kernel/linux.git/drivers/spi, branch v4.4.235

spi: spidev: fix a potential use-after-free in spidev_release()

2020-07-22T07:10:01+00:00

[ Upstream commit 06096cc6c5a84ced929634b0d79376b94c65a4bd ] If an spi device is unbounded from the driver before the release process, there will be an NULL pointer reference when it's referenced in spi_slave_abort(). Fix it by checking it's already freed before reference. Signed-off-by: Zhenzhong Duan Link: https://lore.kernel.org/r/20200618032125.4650-2-zhenzhong.duan@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: spidev: fix a race between spidev_release and spidev_remove

2020-07-22T07:10:01+00:00

[ Upstream commit abd42781c3d2155868821f1b947ae45bbc33330d ] Imagine below scene, spidev is referenced after it's freed. spidev_release() spidev_remove() ... spin_lock_irq(&spidev->spi_lock); spidev->spi = NULL; spin_unlock_irq(&spidev->spi_lock); mutex_lock(&device_list_lock); dofree = (spidev->spi == NULL); if (dofree) kfree(spidev); mutex_unlock(&device_list_lock); mutex_lock(&device_list_lock); list_del(&spidev->device_entry); device_destroy(spidev_class, spidev->devt); clear_bit(MINOR(spidev->devt), minors); if (spidev->users == 0) kfree(spidev); mutex_unlock(&device_list_lock); Fix it by resetting spidev->spi in device_list_lock's protection. Signed-off-by: Zhenzhong Duan Link: https://lore.kernel.org/r/20200618032125.4650-1-zhenzhong.duan@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: dw: Return any value retrieved from the dma_transfer callback

2020-06-20T08:23:22+00:00

[ Upstream commit f0410bbf7d0fb80149e3b17d11d31f5b5197873e ] DW APB SSI DMA-part of the driver may need to perform the requested SPI-transfer synchronously. In that case the dma_transfer() callback will return 0 as a marker of the SPI transfer being finished so the SPI core doesn't need to wait and may proceed with the SPI message trasnfers pumping procedure. This will be needed to fix the problem when DMA transactions are finished, but there is still data left in the SPI Tx/Rx FIFOs being sent/received. But for now make dma_transfer to return 1 as the normal dw_spi_transfer_one() method. Signed-off-by: Serge Semin Cc: Georgy Vlasov Cc: Ramil Zaripov Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Andy Shevchenko Cc: Feng Tang Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200529131205.31838-3-Sergey.Semin@baikalelectronics.ru Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: dw: Enable interrupts in accordance with DMA xfer mode

2020-06-20T08:23:19+00:00

[ Upstream commit 43dba9f3f98c2b184a19f856f06fe22817bfd9e0 ] It's pointless to track the Tx overrun interrupts if Rx-only SPI transfer is issued. Similarly there is no need in handling the Rx overrun/underrun interrupts if Tx-only SPI transfer is executed. So lets unmask the interrupts only if corresponding SPI transactions are implied. Co-developed-by: Georgy Vlasov Signed-off-by: Georgy Vlasov Signed-off-by: Serge Semin Cc: Ramil Zaripov Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Paul Burton Cc: Ralf Baechle Cc: Arnd Bergmann Cc: Andy Shevchenko Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200522000806.7381-3-Sergey.Semin@baikalelectronics.ru Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: dw: Zero DMA Tx and Rx configurations on stack

2020-06-20T08:23:19+00:00

[ Upstream commit 3cb97e223d277f84171cc4ccecab31e08b2ee7b5 ] Some DMA controller drivers do not tolerate non-zero values in the DMA configuration structures. Zero them to avoid issues with such DMA controller drivers. Even despite above this is a good practice per se. Fixes: 7063c0d942a1 ("spi/dw_spi: add DMA support") Signed-off-by: Andy Shevchenko Acked-by: Feng Tang Cc: Feng Tang Link: https://lore.kernel.org/r/20200506153025.21441-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: bcm2835: Fix controller unregister order

2020-06-20T08:23:17+00:00

[ Upstream commit 9dd277ff92d06f6aa95b39936ad83981d781f49b ] The BCM2835 SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835_spi_remove() tears down the DMA channels and turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_controller(). Note that the struct spi_controller as well as the driver-private data are not freed until after bcm2835_spi_remove() has finished, so accessing them is safe. Fixes: 247263dba208 ("spi: bcm2835: use devm_spi_register_master()") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.13+ Link: https://lore.kernel.org/r/2397dd70cdbe95e0bc4da2b9fca0f31cb94e5aed.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: pxa2xx: Fix controller unregister order

2020-06-20T08:23:17+00:00

[ Upstream commit 32e5b57232c0411e7dea96625c415510430ac079 ] The PXA2xx SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes pxa2xx_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: pxa2xx_spi_remove() disables the chip, rendering the SPI bus inaccessible even though the SPI controller is still registered. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. Because their drivers cannot access the SPI bus, e.g. to quiesce interrupts, the slave devices may be left in an improper state. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unregistering the controller and specifically after unbinding of slaves. Fix by reverting to the non-devm variant of spi_register_controller(). An alternative approach would be to use device-managed functions for all steps in pxa2xx_spi_remove(), e.g. by calling devm_add_action_or_reset() on probe. However that approach would add more LoC to the driver and it wouldn't lend itself as well to backporting to stable. The improper use of devm_spi_register_controller() was introduced in 2013 by commit a807fcd090d6 ("spi: pxa2xx: use devm_spi_register_master()"), but all earlier versions of the driver going back to 2006 were likewise broken because they invoked spi_unregister_master() at the end of pxa2xx_spi_remove(), rather than at the beginning. Fixes: e0c9905e87ac ("[PATCH] SPI: add PXA2xx SSP SPI Driver") Signed-off-by: Lukas Wunner Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org # v2.6.17+ Cc: Tsuchiya Yuto Link: https://bugzilla.kernel.org/show_bug.cgi?id=206403#c1 Link: https://lore.kernel.org/r/834c446b1cf3284d2660f1bee1ebe3e737cd02a9.1590408496.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: Fix controller unregister order

2020-06-20T08:23:17+00:00

[ Upstream commit 84855678add8aba927faf76bc2f130a40f94b6f7 ] When an SPI controller unregisters, it unbinds all its slave devices. For this, their drivers may need to access the SPI bus, e.g. to quiesce interrupts. However since commit ffbbdd21329f ("spi: create a message queueing infrastructure"), spi_destroy_queue() is executed before unbinding the slaves. It sets ctlr->running = false, thereby preventing SPI bus access and causing unbinding of slave devices to fail. Fix by unbinding slaves before calling spi_destroy_queue(). Fixes: ffbbdd21329f ("spi: create a message queueing infrastructure") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.4+ Cc: Linus Walleij Link: https://lore.kernel.org/r/8aaf9d44c153fe233b17bc2dec4eb679898d7e7b.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: No need to assign dummy value in spi_unregister_controller()

2020-06-20T08:23:17+00:00

[ Upstream commit ebc37af5e0a134355ea2b62ed4141458bdbd5389 ] The device_for_each_child() doesn't require the returned value to be checked. Thus, drop the dummy variable completely and have no warning anymore: drivers/spi/spi.c: In function ‘spi_unregister_controller’: drivers/spi/spi.c:2480:6: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable] int dummy; ^~~~~ Signed-off-by: Andy Shevchenko Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

spi: dw: Fix controller unregister order

2020-06-20T08:23:17+00:00

[ Upstream commit ca8b19d61e3fce5d2d7790cde27a0b57bcb3f341 ] The Designware SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes dw_spi_remove_host() before unregistering the SPI controller via devres_release_all(). This order is incorrect: dw_spi_remove_host() shuts down the chip, rendering the SPI bus inaccessible even though the SPI controller is still registered. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. Because their drivers cannot access the SPI bus, e.g. to quiesce interrupts, the slave devices may be left in an improper state. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unregistering the controller and specifically after unbinding of slaves. Fix by reverting to the non-devm variant of spi_register_controller(). An alternative approach would be to use device-managed functions for all steps in dw_spi_remove_host(), e.g. by calling devm_add_action_or_reset() on probe. However that approach would add more LoC to the driver and it wouldn't lend itself as well to backporting to stable. Fixes: 04f421e7b0b1 ("spi: dw: use managed resources") Signed-off-by: Lukas Wunner Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org # v3.14+ Cc: Baruch Siach Link: https://lore.kernel.org/r/3fff8cb8ae44a9893840d0688be15bb88c090a14.1590408496.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin