|| ||Al Viro <viro-AT-ZenIV.linux.org.uk> |
|| ||Mimi Zohar <zohar-AT-linux.vnet.ibm.com> |
|| ||Re: [PATCH v3 10/12] ima: defer calling __fput() |
|| ||Thu, 22 Mar 2012 14:22:12 +0000|
David Safford <safford-AT-linux.vnet.ibm.com>,
Dmitry Kasatkin <dmitry.kasatkin-AT-intel.com>,
Matt Helsley <matt.helsley-AT-gmail.com>,
Mimi Zohar <zohar-AT-us.ibm.com>|
|| ||Article, Thread
On Wed, Mar 21, 2012 at 02:54:15PM -0400, Mimi Zohar wrote:
> If a file is closed before it is munmapped, __fput() is called with
> the mmap_sem taken. With IMA-appraisal enabled, this results in an
> mmap_sem/i_mutex lockdep. ima_defer_fput() increments the f_count
> to defer __fput() being called until after the mmap_sem is released.
NAK. It's far too heavy-weight for what's a very common path. Worse,
it causes different locking conditions on IMA and non-IMA kernels and makes
bugs harder to spot. Rejected with extreme prejudice; please, fix your
BTW, you've missed several other places in mm/* doing fput(), so it wouldn't
be enough to paper over your problem anyway.
Final fput() *can* happen under mmap_sem. Period.
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html
to post comments)