summaryrefslogtreecommitdiffstats
Commit message (Collapse)AuthorAgeFilesLines
* tty: Remove ASYNC_CLOSING checks in open()/hangup() methodsPeter Hurley2015-10-179-142/+11
| | | | | | | | | | | | | | | | | | | | | | | | | Since at least before 2.6.30, tty drivers that do not drop the tty lock while closing cannot observe ASYNC_CLOSING set while holding the tty lock; this includes the tty driver's open() and hangup() methods, since the tty core calls these methods holding the tty lock. For these drivers, waiting for ASYNC_CLOSING to clear while opening is not required, since this condition cannot occur. Similarly, even when the open() method drops and reacquires the tty lock after blocking, ASYNC_CLOSING cannot be set (again, for drivers that do not drop the tty lock while closing). Now that tty port drivers no longer drop the tty lock while closing (since 'tty: Remove tty_wait_until_sent_from_close()'), the same conditions apply: waiting for ASYNC_CLOSING to clear while opening is not required, nor is re-checking ASYNC_CLOSING after dropping and reacquiring the tty lock while blocking (eg., in *_block_til_ready()). Note: The ASYNC_CLOSING flag state is still maintained since several bitrotting drivers use it for (dubious) other purposes. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove tty_wait_until_sent_from_close()Peter Hurley2015-10-175-30/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_wait_until_sent_from_close() drops the tty lock while waiting for the tty driver to finish sending previously accepted data (ie., data remaining in its write buffer and transmit fifo). tty_wait_until_sent_from_close() was added by commit a57a7bf3fc7e ("TTY: define tty_wait_until_sent_from_close") to prevent the entire tty subsystem from being unable to open new ttys while waiting for one tty to close while output drained. However, since commit 0911261d4cb6 ("tty: Don't take tty_mutex for tty count changes"), holding a tty lock while closing does not prevent other ttys from being opened/closed/hung up, but only prevents lifetime event changes for the tty under lock. Holding the tty lock while waiting for output to drain does prevent parallel non-blocking opens (O_NONBLOCK) from advancing or returning while the tty lock is held. However, all parallel opens _already_ block even if the tty lock is dropped while closing and the parallel open advances. Blocking in open has been in mainline since at least 2.6.29 (see tty_port_block_til_ready(); note the test for O_NONBLOCK is _after_ the wait while ASYNC_CLOSING). IOW, before this patch a non-blocking open will sleep anyway for the _entire_ duration of a parallel hardware shutdown, and when it wakes, the error return will cause a release of its tty, and it will restart with a fresh attempt to open. Similarly with a blocking open that is already waiting; when it's woken, the hardware shutdown has already completed to ASYNC_INITIALIZED is not set, which forces a release and restart as well. So, holding the tty lock across the _entire_ close (which is what this patch does), even while waiting for output to drain, is equivalent to the current outcome wrt parallel opens. Cc: Alan Cox <alan@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> CC: Arnd Bergmann <arnd@arndb.de> CC: Karsten Keil <isdn@linux-pingi.de> CC: linuxppc-dev@lists.ozlabs.org Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: tegra: Add helper function for handling RX bufferJon Hunter2015-10-171-42/+24
| | | | | | | | | | In the tegra UART driver there are three places where the RX DMA buffer is handled and pushed up to the tty layer. In all three instances the same functions are called and so instead of duplicating the code in three places, move this code to a new helper function and use this new function. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: tegra: Remove redundant code and check in tegra_uart_stop_rx()Jon Hunter2015-10-171-10/+7
| | | | | | | | | | | | | The serial-tegra driver always uses DMA and hence the driver always allocates DMA channels. Therefore, the test to see if the RX DMA channel is initialised in tegra_uart_stop_rx() is unnecessary and so remove the test and the code that corresponds to the case where the RX DMA channel is not initialised. Please note that the call to tegra_uart_stop_rx() should always be before the call to tegra_uart_shutdown() which will uninitialise the RX DMA channel. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: tegra: Remove unnecessary return statementsJon Hunter2015-10-171-11/+0
| | | | | | | | Some functions in the serial-tegra driver have unnecessary return statements at the end of a void function and so remove them. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: tegra: Handle another RX race conditionJon Hunter2015-10-171-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 853a699739fe ("serial: tegra: handle race condition on uart rx side") attempted to fix a race condition between the RX end of transmission interrupt and RX DMA completion callback. Despite this fix there is still another case where these two paths can race and result in duplicated data. The race condition is as follows: 1. DMA completion interrupt occurs and schedules tasklet to call DMA callback. 2. DMA callback for the UART driver starts to execute. This will copy the data from the DMA buffer and restart the DMA. This is done under uart port spinlock. 3. During the callback, UART interrupt is raised for end of receive. The UART ISR runs and waits to acquire port spinlock held by the DMA callback. 4. DMA callback gives up spinlock after copying the data, but before restarting DMA. 5. UART ISR acquires the spin lock and reads the same DMA buffer because DMA has not been restarted yet. The release of the spinlock during the DMA callback was introduced by commit 9b88748b362c ("tty: serial: tegra: drop uart_port->lock before calling tty_flip_buffer_push()") to fix a spinlock lock-up issue when calling tty_flip_buffer_push(). However, since then commit a9c3f68f3cd8 ("tty: Fix low_latency BUG") migrated tty_flip_buffer_push() to always use a workqueue, allowing tty_flip_buffer_push() to be called from within atomic sections. Therefore, we can remove the unlocking of the spinlock from the DMA callback and UART ISR and this will ensure that the race condition no longer occurs. Reported-by: Christopher Freeman <cfreeman@nvidia.com> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: 8250_omap: Remove RTS clearPeter Hurley2015-10-171-1/+0
| | | | | | | | Clearing UART_MCR_RTS or UART_MCR_XONANY is unnecessary; these bits are never set in the shadow mcr. The RTS clear is especially confusing. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: Enable Freescale 16550 workaround on armScott Wood2015-10-172-2/+7
| | | | | | | | | | | | | The same serial hardware is present on LS2080A which is arm64, and LS1021A which is arm32, so don't limit the workaround to PPC. Unlike PPC which uses arch/powerpc/kernel/legacy_serial.c, the ARM targets use drivers/tty/serial/of_serial.c, so add the handle_irq override check there as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: men_z135_uart.c: use mcb memory region size instead of ↵Andreas Werner2015-10-171-8/+15
| | | | | | | | | | | | | | | | hardcoded one There is no need to hardcode the MEN_Z135_MEM_SIZE. The MCB subsystem already knowns the size which is located in the chameleon table. MCB parse the chameleon table to get the resources of each IP and provide the mcb_request_mem function to get those resources. Use mcb_request_mem to get the resources. This function also takes care of the memory region naming allocated by the driver for each of the instances. Signed-off-by: Andreas Werner <andy@wernerandy.de> Acked-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: atmel: fix compiler warning on address castAndre Przywara2015-10-171-1/+1
| | | | | | | | | | | | | | | | Turning on KVM and LPAE support on top of a multi_v7_defconfig will produce a compiler warning in the Atmel serial driver: drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port': drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] if ((void *)port->mapbase != ser->iomem_base) ^ Fix that by using the cast on the right hand side instead, as similar code already does in other drivers. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 4.3-rc5 into tty-nextGreg Kroah-Hartman2015-10-12421-2011/+3234
|\ | | | | | | | | | | | | We want the tty fixes and reverts in here as well so that people can properly test and use it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Linux 4.3-rc5v4.3-rc5Linus Torvalds2015-10-111-2/+2
| |
| * Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2015-10-112-7/+8
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "Fix a long standing state race in finish_task_switch()" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix TASK_DEAD race in finish_task_switch()
| | * sched/core: Fix TASK_DEAD race in finish_task_switch()Peter Zijlstra2015-10-062-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So the problem this patch is trying to address is as follows: CPU0 CPU1 context_switch(A, B) ttwu(A) LOCK A->pi_lock A->on_cpu == 0 finish_task_switch(A) prev_state = A->state <-. WMB | A->on_cpu = 0; | UNLOCK rq0->lock | | context_switch(C, A) `-- A->state = TASK_DEAD prev_state == TASK_DEAD put_task_struct(A) context_switch(A, C) finish_task_switch(A) A->state == TASK_DEAD put_task_struct(A) The argument being that the WMB will allow the load of A->state on CPU0 to cross over and observe CPU1's store of A->state, which will then result in a double-drop and use-after-free. Now the comment states (and this was true once upon a long time ago) that we need to observe A->state while holding rq->lock because that will order us against the wakeup; however the wakeup will not in fact acquire (that) rq->lock; it takes A->pi_lock these days. We can obviously fix this by upgrading the WMB to an MB, but that is expensive, so we'd rather avoid that. The alternative this patch takes is: smp_store_release(&A->on_cpu, 0), which avoids the MB on some archs, but not important ones like ARM. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> # v3.1+ Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: manfred@colorfullife.com Cc: will.deacon@arm.com Fixes: e4a52bcb9a18 ("sched: Remove rq->lock from the first half of ttwu()") Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2015-10-113-1/+4
