From: Stefan Metzmacher <[email protected]>
To: [email protected]
Cc: Stefan Metzmacher <[email protected]>, Jens Axboe <[email protected]>
Subject: [PATCH v2 1/5] kernel: always initialize task->pf_io_worker to NULL
Date: Sat, 20 Mar 2021 01:00:27 +0100 [thread overview]
Message-ID: <438b738c1e4827a7fdfe43087da88bbe17eedc72.1616197787.git.metze@samba.org> (raw)
In-Reply-To: <[email protected]>
Otherwise io_wq_worker_{running,sleeping}() may dereference an
invalid pointer (in future). Currently all users of create_io_thread()
are fine and get task->pf_io_worker = NULL implicitly from the
wq_manager, which got it either from the userspace thread
of the sq_thread, which explicitly reset it to NULL.
I think it's safer to always reset it in order to avoid future
problems.
Fixes: 3bfe6106693b ("io-wq: fork worker threads from original task")
cc: Jens Axboe <[email protected]>
Signed-off-by: Stefan Metzmacher <[email protected]>
---
kernel/fork.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/fork.c b/kernel/fork.c
index d3171e8e88e5..0b7068c55552 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -927,6 +927,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
tsk->splice_pipe = NULL;
tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
+ tsk->pf_io_worker = NULL;
account_kernel_stack(tsk, 1);
--
2.25.1
next prev parent reply other threads:[~2021-03-20 0:01 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 23:27 Problems with io_threads Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 00/10] Complete setup before calling wake_up_new_task() and improve task->comm Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 01/10] kernel: always initialize task->pf_io_worker to NULL Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 02/10] io_uring: io_sq_thread() no longer needs to reset current->pf_io_worker Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 03/10] io-wq: call set_task_comm() before wake_up_new_task() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 04/10] io_uring: complete sq_thread setup before calling wake_up_new_task() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 05/10] io-wq: protect against future set_task_comm() overflows Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 06/10] io_uring: " Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 07/10] fs/proc: hide PF_IO_WORKER in get_task_cmdline() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 08/10] fs/proc: protect /proc/<pid>/[task/<tid>]/comm for PF_IO_WORKER Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 09/10] io-wq: add io_wq_worker_comm() helper function for dynamic proc_task_comm() generation Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 10/10] fs/proc: make use of io_wq_worker_comm() for PF_IO_WORKER threads Stefan Metzmacher
2021-03-17 22:42 ` [RFC PATCH 00/10] Complete setup before calling wake_up_new_task() and improve task->comm Jens Axboe
2021-03-17 23:06 ` Stefan Metzmacher
2021-03-17 23:26 ` Jens Axboe
2021-03-20 0:00 ` [PATCH v2 0/5] " Stefan Metzmacher
2021-03-20 0:00 ` Stefan Metzmacher [this message]
2021-03-20 0:00 ` [PATCH v2 2/5] io_uring: io_sq_thread() no longer needs to reset current->pf_io_worker Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 3/5] io-wq: call set_task_comm() before wake_up_new_task() Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 4/5] io_uring: complete sq_thread setup before calling wake_up_new_task() Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 5/5] fs/proc: hide PF_IO_WORKER in get_task_cmdline() Stefan Metzmacher
2021-03-20 1:24 ` [PATCH v2 0/5] Complete setup before calling wake_up_new_task() and improve task->comm Jens Axboe
2021-03-20 19:22 ` Stefan Metzmacher
2021-03-20 22:39 ` Jens Axboe
2021-03-19 23:46 ` Problems with io_threads Jens Axboe
2021-03-20 0:25 ` Stefan Metzmacher
2021-03-20 1:20 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=438b738c1e4827a7fdfe43087da88bbe17eedc72.1616197787.git.metze@samba.org \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox