- 06 Nov, 2013 17 commits
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John Stultz authored
After adding lockdep support to seqlock/seqcount structures, I started seeing the following warning: [ 1.070907] ====================================================== [ 1.072015] [ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ] [ 1.073181] 3.11.0+ #67 Not tainted [ 1.073801] ------------------------------------------------------ [ 1.074882] kworker/u4:2/708 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 1.076088] (&p->mems_allowed_seq){+.+...}, at: [<ffffffff81187d7f>] new_slab+0x5f/0x280 [ 1.077572] [ 1.077572] and this task is already holding: [ 1.078593] (&(&q->__queue_lock)->rlock){..-...}, at: [<ffffffff81339f03>] blk_execute_rq_nowait+0x53/0xf0 [ 1.080042] which would create a new lock dependency: [ 1.080042] (&(&q->__queue_lock)->rlock){..-...} -> (&p->mems_allowed_seq){+.+...} [ 1.080042] [ 1.080042] but this new dependency connects a SOFTIRQ-irq-safe lock: [ 1.080042] (&(&q->__queue_lock)->rlock){..-...} [ 1.080042] ... which became SOFTIRQ-irq-safe at: [ 1.080042] [<ffffffff810ec179>] __lock_acquire+0x5b9/0x1db0 [ 1.080042] [<ffffffff810edfe5>] lock_acquire+0x95/0x130 [ 1.080042] [<ffffffff818968a1>] _raw_spin_lock+0x41/0x80 [ 1.080042] [<ffffffff81560c9e>] scsi_device_unbusy+0x7e/0xd0 [ 1.080042] [<ffffffff8155a612>] scsi_finish_command+0x32/0xf0 [ 1.080042] [<ffffffff81560e91>] scsi_softirq_done+0xa1/0x130 [ 1.080042] [<ffffffff8133b0f3>] blk_done_softirq+0x73/0x90 [ 1.080042] [<ffffffff81095dc0>] __do_softirq+0x110/0x2f0 [ 1.080042] [<ffffffff81095fcd>] run_ksoftirqd+0x2d/0x60 [ 1.080042] [<ffffffff810bc506>] smpboot_thread_fn+0x156/0x1e0 [ 1.080042] [<ffffffff810b3916>] kthread+0xd6/0xe0 [ 1.080042] [<ffffffff818980ac>] ret_from_fork+0x7c/0xb0 [ 1.080042] [ 1.080042] to a SOFTIRQ-irq-unsafe lock: [ 1.080042] (&p->mems_allowed_seq){+.+...} [ 1.080042] ... which became SOFTIRQ-irq-unsafe at: [ 1.080042] ... [<ffffffff810ec1d3>] __lock_acquire+0x613/0x1db0 [ 1.080042] [<ffffffff810edfe5>] lock_acquire+0x95/0x130 [ 1.080042] [<ffffffff810b3df2>] kthreadd+0x82/0x180 [ 1.080042] [<ffffffff818980ac>] ret_from_fork+0x7c/0xb0 [ 1.080042] [ 1.080042] other info that might help us debug this: [ 1.080042] [ 1.080042] Possible interrupt unsafe locking scenario: [ 1.080042] [ 1.080042] CPU0 CPU1 [ 1.080042] ---- ---- [ 1.080042] lock(&p->mems_allowed_seq); [ 1.080042] local_irq_disable(); [ 1.080042] lock(&(&q->__queue_lock)->rlock); [ 1.080042] lock(&p->mems_allowed_seq); [ 1.080042] <Interrupt> [ 1.080042] lock(&(&q->__queue_lock)->rlock); [ 1.080042] [ 1.080042] *** DEADLOCK *** The issue stems from the kthreadd() function calling set_mems_allowed with irqs enabled. While its possibly unlikely for the actual deadlock to trigger, a fix is fairly simple: disable irqs before taking the mems_allowed_seq lock. Signed-off-by:John Stultz <john.stultz@linaro.org> Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Acked-by:
Li Zefan <lizefan@huawei.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-4-git-send-email-john.stultz@linaro.orgSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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John Stultz authored
Currently seqlocks and seqcounts don't support lockdep. After running across a seqcount related deadlock in the timekeeping code, I used a less-refined and more focused variant of this patch to narrow down the cause of the issue. This is a first-pass attempt to properly enable lockdep functionality on seqlocks and seqcounts. Since seqcounts are used in the vdso gettimeofday code, I've provided non-lockdep accessors for those needs. I've also handled one case where there were nested seqlock writers and there may be more edge cases. Comments and feedback would be appreciated! Signed-off-by:
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John Stultz authored
In order to enable lockdep on seqcount/seqlock structures, we must explicitly initialize any locks. The u64_stats_sync structure, uses a seqcount, and thus we need to introduce a u64_stats_init() function and use it to initialize the structure. This unfortunately adds a lot of fairly trivial initialization code to a number of drivers. But the benefit of ensuring correctness makes this worth while. Because these changes are required for lockdep to be enabled, and the changes are quite trivial, I've not yet split this patch out into 30-some separate patches, as I figured it would be better to get the various maintainers thoughts on how to best merge this change along with the seqcount lockdep enablement. Feedback would be appreciated! Signed-off-by:
Julian Anastasov <ja@ssi.bg> Signed-off-by:
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Peter Zijlstra authored
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Peter Zijlstra authored
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Peter Zijlstra authored
Notably: changed lib/rwsem* targets from lib- to obj-, no idea about the ramifications of that. Suggested-by:
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Peter Zijlstra authored
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Peter Zijlstra authored
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Peter Zijlstra authored
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Peter Zijlstra authored
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Peter Zijlstra authored
