f2b639b2aa
[ Upstream commit 3906f640224dbe7714b52b66d7d68c0812808e19 ]
The crypto notify call occurs with a read mutex held so you must
not do any substantial work directly. In particular, you cannot
call crypto_alloc_* as they may trigger further notifications
which may dead-lock in the presence of another writer.
This patch fixes this by postponing the work into a work queue and
taking the same lock in the module init function.
While we're at it this patch also ensures that all RCU accesses are
marked appropriately (tested with sparse).
Finally this also reveals a race condition in module param show
function as it may be called prior to the module init function.
It's fixed by testing whether crct10dif_tfm is NULL (this is true
iff the init function has not completed assuming fallback is false).
Fixes: 11dcb1037f40 ("crc-t10dif: Allow current transform to be...")
Fixes: b76377543b73 ("crc-t10dif: Pick better transform if one...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.