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2013-10-31Merge tag 'pm+acpi-3.12-late' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael J Wysocki: "Last-minute ACPI and power management fixes for 3.12 - Revert epoll and select commits related to the freezer, introduced during the 3.11 cycle, that cause mysterious user space breakage to occur during resume from suspend to RAM for multiple users of 32-bit x86 systems. Material for 3.11.y stable kernels. - Revert a recent ACPI-based PCI hotplug (ACPIPHP) commit that was part of boot problem fixes for one machine, but turns out to cause issues with hotplug on Thunderbolt chains with multiple devices. It also turns out to be unnecessary after another fix in the same area that went in later. From Mika Westerberg" * tag 'pm+acpi-3.12-late' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "ACPI / hotplug / PCI: Avoid doing too much for spurious notifies" Revert "select: use freezable blocking call" Revert "epoll: use freezable blocking call"
2013-10-31ALSA: fix oops in snd_pcm_info() caused by ASoC DPCMRussell King
Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = d5300000 [00000008] *pgd=0d265831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT ARM CPU: 0 PID: 2295 Comm: vlc Not tainted 3.11.0+ #755 task: dee74800 ti: e213c000 task.ti: e213c000 PC is at snd_pcm_info+0xc8/0xd8 LR is at 0x30232065 pc : [<c031b52c>] lr : [<30232065>] psr: a0070013 sp : e213dea8 ip : d81cb0d0 fp : c05f7678 r10: c05f7770 r9 : fffffdfd r8 : 00000000 r7 : d8a968a8 r6 : d8a96800 r5 : d8a96200 r4 : d81cb000 r3 : 00000000 r2 : d81cb000 r1 : 00000001 r0 : d8a96200 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 15300019 DAC: 00000015 Process vlc (pid: 2295, stack limit = 0xe213c248) [<c031b52c>] (snd_pcm_info) from [<c031b570>] (snd_pcm_info_user+0x34/0x9c) [<c031b570>] (snd_pcm_info_user) from [<c03164a4>] (snd_pcm_control_ioctl+0x274/0x280) [<c03164a4>] (snd_pcm_control_ioctl) from [<c0311458>] (snd_ctl_ioctl+0xc0/0x55c) [<c0311458>] (snd_ctl_ioctl) from [<c00eca84>] (do_vfs_ioctl+0x80/0x31c) [<c00eca84>] (do_vfs_ioctl) from [<c00ecd5c>] (SyS_ioctl+0x3c/0x60) [<c00ecd5c>] (SyS_ioctl) from [<c000e500>] (ret_fast_syscall+0x0/0x48) Code: e1a00005 e59530dc e3a01001 e1a02004 (e5933008) ---[ end trace cb3d9bdb8dfefb3c ]--- This is provoked when the ASoC front end is open along with its backend, (which causes the backend to have a runtime assigned to it) and then the SNDRV_CTL_IOCTL_PCM_INFO is requested for the (visible) backend device. Resolve this by ensuring that ASoC internal backend devices are not visible to userspace, just as the commentry for snd_pcm_new_internal() says it should be. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Mark Brown <broonie@linaro.org> Cc: <stable@vger.kernel.org> [v3.4+] Signed-off-by: Takashi Iwai <tiwai@suse.de>
2013-10-31MIPS: ralink: fix return value check in rt_timer_probe()Wei Yongjun
In case of error, the function devm_request_and_ioremap() returns NULL pointer not ERR_PTR(). Fix it by using devm_ioremap_resource() instead of devm_request_and_ioremap(). Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: John Crispin <blogic@openwrt.org> Cc: grant.likely@linaro.org Cc: rob.herring@calxeda.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6098/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-31hung_task debugging: Add tracepoint to report the hangOleg Nesterov
Currently check_hung_task() prints a warning if it detects the problem, but it is not convenient to watch the system logs if user-space wants to be notified about the hang. Add the new trace_sched_process_hang() into check_hung_task(), this way a user-space monitor can easily wait for the hang and potentially resolve a problem. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Dave Sullivan <dsulliva@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20131019161828.GA7439@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-31Input: ALPS - add support for model found on Dell XT2Yunkang Tang
