user/sven/linux.git, branch v3.14.29

Linux 3.14.29

2015-01-16T15:00:22Z

mm: Don't count the stack guard page towards RLIMIT_STACK

2015-01-16T14:59:35Z

commit 690eac53daff34169a4d74fc7bfbd388c4896abb upstream. Commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page") made sure that we return the error properly for stack growth conditions. It also theorized that counting the guard page towards the stack limit might break something, but also said "Let's see if anybody notices". Somebody did notice. Apparently android-x86 sets the stack limit very close to the limit indeed, and including the guard page in the rlimit check causes the android 'zygote' process problems. So this adds the (fairly trivial) code to make the stack rlimit check be against the actual real stack size, rather than the size of the vma that includes the guard page. Reported-and-tested-by: Chih-Wei Huang Cc: Jay Foad Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: propagate error from stack expansion even for guard page

2015-01-16T14:59:35Z

commit fee7e49d45149fba60156f5b59014f764d3e3728 upstream. Jay Foad reports that the address sanitizer test (asan) sometimes gets confused by a stack pointer that ends up being outside the stack vma that is reported by /proc/maps. This happens due to an interaction between RLIMIT_STACK and the guard page: when we do the guard page check, we ignore the potential error from the stack expansion, which effectively results in a missing guard page, since the expected stack expansion won't have been done. And since /proc/maps explicitly ignores the guard page (commit d7824370e263: "mm: fix up some user-visible effects of the stack guard page"), the stack pointer ends up being outside the reported stack area. This is the minimal patch: it just propagates the error. It also effectively makes the guard page part of the stack limit, which in turn measn that the actual real stack is one page less than the stack limit. Let's see if anybody notices. We could teach acct_stack_growth() to allow an extra page for a grow-up/grow-down stack in the rlimit test, but I don't want to add more complexity if it isn't needed. Reported-and-tested-by: Jay Foad Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process being killed

2015-01-16T14:59:35Z

commit 9e5e3661727eaf960d3480213f8e87c8d67b6956 upstream. Charles Shirron and Paul Cassella from Cray Inc have reported kswapd stuck in a busy loop with nothing left to balance, but kswapd_try_to_sleep() failing to sleep. Their analysis found the cause to be a combination of several factors: 1. A process is waiting in throttle_direct_reclaim() on pgdat->pfmemalloc_wait 2. The process has been killed (by OOM in this case), but has not yet been scheduled to remove itself from the waitqueue and die. 3. kswapd checks for throttled processes in prepare_kswapd_sleep(): if (waitqueue_active(&pgdat->pfmemalloc_wait)) { wake_up(&pgdat->pfmemalloc_wait); return false; // kswapd will not go to sleep } However, for a process that was already killed, wake_up() does not remove the process from the waitqueue, since try_to_wake_up() checks its state first and returns false when the process is no longer waiting. 4. kswapd is running on the same CPU as the only CPU that the process is allowed to run on (through cpus_allowed, or possibly single-cpu system). 5. CONFIG_PREEMPT_NONE=y kernel is used. If there's nothing to balance, kswapd encounters no voluntary preemption points and repeatedly fails prepare_kswapd_sleep(), blocking the process from running and removing itself from the waitqueue, which would let kswapd sleep. So, the source of the problem is that we prevent kswapd from going to sleep until there are processes waiting on the pfmemalloc_wait queue, and a process waiting on a queue is guaranteed to be removed from the queue only when it gets scheduled. This was done to make sure that no process is left sleeping on pfmemalloc_wait when kswapd itself goes to sleep. However, it isn't necessary to postpone kswapd sleep until the pfmemalloc_wait queue actually empties. To prevent processes from being left sleeping, it's actually enough to guarantee that all processes waiting on pfmemalloc_wait queue have been woken up by the time we put kswapd to sleep. This patch therefore fixes this issue by substituting 'wake_up' with 'wake_up_all' and removing 'return false' in the code snippet from prepare_kswapd_sleep() above. Note that if any process puts itself in the queue after this waitqueue_active() check, or after the wake up itself, it means that the process will also wake up kswapd - and since we are under prepare_to_wait(), the wake up won't be missed. Also we update the comment prepare_kswapd_sleep() to hopefully more clearly describe the races it is preventing. Fixes: 5515061d22f0 ("mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage") Signed-off-by: Vlastimil Babka Signed-off-by: Vladimir Davydov Cc: Mel Gorman Cc: Johannes Weiner Acked-by: Michal Hocko Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mmc: sdhci: Fix sleep in atomic after inserting SD card

2015-01-16T14:59:34Z

commit 2836766a9d0bd02c66073f8dd44796e6cc23848d upstream. Sleep in atomic context happened on Trats2 board after inserting or removing SD card because mmc_gpio_get_cd() was called under spin lock. Fix this by moving card detection earlier, before acquiring spin lock. The mmc_gpio_get_cd() call does not have to be protected by spin lock because it does not access any sdhci internal data. The sdhci_do_get_cd() call access host flags (SDHCI_DEVICE_DEAD). After moving it out side of spin lock it could theoretically race with driver removal but still there is no actual protection against manual card eject. Dmesg after inserting SD card: [ 41.663414] BUG: sleeping function called from invalid context at drivers/gpio/gpiolib.c:1511 [ 41.670469] in_atomic(): 1, irqs_disabled(): 128, pid: 30, name: kworker/u8:1 [ 41.677580] INFO: lockdep is turned off. [ 41.681486] irq event stamp: 61972 [ 41.684872] hardirqs last enabled at (61971): [] _raw_spin_unlock_irq+0x24/0x5c [ 41.693118] hardirqs last disabled at (61972): [] _raw_spin_lock_irq+0x18/0x54 [ 41.701190] softirqs last enabled at (61648): [] __do_softirq+0x234/0x2c8 [ 41.708914] softirqs last disabled at (61631): [] irq_exit+0xd0/0x114 [ 41.716206] Preemption disabled at:[< (null)>] (null) [ 41.721500] [ 41.722985] CPU: 3 PID: 30 Comm: kworker/u8:1 Tainted: G W 3.18.0-rc5-next-20141121 #883 [ 41.732111] Workqueue: kmmcd mmc_rescan [ 41.735945] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 41.743661] [] (show_stack) from [] (dump_stack+0x70/0xbc) [ 41.750867] [] (dump_stack) from [] (gpiod_get_raw_value_cansleep+0x18/0x30) [ 41.759628] [] (gpiod_get_raw_value_cansleep) from [] (mmc_gpio_get_cd+0x38/0x58) [ 41.768821] [] (mmc_gpio_get_cd) from [] (sdhci_request+0x50/0x1a4) [ 41.776808] [] (sdhci_request) from [] (mmc_start_request+0x138/0x268) [ 41.785051] [] (mmc_start_request) from [] (mmc_wait_for_req+0x58/0x1a0) [ 41.793469] [] (mmc_wait_for_req) from [] (mmc_wait_for_cmd+0x58/0x78) [ 41.801714] [] (mmc_wait_for_cmd) from [] (mmc_io_rw_direct_host+0x98/0x124) [ 41.810480] [] (mmc_io_rw_direct_host) from [] (sdio_reset+0x2c/0x64) [ 41.818641] [] (sdio_reset) from [] (mmc_rescan+0x254/0x2e4) [ 41.826028] [] (mmc_rescan) from [] (process_one_work+0x180/0x3f4) [ 41.833920] [] (process_one_work) from [] (worker_thread+0x34/0x4b0) [ 41.841991] [] (worker_thread) from [] (kthread+0xe4/0x104) [ 41.849285] [] (kthread) from [] (ret_from_fork+0x14/0x2c) [ 42.038276] mmc0: new high speed SDHC card at address 1234 Signed-off-by: Krzysztof Kozlowski Fixes: 94144a465dd0 ("mmc: sdhci: add get_cd() implementation") Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

spi: fsl: Fix problem with multi message transfers

2015-01-16T14:59:34Z

commit 4302a59629f7a0bd70fd1605d2b558597517372a upstream. When used via spidev with more than one messages to tranfer via SPI_IOC_MESSAGE the current implementation would return with -EINVAL, since bits_per_word and speed_hz are set in all transfer structs. And in the 2nd loop status will stay at -EINVAL as its not overwritten again via fsl_spi_setup_transfer(). This patch changes this behavious by first checking if one of the messages uses different settings. If this is the case the function will return with -EINVAL. If not, the messages are transferred correctly. Signed-off-by: Stefan Roese Signed-off-by: Mark Brown Cc: Esben Haabendal Signed-off-by: Greg Kroah-Hartman

