Messages in this thread | | | Date | Thu, 27 Jul 2023 08:16:17 +0200 | Subject | Re: [PATCH RESEND v4 1/1] test_firmware: fix some memory leaks and racing conditions | From | Mirsad Todorovac <> |
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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?
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/log/?qt=grep&q=Mirsad&h=linux-5.4.y
I was accidentally looking whether it passed, and it seems like more than a month since the other commits propagated :-/
Thanks, Mirsad
-- Mirsad Todorovac System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb Republic of Croatia, the European Union
Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu
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