This patch adds support for touchpad found on Dell XT2. It's a dual device with device ID: 73, 00, 14, that comply with "ALPS_PROTO_V2". Signed-off-by: Yunkang Tang <yunkang.tang@cn.alps.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2013-10-31Merge branch 'drm-fixes-3.12' of git://people.freedesktop.org/~agd5f/linux ↵Dave Airlie
into drm-fixes Just a few small fixes for radeon (audio regression fix, stability fix, and an endian bug noticed by coverity). * 'drm-fixes-3.12' of git://people.freedesktop.org/~agd5f/linux: drm/radeon/dpm: fix incompatible casting on big endian drm/radeon: disable bapm on KB drm/radeon: use sw CTS/N values for audio on DCE4+
2013-10-30Merge branch 'akpm' (fixes from Andrew Morton)Linus Torvalds
Merge three fixes from Andrew Morton. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: memcg: use __this_cpu_sub() to dec stats to avoid incorrect subtrahend casting percpu: fix this_cpu_sub() subtrahend casting for unsigneds mm/pagewalk.c: fix walk_page_range() access of wrong PTEs
2013-10-30memcg: use __this_cpu_sub() to dec stats to avoid incorrect subtrahend castingGreg Thelen
As of commit 3ea67d06e467 ("memcg: add per cgroup writeback pages accounting") memcg counter errors are possible when moving charged memory to a different memcg. Charge movement occurs when processing writes to memory.force_empty, moving tasks to a memcg with memcg.move_charge_at_immigrate=1, or memcg deletion. An example showing error after memory.force_empty: $ cd /sys/fs/cgroup/memory $ mkdir x $ rm /data/tmp/file $ (echo $BASHPID >> x/tasks && exec mmap_writer /data/tmp/file 1M) & [1] 13600 $ grep ^mapped x/memory.stat mapped_file 1048576 $ echo 13600 > tasks $ echo 1 > x/memory.force_empty $ grep ^mapped x/memory.stat mapped_file 4503599627370496 mapped_file should end with 0. 4503599627370496 == 0x10,0000,0000,0000 == 0x100,0000,0000 pages 1048576 == 0x10,0000 == 0x100 pages This issue only affects the source memcg on 64 bit machines; the destination memcg counters are correct. So the rmdir case is not too important because such counters are soon disappearing with the entire memcg. But the memcg.force_empty and memory.move_charge_at_immigrate=1 cases are larger problems as the bogus counters are visible for the (possibly long) remaining life of the source memcg. The problem is due to memcg use of __this_cpu_from(.., -nr_pages), which is subtly wrong because it subtracts the unsigned int nr_pages (either -1 or -512 for THP) from a signed long percpu counter. When nr_pages=-1, -nr_pages=0xffffffff. On 64 bit machines stat->count[idx] is signed 64 bit. So memcg's attempt to simply decrement a count (e.g. from 1 to 0) boils down to: long count = 1 unsigned int nr_pages = 1 count += -nr_pages /* -nr_pages == 0xffff,ffff */ count is now 0x1,0000,0000 instead of 0 The fix is to subtract the unsigned page count rather than adding its negation. This only works once "percpu: fix this_cpu_sub() subtrahend casting for unsigneds" is applied to fix this_cpu_sub(). Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30percpu: fix this_cpu_sub() subtrahend casting for unsignedsGreg Thelen
this_cpu_sub() is implemented as negation and addition. This patch casts the adjustment to the counter type before negation to sign extend the adjustment. This helps in cases where the counter type is wider than an unsigned adjustment. An alternative to this patch is to declare such operations unsupported, but it seemed useful to avoid surprises. This patch specifically helps the following example: unsigned int delta = 1 preempt_disable() this_cpu_write(long_counter, 0) this_cpu_sub(long_counter, delta) preempt_enable() Before this change long_counter on a 64 bit machine ends with value 0xffffffff, rather than 0xffffffffffffffff. This is because this_cpu_sub(pcp, delta) boils down to this_cpu_add(pcp, -delta), which is basically: long_counter = 0 + 0xffffffff Also apply the same cast to: __this_cpu_sub() __this_cpu_sub_return() this_cpu_sub_return() All percpu_test.ko passes, especially the following cases which previously failed: l -= ui_one; __this_cpu_sub(long_counter, ui_one); CHECK(l, long_counter, -1); l -= ui_one; this_cpu_sub(long_counter, ui_one); CHECK(l, long_counter, -1); CHECK(l, long_counter, 0xffffffffffffffff); ul -= ui_one; __this_cpu_sub(ulong_counter, ui_one); CHECK(ul, ulong_counter, -1); CHECK(ul, ulong_counter, 0xffffffffffffffff); ul = this_cpu_sub_return(ulong_counter, ui_one); CHECK(ul, ulong_counter, 2); ul = __this_cpu_sub_return(ulong_counter, ui_one); CHECK(ul, ulong_counter, 1); Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30mm/pagewalk.c: fix walk_page_range() access of wrong PTEsChen LinX