perf session: Do not fail on processing out of order event

2015-01-16T14:59:34Z

commit f61ff6c06dc8f32c7036013ad802c899ec590607 upstream. Linus reported perf report command being interrupted due to processing of 'out of order' event, with following error: Timestamp below last timeslice flush 0x5733a8 [0x28]: failed to process type: 3 I could reproduce the issue and in my case it was caused by one CPU (mmap) being behind during record and userspace mmap reader seeing the data after other CPUs data were already stored. This is expected under some circumstances because we need to limit the number of events that we queue for reordering when we receive a PERF_RECORD_FINISHED_ROUND or when we force flush due to memory pressure. Reported-by: Linus Torvalds Signed-off-by: Jiri Olsa Acked-by: Ingo Molnar Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Linus Torvalds Cc: Matt Fleming Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1417016371-30249-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo [zhangzhiqiang: backport to 3.10: - adjust context - commit f61ff6c06d struct events_stats was defined in tools/perf/util/event.h while 3.10 stable defined in tools/perf/util/hist.h. - 3.10 stable there is no pr_oe_time() which used for debug. - After the above adjustments, becomes same to the original patch: https://github.com/torvalds/linux/commit/f61ff6c06dc8f32c7036013ad802c899ec590607 ] Signed-off-by: Zhiqiang Zhang Signed-off-by: Greg Kroah-Hartman

perf: Fix events installation during moving group

2015-01-16T14:59:34Z

commit 9fc81d87420d0d3fd62d5e5529972c0ad9eab9cc upstream. We allow PMU driver to change the cpu on which the event should be installed to. This happened in patch: e2d37cd213dc ("perf: Allow the PMU driver to choose the CPU on which to install events") This patch also forces all the group members to follow the currently opened events cpu if the group happened to be moved. This and the change of event->cpu in perf_install_in_context() function introduced in: 0cda4c023132 ("perf: Introduce perf_pmu_migrate_context()") forces group members to change their event->cpu, if the currently-opened-event's PMU changed the cpu and there is a group move. Above behaviour causes problem for breakpoint events, which uses event->cpu to touch cpu specific data for breakpoints accounting. By changing event->cpu, some breakpoints slots were wrongly accounted for given cpu. Vinces's perf fuzzer hit this issue and caused following WARN on my setup: WARNING: CPU: 0 PID: 20214 at arch/x86/kernel/hw_breakpoint.c:119 arch_install_hw_breakpoint+0x142/0x150() Can't find any breakpoint slot [...] This patch changes the group moving code to keep the event's original cpu. Reported-by: Vince Weaver Signed-off-by: Jiri Olsa Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Cc: Yan, Zheng Link: http://lkml.kernel.org/r/1418243031-20367-3-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

perf/x86/intel/uncore: Make sure only uncore events are collected

2015-01-16T14:59:34Z

commit af91568e762d04931dcbdd6bef4655433d8b9418 upstream. The uncore_collect_events functions assumes that event group might contain only uncore events which is wrong, because it might contain any type of events. This bug leads to uncore framework touching 'not' uncore events, which could end up all sorts of bugs. One was triggered by Vince's perf fuzzer, when the uncore code touched breakpoint event private event space as if it was uncore event and caused BUG: BUG: unable to handle kernel paging request at ffffffff82822068 IP: [] uncore_assign_events+0x188/0x250 ... The code in uncore_assign_events() function was looking for event->hw.idx data while the event was initialized as a breakpoint with different members in event->hw union. This patch forces uncore_collect_events() to collect only uncore events. Reported-by: Vince Weaver Signed-off-by: Jiri Olsa Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Yan, Zheng Link: http://lkml.kernel.org/r/1418243031-20367-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

Btrfs: don't delay inode ref updates during log replay

2015-01-16T14:59:34Z

commit 6f8960541b1eb6054a642da48daae2320fddba93 upstream. Commit 1d52c78afbb (Btrfs: try not to ENOSPC on log replay) added a check to skip delayed inode updates during log replay because it confuses the enospc code. But the delayed processing will end up ignoring delayed refs from log replay because the inode itself wasn't put through the delayed code. This can end up triggering a warning at commit time: WARNING: CPU: 2 PID: 778 at fs/btrfs/delayed-inode.c:1410 btrfs_assert_delayed_root_empty+0x32/0x34() Which is repeated for each commit because we never process the delayed inode ref update. The fix used here is to change btrfs_delayed_delete_inode_ref to return an error if we're currently in log replay. The caller will do the ref deletion immediately and everything will work properly. Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman