@@ -11595,7 +11595,7 @@ err_alloc:
		free_event(event);
		err_cred:
		if (task)
		mutex_unlock(&task->signal->cred_guard_mutex);
		mutex_unlock(&task->signal->exec_update_mutex);
		err_task:
		if (task)
		put_task_struct(task);
		@@ -11900,7 +11900,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
		/*
		* When a child task exits, feed back event values to parent events.
		*
		* Can be called with cred_guard_mutex held when called from
		* Can be called with exec_update_mutex held when called from
		* install_exec_creds().
		*/
		void perf_event_exit_task(struct task_struct *child)

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