From: Bernd Edlinger <bernd.edlinger@hotmail.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Christian Brauner <christian.brauner@ubuntu.com>,
Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Oleg Nesterov <oleg@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Andrei Vagin <avagin@gmail.com>, Ingo Molnar <mingo@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Yuyang Du <duyuyang@gmail.com>,
David Hildenbrand <david@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Anshuman Khandual <anshuman.khandual@arm.com>,
David Howells <dhowells@redhat.com>,
James Morris <jamorris@linux.microsoft.com>,
Shakeel Butt <shakeelb@google.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
Christian Kellner <christian@kellner.me>,
Andrea Arcangeli <aarcange@redhat.com>,
Aleksa Sarai <cyphar@cyphar.com>,
"Dmitry V. Levin" <ldv@altlinux.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>
Subject: [PATCH v6 13/16] perf: Use new infrastructure to fix deadlocks in execve
Date: Fri, 20 Mar 2020 21:27:55 +0100 [thread overview]
Message-ID: <AM6PR03MB51704A188C3A1FA02B76B9EFE4F50@AM6PR03MB5170.eurprd03.prod.outlook.com> (raw)
In-Reply-To: <077b63b7-6f5e-aa8e-bf96-a586b481cc46@hotmail.de>
This changes perf_event_set_clock to use the new exec_update_mutex
instead of cred_guard_mutex.
This should be safe, as the credentials are only used for reading.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
---
kernel/events/core.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e453589..71cba8c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
}
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 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
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 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
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)
--
1.9.1
next prev parent reply other threads:[~2020-03-20 20:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <077b63b7-6f5e-aa8e-bf96-a586b481cc46@hotmail.de>
2020-03-20 20:24 ` [PATCH v6 01/16] exec: Only compute current once in flush_old_exec Bernd Edlinger
2020-03-20 20:24 ` [PATCH v6 02/16] exec: Factor unshare_sighand out of de_thread and call it separately Bernd Edlinger
2020-03-20 20:25 ` [PATCH v6 03/16] exec: Move cleanup of posix timers on exec out of de_thread Bernd Edlinger
2020-03-20 20:25 ` [PATCH v6 04/16] exec: Move exec_mmap right after de_thread in flush_old_exec Bernd Edlinger
2020-03-20 20:25 ` [PATCH v6 05/16] exec: Add exec_update_mutex to replace cred_guard_mutex Bernd Edlinger
2020-03-23 10:51 ` Kirill Tkhai
2020-03-20 20:26 ` [PATCH v6 06/16] exec: Fix a deadlock in strace Bernd Edlinger
2020-03-20 20:26 ` [PATCH v6 07/16] selftests/ptrace: add test cases for dead-locks Bernd Edlinger
2020-03-20 20:26 ` [PATCH v6 08/16] mm: docs: Fix a comment in process_vm_rw_core Bernd Edlinger
2020-03-20 20:26 ` [PATCH v6 09/16] kernel: doc: remove outdated comment cred.c Bernd Edlinger
2020-03-20 20:27 ` [PATCH v6 10/16] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve Bernd Edlinger
2020-03-25 15:41 ` Christian Brauner
2020-03-20 20:27 ` [PATCH v6 11/16] proc: " Bernd Edlinger
2020-03-20 20:27 ` [PATCH v6 12/16] proc: io_accounting: " Bernd Edlinger
2020-03-20 20:27 ` Bernd Edlinger [this message]
2020-03-21 2:46 ` [PATCH v6 14/16] pidfd: " Bernd Edlinger
2020-03-25 15:40 ` Christian Brauner
2020-03-21 2:46 ` [PATCH v6 15/16] exec: Fix dead-lock in de_thread with ptrace_attach Bernd Edlinger
2020-03-25 14:27 ` Eric W. Biederman
2020-03-29 4:31 ` Bernd Edlinger
2020-03-29 6:36 ` Bernd Edlinger
2020-03-30 18:26 ` [PATCH v7 " Bernd Edlinger
2020-03-21 2:47 ` [PATCH v6 16/16] doc: Update documentation of ->exec_*_mutex Bernd Edlinger
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