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From: Gabriel Krisman Bertazi <krisman@suse.de>
To: axboe@kernel.dk
Cc: io-uring@vger.kernel.org
Subject: Re: [PATCH liburing 1/2] test/send_recvmsg: Preserve msghdr until op_recvmsg completes
Date: Wed, 22 Jul 2026 14:24:55 -0400	[thread overview]
Message-ID: <87ik66evbc.fsf@mailhost.krisman.be> (raw)
In-Reply-To: <20260722181710.79099-2-krisman@suse.de>

Gabriel Krisman Bertazi <krisman@suse.de> writes:

> msghdr is allocated on the stack at recv_prep, which means it may go out
> of scope before the kernel has a chance to complete the operation.  This
> results in spurious test failures when we reach far enough into recv_fn
> to reuse the stack space before op_recvmsg executes.  I found it easily
> reproducible when compiling with '-O0 -g3' to avoid gcc from optimizing
> further local variables out of the stack.

In hindsight, I should clarify that by 'test failure' I mean a
segmentation fault in the testcase, not a T_EXIT_FAIL. Should have put
that in the commit message.

-- 
Gabriel Krisman Bertazi

  reply	other threads:[~2026-07-22 18:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-22 18:17 [PATCH liburing 0/2] Fix op_recv stack corruption Gabriel Krisman Bertazi
2026-07-22 18:17 ` [PATCH liburing 1/2] test/send_recvmsg: Preserve msghdr until op_recvmsg completes Gabriel Krisman Bertazi
2026-07-22 18:24   ` Gabriel Krisman Bertazi [this message]
2026-07-22 19:21   ` Jens Axboe
2026-07-22 20:00     ` Gabriel Krisman Bertazi
2026-07-22 20:33       ` Gabriel Krisman Bertazi
2026-07-22 18:17 ` [PATCH liburing 2/2] test/recv-msgall-stream: " Gabriel Krisman Bertazi

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