From: Peter Xu <peterx@redhat.com>
To: Fabiano Rosas <farosas@suse.de>
Cc: qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>,
Wei Wang <wei.w.wang@intel.com>,
Leonardo Bras <leobras@redhat.com>
Subject: Re: [PATCH v4 2/8] migration: Fix possible races when shutting down the return path
Date: Wed, 16 Aug 2023 11:05:59 -0400 [thread overview]
Message-ID: <ZNzl1xXksUEex+OP@x1n> (raw)
In-Reply-To: <20230816142510.5637-3-farosas@suse.de>
On Wed, Aug 16, 2023 at 11:25:04AM -0300, Fabiano Rosas wrote:
> We cannot call qemu_file_shutdown() on the return path file without
> taking the file lock. The return path thread could be running it's
> cleanup code and have just cleared the from_dst_file pointer.
>
> Checking ms->to_dst_file for errors could also race with
> migrate_fd_cleanup() which clears the to_dst_file pointer.
>
> Protect both accesses by taking the file lock.
>
> This was caught by inspection, it should be rare, but the next patches
> will start calling this code from other places, so let's do the
> correct thing.
>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
next prev parent reply other threads:[~2023-08-16 15:06 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-16 14:25 [PATCH v4 0/8] Fix segfault on migration return path Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 1/8] migration: Fix possible race when setting rp_state.error Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 2/8] migration: Fix possible races when shutting down the return path Fabiano Rosas
2023-08-16 15:05 ` Peter Xu [this message]
2023-08-16 14:25 ` [PATCH v4 3/8] migration: Fix possible race when shutting down to_dst_file Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 4/8] migration: Remove redundant cleanup of postcopy_qemufile_src Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 5/8] migration: Consolidate return path closing code Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 6/8] migration: Replace the return path retry logic Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 7/8] migration: Move return path cleanup to main migration thread Fabiano Rosas
2023-08-16 14:25 ` [PATCH v4 8/8] migration: Add a wrapper to cleanup migration files Fabiano Rosas
2023-08-16 15:18 ` Peter Xu
[not found] ` <87leealt8h.fsf@suse.de>
[not found] ` <ZN0k/DFQQIeEpgjl@x1n>
2023-08-16 19:37 ` Peter Xu
2023-08-16 21:20 ` Fabiano Rosas
2023-08-16 21:55 ` Peter Xu
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