From: "홍신 shin hong" <hongshin@gmail.com>
To: linux-fsdevel@vger.kernel.org
Subject: BUG? a suspected race bug at alloc_fd()
Date: Fri, 7 Aug 2009 13:55:10 +0900 [thread overview]
Message-ID: <2014bcab0908062155n6973cb7cg43bc5dcb19261a72@mail.gmail.com> (raw)
Hi. I am reporting a suspected race bug at alloc_fd() in Linux 2.6.30.4.
In alloc_fd(), spin_lock(&files->file_lock) synchronizes
the execution of its gurading code block(line 448~486 at fs/file.c).
However, by invocation of expand_files() at line 458,
spin_lock(&file->file_lock) can be released and re-taken
since expand_files() invokes expand_fdtable() and expand_fdtable()
release &files->file_lock and re-take the lock (line 206~208).
For this reason, the execution of alloc_fd() might result race condition
if other threads are scheduled between the lock releasing and re-taking.
Please examine the code and let me know your opinion.
Thank you.
Sincerely
Shin Hong
next reply other threads:[~2009-08-07 4:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-07 4:55 홍신 shin hong [this message]
2009-08-07 11:08 ` BUG? a suspected race bug at alloc_fd() Matthew Wilcox
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