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Thomas Glexiner: "Fix build breakage on powerpc in perf tools" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Fix build break on powerpc due to sample_reg_masks
| | * \ Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar2015-10-073-1/+4
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fix from Arnaldo Carvalho de Melo: - Fix build break on (at least) powerpc due to sample_reg_masks, not being available for linking. (Sukadev Bhattiprolu) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | perf tools: Fix build break on powerpc due to sample_reg_masksSukadev Bhattiprolu2015-10-073-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_regs.c does not get built on Powerpc as CONFIG_PERF_REGS is false. So the weak definition for 'sample_regs_masks' doesn't get picked up. Adding perf_regs.o to util/Build unconditionally, exposes a redefinition error for 'perf_reg_value()' function (due to the static inline version in util/perf_regs.h). So use #ifdef HAVE_PERF_REGS_SUPPORT' around that function. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20150930182836.GA27858@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2015-10-111-2/+2
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull maintainer email update from Thomas Gleixner: "Change Matt Fleming's email address in the maintainers file" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Change Matt Fleming's email address
| | * | | | MAINTAINERS: Change Matt Fleming's email addressMatt Fleming2015-10-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My Intel email address will soon expire. Replace it with my personal address so people still know where to send patches. Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1444494136-10333-1-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2015-10-112-1/+6
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Three trivial commits: - Fix a kerneldoc regression - Export handle_bad_irq to unbreak a driver in next - Add an accessor for the of_node field so refactoring in next does not depend on merge ordering" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqdomain: Add an accessor for the of_node field genirq: Fix handle_bad_irq kerneldoc comment genirq: Export handle_bad_irq
| | * | | | | irqdomain: Add an accessor for the of_node fieldMarc Zyngier2015-10-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we're about to remove the of_node field from the irqdomain structure, introduce an accessor for it. Subsequent patches will take care of the actual repainting. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1444402211-1141-1-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | | | | genirq: Fix handle_bad_irq kerneldoc commentArnd Bergmann2015-10-091-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent cleanup removed the 'irq' parameter from many functions, but left the documentation for this in place for at least one function. This removes it. Fixes: bd0b9ac405e1 ("genirq: Remove irq argument from irq flow handlers") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: kbuild-all@01.org Cc: Austin Schuh <austin@peloton-tech.com> Cc: Santosh Shilimkar <ssantosh@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | | | | genirq: Export handle_bad_irqArnd Bergmann2015-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A cleanup of the omap gpio driver introduced a use of the handle_bad_irq() function in a device driver that can be a loadable module. This broke the ARM allmodconfig build: ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined! This patch exports the handle_bad_irq symbol in order to allow the use in modules. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Santosh Shilimkar <ssantosh@kernel.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Austin Schuh <austin@peloton-tech.com> Cc: Tony Lindgren <tony@atomide.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | Merge tag 'scsi-fixes' of ↵Linus Torvalds2015-10-113-14/+33
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "This is a set of three bug fixes, two of which are regressions from recent updates (the 3ware one from 4.1 and the device handler fixes from 4.2)" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: 3w-9xxx: don't unmap bounce buffered commands scsi_dh: Use the correct module name when loading device handler libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop
| | * | | | | | 3w-9xxx: don't unmap bounce buffered commandsChristoph Hellwig2015-10-071-7/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 3w controller don't dma map small single SGL entry commands but instead bounce buffer them. Add a helper to identify these commands and don't call scsi_dma_unmap for them. Based on an earlier patch from James Bottomley. Fixes: 118c85 ("3w-9xxx: fix command completion race") Reported-by: Tóth Attila <atoth@atoth.sote.hu> Tested-by: Tóth Attila <atoth@atoth.sote.hu> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Adam Radford <aradford@gmail.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
| | * | | | | | scsi_dh: Use the correct module name when loading device handlerPaul Mackerras2015-10-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a bug in recent kernels which results in failure to boot on systems that have multipath SCSI disks. I observed this failure on a POWER8 server where all the disks are multipath SCSI disks. The symptoms are several messages like this on the console: [ 3.018700] device-mapper: table: 253:0: multipath: error attaching hardware handler [ 3.018828] device-mapper: ioctl: error adding target to table and the system does not find its disks, and therefore fails to boot. Bisection revealed that the bug was introduced in commit 566079c849cf, "dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath". The specific reason for the failure is that where we previously loaded the "scsi_dh_alua" module, we are now trying to load the "alua" module, which doesn't exist. To fix this, we change the request_module call in scsi_dh_lookup() to prepend "scsi_dh_" to the name, just like the old code in drivers/md/dm-mpath.c:parse_hw_handler() used to do. [jejb: also fixes issue spotted by Sasha Levin that formatting characters could be passed in via sysfs and cause issues with request_module()] Fixes: 566079c849cf Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Cc: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
| | * | | | | | libiscsi: Fix iscsi_check_transport_timeouts possible infinite loopAriel Nahum2015-09-171-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Connection last_ping is not being updated when iscsi_send_nopout fails. Not updating the last_ping will cause firing a timer to a past time (last_ping + ping_tmo < current_time) which triggers an infinite loop of iscsi_check_transport_timeouts() and hogs the cpu. Fix this issue by checking the return value of iscsi_send_nopout. If it fails set the next_timeout to one second later. Signed-off-by: Ariel Nahum <arieln@mellanox.com> Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <JBottomley@Odin.com>
| * | | | | | | Merge tag 'md/4.3-rc4-fix' of git://neil.brown.name/mdLinus Torvalds2015-10-112-4/+4
| |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md bugfix from Neil Brown: "One bug fix for raid1/raid10. Very careless bug earler in 4.3-rc, now fixed :-)" * tag 'md/4.3-rc4-fix' of git://neil.brown.name/md: crash in md-raid1 and md-raid10 due to incorrect list manipulation
| | * | | | | | | crash in md-raid1 and md-raid10 due to incorrect list manipulationMikulas Patocka2015-10-092-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 55ce74d4bfe1b9444436264c637f39a152d1e5ac (md/raid1: ensure device failure recorded before write request returns) is causing crash in the LVM2 testsuite test shell/lvchange-raid.sh. For me the crash is 100% reproducible. The reason for the crash is that the newly added code in raid1d moves the list from conf->bio_end_io_list to tmp, then tests if tmp is non-empty and then incorrectly pops the bio from conf->bio_end_io_list (which is empty because the list was alrady moved). Raid-10 has a similar bug. Kernel Fault: Code=15 regs=000000006ccb8640 (Addr=0000000100000000) CPU: 3 PID: 1930 Comm: mdX_raid1 Not tainted 4.2.0-rc5-bisect+ #35 task: 000000006cc1f258 ti: 000000006ccb8000 task.ti: 000000006ccb8000 YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI PSW: 00001000000001001111111000001111 Not tainted r00-03 000000ff0804fe0f 000000001059d000 000000001059f818 000000007f16be38 r04-07 000000001059d000 000000007f16be08 0000000000200200 0000000000000001 r08-11 000000006ccb8260 000000007b7934d0 0000000000000001 0000000000000000 r12-15 000000004056f320 0000000000000000 0000000000013dd0 0000000000000000 r16-19 00000000f0d00ae0 0000000000000000 0000000000000000 0000000000000001 r20-23 000000000800000f 0000000042200390 0000000000000000 0000000000000000 r24-27 0000000000000001 000000000800000f 000000007f16be08 000000001059d000 r28-31 0000000100000000 000000006ccb8560 000000006ccb8640 0000000000000000 sr00-03 0000000000249800 0000000000000000 0000000000000000 0000000000249800 sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 IASQ: 0000000000000000 0000000000000000 IAOQ: 000000001059f61c 000000001059f620 IIR: 0f8010c6 ISR: 0000000000000000 IOR: 0000000100000000 CPU: 3 CR30: 000000006ccb8000 CR31: 0000000000000000 ORIG_R28: 000000001059d000 IAOQ[0]: call_bio_endio+0x34/0x1a8 [raid1] IAOQ[1]: call_bio_endio+0x38/0x1a8 [raid1] RP(r2): raid_end_bio_io+0x88/0x168 [raid1] Backtrace: [<000000001059f818>] raid_end_bio_io+0x88/0x168 [raid1] [<00000000105a4f64>] raid1d+0x144/0x1640 [raid1] [<000000004017fd5c>] kthread+0x144/0x160 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 55ce74d4bfe1 ("md/raid1: ensure device failure recorded before write request returns.") Fixes: 95af587e95aa ("md/raid10: ensure device failure recorded before write request returns.") Signed-off-by: NeilBrown <neilb@suse.com>