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Ingo Molnar authored
Conflicts: kernel/Makefile There are conflicts in kernel/Makefile due to file moving in the scheduler tree - resolve them. Signed-off-by: -
Peter Zijlstra authored
Completions already have their own header file: linux/completion.h Move the implementation out of kernel/sched/core.c and into its own file: kernel/sched/completion.c. Signed-off-by:
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Peter Zijlstra authored
For some reason only the wait part of the wait api lives in kernel/sched/wait.c and the wake part still lives in kernel/sched/core.c; ammend this. Signed-off-by:
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Peter Zijlstra authored
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Ingo Molnar authored
There are conflicts in lockdep.c due to RCU changes, and also the RCU tree changes kernel/Makefile - so pre-merge it to ease the moving of locking related .c files to kernel/locking/. Signed-off-by: -
Ingo Molnar authored
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- 03 Nov, 2013 3 commits
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Linus Torvalds authored
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git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds authored
Pull MIPS fixes from Ralf Baechle: "Three fixes across arch/mips with the most complex one being the GIC interrupt fix - at nine lines still not monster. I'm confident this are the final MIPS patches even if there should go for an rc8" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: ralink: fix return value check in rt_timer_probe() MIPS: malta: Fix GIC interrupt offsets MIPS: Perf: Fix 74K cache map
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Mathias Krause authored
Negative message lengths make no sense -- so don't do negative queue lenghts or identifier counts. Prevent them from getting negative. Also change the underlying data types to be unsigned to avoid hairy surprises with sign extensions in cases where those variables get evaluated in unsigned expressions with bigger data types, e.g size_t. In case a user still wants to have "unlimited" sizes she could just use INT_MAX instead. Signed-off-by:
Mathias Krause <minipli@googlemail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 02 Nov, 2013 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linuxLinus Torvalds authored
Pull ARM kallsyms fix from Rusty Russell: "Last minute perf unbreakage for ARM modules; spent a day in linux-next" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: scripts/kallsyms: filter symbols not in kernel address space
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Vineet Gupta authored
A vmalloc fault needs to sync up PGD/PTE entry from init_mm to current task's "active_mm". ARC vmalloc fault handler however was using mm. A vmalloc fault for non user task context (actually pre-userland, from init thread's open for /dev/console) caused the handler to deref NULL mm (for mm->pgd) The reasons it worked so far is amazing: 1. By default (!SMP), vmalloc fault handler uses a cached value of PGD. In SMP that MMU register is repurposed hence need for mm pointer deref. 2. In pre-3.12 SMP kernel, the problem triggering vmalloc didn't exist in pre-userland code path - it was introduced with commit 20bafb3d "n_tty: Move buffers into n_tty_data" Signed-off-by:
Vineet Gupta <vgupta@synopsys.com> Cc: Gilad Ben-Yossef <gilad@benyossef.com> Cc: Noam Camus <noamc@ezchip.com> Cc: stable@vger.kernel.org #3.10 and 3.11 Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by:
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- 01 Nov, 2013 18 commits
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Ming Lei authored
This patch uses CONFIG_PAGE_OFFSET to filter symbols which are not in kernel address space because these symbols are generally for generating code purpose and can't be run at kernel mode, so we needn't keep them in /proc/kallsyms. For example, on ARM there are some symbols which may be linked in relocatable code section, then perf can't parse symbols any more from /proc/kallsyms, this patch fixes the problem (introduced b9b32bf7) Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Michal Marek <mmarek@suse.cz> Signed-off-by:
Ming Lei <tom.leiming@gmail.com> Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au> Cc: stable@vger.kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Ingo Molnar: "Two fixes: - Fix 'NMI handler took too long to run' false positives [ Genuine NMI overhead speedups will come for v3.13, this commit only fixes a measurement bug ] - Fix perf ring-buffer missed barrier causing (rare) ring-buffer data corruption on ppc64" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix NMI measurements perf: Fix perf ring buffer memory ordering -
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usbLinus Torvalds authored
Pull USB fixes from Greg KH: "Here is a set of patches that revert all of the changes done to the pl2303 USB serial driver in the 3.12-rc timeframe, as it turns out they break some devices that work just fine on 3.11. As it's not a good idea to break working systems, drop them all and they will be reworked for future kernel versions such that there is no breakage. I've also included a MAINTAINERS update for the USB serial subsystem and a new device id for the ftdi_sio driver as well" * tag 'usb-3.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: USB: serial: ftdi_sio: add id for Z3X Box device USB: Maintainers change for usb serial drivers Revert "USB: pl2303: restrict the divisor based baud rate encoding method to the "HX" chip type" Revert "usb: pl2303: fix+improve the divsor based baud rate encoding method" Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method" Revert "usb: pl2303: remove 500000 baud from the list of standard baud rates" Revert "usb: pl2303: move the two baud rate encoding methods to separate functions" Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method" Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips" Revert "usb: pl2303: add two comments concerning the supported baud rates with HX chips" Revert "pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()" Revert "pl2303: improve the chip type information output on startup" Revert "pl2303: improve the chip type detection/distinction" Revert "USB: pl2303: distinguish between original and cloned HX chips"
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/soundLinus Torvalds authored
Pull more sound fixes from Takashi Iwai: "The fixes for random bugs that have been reported lately in the game: a few fixes in ASoC dpam and wm_hubs bugs spotted by Coverity, a one-liner HD-audio fixup, and a fix for Oops with DPCM. They are not so critically urgent bugs, but all small and safe" * tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: fix oops in snd_pcm_info() caused by ASoC DPCM ASoC: wm_hubs: Add missing break in hp_supply_event() ALSA: hda - Add a fixup for ASUS N76VZ ASoC: dapm: Return -ENOMEM in snd_soc_dapm_new_dai_widgets() ASoC: dapm: Fix source list debugfs outputs
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git://git.linaro.org/people/mturquette/linuxLinus Torvalds authored
Pull clock subsystem fixes from Mike Turquette. * tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mturquette/linux: clk: fixup argument order when setting VCO parameters clk: socfpga: Fix incorrect sdmmc clock name clk: armada-370: fix tclk frequencies clk: nomadik: set all timers to use 2.4 MHz TIMCLK
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Greg Thelen authored
When a memcg is deleted mem_cgroup_reparent_charges() moves charged memory to the parent memcg. As of v3.11-9444-g3ea67d06 "memcg: add per cgroup writeback pages accounting" there's bad pointer read. The goal was to check for counter underflow. The counter is a per cpu counter and there are two problems with the code: (1) per cpu access function isn't used, instead a naked pointer is used which easily causes oops. (2) the check doesn't sum all cpus Test: $ cd /sys/fs/cgroup/memory $ mkdir x $ echo 3 > /proc/sys/vm/drop_caches $ (echo $BASHPID >> x/tasks && exec cat) & [1] 7154 $ grep ^mapped x/memory.stat mapped_file 53248 $ echo 7154 > tasks $ rmdir x <OOPS> The fix is to remove the check. It's currently dangerous and isn't worth fixing it to use something expensive, such as percpu_counter_sum(), for each reparented page. __this_cpu_read() isn't enough to fix this because there's no guarantees of the current cpus count. The only guarantees is that the sum of all per-cpu counter is >= nr_pages. Fixes: 3ea67d06 ("memcg: add per cgroup writeback pages accounting") Reported-and-tested-by:
Flavio Leitner <fbl@redhat.com> Signed-off-by:
Greg Thelen <gthelen@google.com> Reviewed-by:
Sha Zhengju <handai.szj@taobao.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
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Алексей Крамаренко authored
Custom VID/PID for Z3X Box device, popular tool for cellphone flashing. Signed-off-by:
Alexey E. Kramarenko <alexeyk13@yandex.ru> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Greg KH authored
Johan has been conned^Wgracious in accepting the maintainership of the USB serial drivers, especially as he's been doing all of the real work for the past few years. At the same time, remove a bunch of old entries for USB serial drivers that don't make sense anymore, given that the developers are no longer around, and individual driver maintainerships for tiny things like this is pretty pointless. Acked-by:
Johan Hovold <jhovold@gmail.com> Signed-off-by:
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Greg Kroah-Hartman authored
This reverts commit b8bdad60. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Frank Schäfer <fschaefer.oss@googlemail.com> Acked-by:
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Greg Kroah-Hartman authored
This reverts commit 57ce61aa. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method" This reverts commit 75417d9f. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit b9208c72. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit e917ba01. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit b5c16c6a. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips" This reverts commit 61fa8d69. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit c23bda36. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit 73b583af. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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Greg Kroah-Hartman authored
This reverts commit a77a8c23. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by:
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