Messages in this thread | | | Date | Thu, 27 Jul 2023 15:45:26 -0700 | From | Luis Chamberlain <> | Subject | Re: [PATCH RESEND v4 1/1] test_firmware: fix some memory leaks and racing conditions |
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On Fri, Jul 28, 2023 at 12:14:22AM +0200, Mirsad Todorovac wrote: > On 7/27/23 17:36, Luis Chamberlain wrote: > > On Thu, Jul 27, 2023 at 08:16:17AM +0200, Mirsad Todorovac wrote: > > > On 25.4.2023. 20:27, Luis Chamberlain wrote: > > > > On Fri, Apr 21, 2023 at 08:52:06PM +0200, Mirsad Goran Todorovac wrote: > > > > > Some functions were called both from locked and unlocked context, so > > > > > the lock was dropped prematurely, introducing a race condition when > > > > > deadlock was avoided. > > > > > > > > > > Having two locks wouldn't assure a race-proof mutual exclusion. > > > > > > > > > > __test_dev_config_update_bool(), __test_dev_config_update_u8() and > > > > > __test_dev_config_update_size_t() unlocked versions of the functions > > > > > were introduced to be called from the locked contexts as a workaround > > > > > without releasing the main driver's lock and causing a race condition. > > > > > > > > > > This should guarantee mutual exclusion and prevent any race conditions. > > > > > > > > > > Locked versions simply allow for mutual exclusion and call the unlocked > > > > > counterparts, to avoid duplication of code. > > > > > > > > > > trigger_batched_requests_store() and trigger_batched_requests_async_store() > > > > > now return -EBUSY if called with test_fw_config->reqs already allocated, > > > > > so the memory leak is prevented. > > > > > > > > > > The same functions now keep track of the allocated buf for firmware in > > > > > req->fw_buf as release_firmware() will not deallocate this storage for us. > > > > > > > > > > Additionally, in __test_release_all_firmware(), req->fw_buf is released > > > > > before calling release_firmware(req->fw), > > > > > foreach test_fw_config->reqs[i], i = 0 .. test_fw_config->num_requests-1 > > > > > > > > > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > > > Cc: Luis Chamberlain <mcgrof@kernel.org> > > > > > Cc: Russ Weight <russell.h.weight@intel.com> > > > > > Cc: Tianfei zhang <tianfei.zhang@intel.com> > > > > > Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > > > > > Cc: Zhengchao Shao <shaozhengchao@huawei.com> > > > > > Cc: Colin Ian King <colin.i.king@gmail.com> > > > > > Cc: linux-kernel@vger.kernel.org > > > > > Cc: Takashi Iwai <tiwai@suse.de> > > > > > Cc: Kees Cook <keescook@chromium.org> > > > > > Cc: Scott Branden <sbranden@broadcom.com> > > > > > Cc: Luis R. Rodriguez <mcgrof@kernel.org> > > > > > Suggested-by: Dan Carpenter <error27@gmail.com> > > > > > Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> > > > > > > > > Mirad, thanks for this work, good stuff! So the patch just needs to be > > > > adjust with: > > > > > > > > Fixes: 7feebfa487b92 ("test_firmware: add support for request_firmware_into_buf" > > > > Cc: stable@vger.kernel.org # v5.4 > > > > > > > > Then, can you split the patch in two, one which fixes the memory leaks > > > > and another that deals with the mutexes. The second patch might be a fix > > > > for the original code but I can't tell until I see the changes split out. > > > > > > > > The commit log should account for the memory leak and be clear how it > > > > happens. The other commit log for the second patch should clarify what > > > > it fixes and why as well. > > > > > > It seems to me that there is something wrong with the patchwork, as this commit > > > had not yet appeared in 5.4 LTS stable tree? > > > > Did you resend a new v5 with the requested changes? > > Actually, I am not sure what is the procedure, for it is accepted and visible in 5.10+ trees?
Ah its upstream but not on v5.4. Just send a patch to stable folks and include its commit IDs as stable patches typically do.
Luis
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