| * | | | | | | | Merge tag 'usb-4.3-rc5' of ↵Linus Torvalds2015-10-109-4/+43
| |\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB fixes from Greg KH: "Here are some small USB and PHY fixes and quirk updates for 4.3-rc5. Nothing major here, full details in the shortlog, and all of these have been in linux-next for a while" * tag 'usb-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: Add device quirk for Logitech PTZ cameras USB: chaoskey read offset bug USB: Add reset-resume quirk for two Plantronics usb headphones. usb: renesas_usbhs: Add support for R-Car H3 usb: renesas_usbhs: fix build warning if 64-bit architecture usb: gadget: bdc: fix memory leak phy: berlin-sata: Fix module autoload for OF platform driver phy: rockchip-usb: power down phy when rockchip phy probe phy: qcom-ufs: fix build error when the component is built as a module
| | * | | | | | | | usb: Add device quirk for Logitech PTZ camerasVincent Palatin2015-10-041-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a device quirk for the Logitech PTZ Pro Camera and its sibling the ConferenceCam CC3000e Camera. This fixes the failed camera enumeration on some boot, particularly on machines with fast CPU. Tested by connecting a Logitech PTZ Pro Camera to a machine with a Haswell Core i7-4600U CPU @ 2.10GHz, and doing thousands of reboot cycles while recording the kernel logs and taking camera picture after each boot. Before the patch, more than 7% of the boots show some enumeration transfer failures and in a few of them, the kernel is giving up before actually enumerating the webcam. After the patch, the enumeration has been correct on every reboot. Signed-off-by: Vincent Palatin <vpalatin@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | USB: chaoskey read offset bugAlexander Inyukhin2015-10-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rng reads in chaoskey driver could return the same data under the certain conditions. Signed-off-by: Alexander Inyukhin <shurick@sectorb.msk.ru> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | USB: Add reset-resume quirk for two Plantronics usb headphones.Yao-Wen Mao2015-10-041-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two headphones need a reset-resume quirk to properly resume to original volume level. Signed-off-by: Yao-Wen Mao <yaowen@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | Merge tag 'phy-for-4.3-rc' of ↵Greg Kroah-Hartman2015-10-033-0/+18
| | |\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux-phy into usb-linus Kishon writes: phy: for 4.3-rc *) Fix compiler error in qcom-ufs when it is built as module *) Power down rockchip-usb PHY during probe to save power consumption *) Fix module autoload for berlin-sata PHY driver Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
| | | * | | | | | | | phy: berlin-sata: Fix module autoload for OF platform driverLuis de Bethencourt2015-09-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
| | | * | | | | | | | phy: rockchip-usb: power down phy when rockchip phy probehuang lin2015-09-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rockchip phy are enable when soc reset, to save power consumption, we disable it when probe, and enable each phy when it use Signed-off-by: huang lin <hl@rock-chips.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
| | | * | | | | | | | phy: qcom-ufs: fix build error when the component is built as a moduleYaniv Gardi2015-09-251-0/+11
| | | | |/ / / / / / | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export the following functions in order to avoid build errors when the component PHY_QCOM_UFS is compiled as a module: ERROR: "ufs_qcom_phy_disable_ref_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_enable_ref_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_is_pcs_ready" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_disable_iface_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_start_serdes" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_calibrate_phy" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_enable_dev_ref_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_set_tx_lane_enable" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_disable_dev_ref_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_save_controller_version" [drivers/scsi/ufs/ufs-qcom.ko] undefined! ERROR: "ufs_qcom_phy_enable_iface_clk" [drivers/scsi/ufs/ufs-qcom.ko] undefined! make[1]: *** [__modpost] Error 1 Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
| | * | | | | | | | Merge tag 'fixes-for-v4.3-rc4' of ↵Greg Kroah-Hartman2015-10-034-3/+11
| | |\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-linus Felipe writes: usb: fixes for v4.3-rc4 A memory leak fix for the BCD UDC driver, a build warning fix on Renesas and a new device ID for R-Car H3. Nothing major. Signed-off-by: Felipe Balbi <balbi@ti.com>
| | | * | | | | | | | usb: renesas_usbhs: Add support for R-Car H3Yoshihiro Shimoda2015-09-302-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a compatible string to support for R-Car H3. Since the HS-USB controller of R-Car H3 is almost the same specification with R-Car Gen2 (these have 16 pipes and usb-dmac), this patch sets the "type" of renesas_usbhs_driver_param to USBHS_TYPE_RCAR_GEN2. Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
| | | * | | | | | | | usb: renesas_usbhs: fix build warning if 64-bit architectureYoshihiro Shimoda2015-09-302-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following warning if 64-bit architecture environment: ./drivers/usb/renesas_usbhs/common.c:496:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] dparam->type = of_id ? (u32)of_id->data : 0; Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
| | | * | | | | | | | usb: gadget: bdc: fix memory leakSudip Mukherjee2015-09-301-1/+3
| | |/ / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If dma_pool_alloc() fails we are jumping to fail and releasing all the bd_tables which have been added to the chain but we missed freeing this bd_table which was just allocated and still not added to the chain of bd_table. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Felipe Balbi <balbi@ti.com>
| * | | | | | | | | Merge tag 'tty-4.3-rc5' of ↵Linus Torvalds2015-10-106-28/+79
| |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver fixes from Greg KH: "Here are a few bug fixes for the tty core that resolve reported issues, and some serial driver fixes as well (including the much-reported imx driver problem) All of these have been in linux-next with no reported problems" * tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: drivers/tty: require read access for controlling terminal serial: 8250: add uart_config entry for PORT_RT2880 tty: fix data race on tty_buffer.commit tty: fix data race in tty_buffer_flush tty: fix data race in flush_to_ldisc tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c serial: atmel: fix error path of probe function tty: don't leak cdev in tty_cdev_add() Revert "serial: imx: remove unbalanced clk_prepare"
| | * | | | | | | | | drivers/tty: require read access for controlling terminalJann Horn2015-10-041-4/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is mostly a hardening fix, given that write-only access to other users' ttys is usually only given through setgid tty executables. Signed-off-by: Jann Horn <jann@thejh.net> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | serial: 8250: add uart_config entry for PORT_RT2880Mans Rullgard2015-10-041-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds an entry to the uart_config table for PORT_RT2880 enabling rx/tx FIFOs. The UART is actually a Palmchip BK-3103 which is found in several devices from Alchemy/RMI, Ralink, and Sigma Designs. Signed-off-by: Mans Rullgard <mans@mansr.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | tty: fix data race on tty_buffer.commitDmitry Vyukov2015-10-041-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Race on buffer data happens when newly committed data is picked up by an old flush work in the following scenario: __tty_buffer_request_room does a plain write of tail->commit, no barriers were executed before that. At this point flush_to_ldisc reads this new value of commit, and reads buffer data, no barriers in between. The committed buffer data is not necessary visible to flush_to_ldisc. Similar bug happens when tty_schedule_flip commits data. Update commit with smp_store_release and read commit with smp_load_acquire, as it is commit that signals data readiness. This is orthogonal to the existing synchronization on tty_buffer.next, which is required to not dismiss a buffer with unconsumed data. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | tty: fix data race in tty_buffer_flushDmitry Vyukov2015-10-041-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_buffer_flush frees not acquired buffers. As the result, for example, read of b->size in tty_buffer_free can return garbage value which will lead to a huge buffer hanging in the freelist. This is just the benignest manifestation of freeing of a not acquired object. If the object is passed to kfree, heap can be corrupted. Acquire visibility over the buffer before freeing it. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | tty: fix data race in flush_to_ldiscDmitry Vyukov2015-10-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | flush_to_ldisc reads port->itty and checks that it is not NULL, concurrently release_tty sets port->itty to NULL. It is possible that flush_to_ldisc loads port->itty once, ensures that it is not NULL, but then reloads it again and uses. The second load can already return NULL, which will cause a crash. Use READ_ONCE to read port->itty. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.cKosuke Tatsukawa2015-10-041-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My colleague ran into a program stall on a x86_64 server, where n_tty_read() was waiting for data even if there was data in the buffer in the pty. kernel stack for the stuck process looks like below. #0 [ffff88303d107b58] __schedule at ffffffff815c4b20 #1 [ffff88303d107bd0] schedule at ffffffff815c513e #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23 #5 [ffff88303d107dd0] tty_read at ffffffff81368013 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57 #8 [ffff88303d107f00] sys_read at ffffffff811a4306 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7 There seems to be two problems causing this issue. First, in drivers/tty/n_tty.c, __receive_buf() stores the data and updates ldata->commit_head using smp_store_release() and then checks the wait queue using waitqueue_active(). However, since there is no memory barrier, __receive_buf() could return without calling wake_up_interactive_poll(), and at the same time, n_tty_read() could start to wait in wait_woken() as in the following chart. __receive_buf() n_tty_read() ------------------------------------------------------------------------ if (waitqueue_active(&tty->read_wait)) /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ add_wait_queue(&tty->read_wait, &wait); ... if (!input_available_p(tty, 0)) { smp_store_release(&ldata->commit_head, ldata->read_head); ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ The second problem is that n_tty_read() also lacks a memory barrier call and could also cause __receive_buf() to return without calling wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken() as in the chart below. __receive_buf() n_tty_read() ------------------------------------------------------------------------ spin_lock_irqsave(&q->lock, flags); /* from add_wait_queue() */ ... if (!input_available_p(tty, 0)) { /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ smp_store_release(&ldata->commit_head, ldata->read_head); if (waitqueue_active(&tty->read_wait)) __add_wait_queue(q, wait); spin_unlock_irqrestore(&q->lock,flags); /* from add_wait_queue() */ ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ There are also other places in drivers/tty/n_tty.c which have similar calls to waitqueue_active(), so instead of adding many memory barrier calls, this patch simply removes the call to waitqueue_active(), leaving just wake_up*() behind. This fixes both problems because, even though the memory access before or after the spinlocks in both wake_up*() and add_wait_queue() can sneak into the critical section, it cannot go past it and the critical section assures that they will be serialized (please see "INTER-CPU ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a better explanation). Moreover, the resulting code is much simpler. Latency measurement using a ping-pong test over a pty doesn't show any visible performance drop. Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | serial: atmel: fix error path of probe functionUwe Kleine-König2015-10-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If atmel_init_gpios fails the port has already been marked as busy (in line 2629), so this must be undone in the error path. This bug was introduced because I created the patch that finally became 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") on top of 3.19 which didn't have commit 6fbb9bdf0f3f ("tty/serial: at91: fix error handling in atmel_serial_probe()") yet. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Fixes: 722ccf416ac2 ("serial: atmel: fix error handling when mctrl_gpio_init fails") Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * | | | | | | | | tty: don't leak cdev in tty_cdev_add()Leon Yu2015-10-041-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly dynamic") which mixes using cdev_alloc() and cdev_init() is problematic. Subsequent call to cdev_init() after cdev_alloc() sets kobj release method from cdev_dynamic_release() to cdev_default_release() and thus makes it impossible to free allocated cdev. This patch also consolidates error path of cdev_add() as cdev can also leak here if things went wrong. Signed-off-by: Leon Yu <chianglungyu@gmail.com> Fixes: a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly dynamic") Acked-by: Richard Watts <rrw@kynesim.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
OpenPOWER on IntegriCloud