When walk_page_range walk a memory map's page tables, it'll skip VM_PFNMAP area, then variable 'next' will to assign to vma->vm_end, it maybe larger than 'end'. In next loop, 'addr' will be larger than 'next'. Then in /proc/XXXX/pagemap file reading procedure, the 'addr' will growing forever in pagemap_pte_range, pte_to_pagemap_entry will access the wrong pte. BUG: Bad page map in process procrank pte:8437526f pmd:785de067 addr:9108d000 vm_flags:00200073 anon_vma:f0d99020 mapping: (null) index:9108d CPU: 1 PID: 4974 Comm: procrank Tainted: G B W O 3.10.1+ #1 Call Trace: dump_stack+0x16/0x18 print_bad_pte+0x114/0x1b0 vm_normal_page+0x56/0x60 pagemap_pte_range+0x17a/0x1d0 walk_page_range+0x19e/0x2c0 pagemap_read+0x16e/0x200 vfs_read+0x84/0x150 SyS_read+0x4a/0x80 syscall_call+0x7/0xb Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Signed-off-by: Chen LinX <linx.z.chen@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> [3.10.x+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30mm: list_lru: fix almost infinite loop causing effective livelockRussell King
I've seen a fair number of issues with kswapd and other processes appearing to get stuck in v3.12-rc. Using sysrq-p many times seems to indicate that it gets stuck somewhere in list_lru_walk_node(), called from prune_icache_sb() and super_cache_scan(). I never seem to be able to trigger a calltrace for functions above that point. So I decided to add the following to super_cache_scan(): @@ -81,10 +81,14 @@ static unsigned long super_cache_scan(struct shrinker *shrink, inodes = list_lru_count_node(&sb->s_inode_lru, sc->nid); dentries = list_lru_count_node(&sb->s_dentry_lru, sc->nid); total_objects = dentries + inodes + fs_objects + 1; +printk("%s:%u: %s: dentries %lu inodes %lu total %lu\n", current->comm, current->pid, __func__, dentries, inodes, total_objects); /* proportion the scan between the caches */ dentries = mult_frac(sc->nr_to_scan, dentries, total_objects); inodes = mult_frac(sc->nr_to_scan, inodes, total_objects); +printk("%s:%u: %s: dentries %lu inodes %lu\n", current->comm, current->pid, __func__, dentries, inodes); +BUG_ON(dentries == 0); +BUG_ON(inodes == 0); /* * prune the dcache first as the icache is pinned by it, then @@ -99,7 +103,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink, freed += sb->s_op->free_cached_objects(sb, fs_objects, sc->nid); } - +printk("%s:%u: %s: dentries %lu inodes %lu freed %lu\n", current->comm, current->pid, __func__, dentries, inodes, freed); drop_super(sb); return freed; } and shortly thereafter, having applied some pressure, I got this: update-apt-xapi:1616: super_cache_scan: dentries 25632 inodes 2 total 25635 update-apt-xapi:1616: super_cache_scan: dentries 1023 inodes 0 ------------[ cut here ]------------ Kernel BUG at c0101994 [verbose debug info unavailable] Internal error: Oops - BUG: 0 [#3] SMP ARM Modules linked in: fuse rfcomm bnep bluetooth hid_cypress CPU: 0 PID: 1616 Comm: update-apt-xapi Tainted: G D 3.12.0-rc7+ #154 task: daea1200 ti: c3bf8000 task.ti: c3bf8000 PC is at super_cache_scan+0x1c0/0x278 LR is at trace_hardirqs_on+0x14/0x18 Process update-apt-xapi (pid: 1616, stack limit = 0xc3bf8240) ... Backtrace: (super_cache_scan) from [<c00cd69c>] (shrink_slab+0x254/0x4c8) (shrink_slab) from [<c00d09a0>] (try_to_free_pages+0x3a0/0x5e0) (try_to_free_pages) from [<c00c59cc>] (__alloc_pages_nodemask+0x5) (__alloc_pages_nodemask) from [<c00e07c0>] (__pte_alloc+0x2c/0x13) (__pte_alloc) from [<c00e3a70>] (handle_mm_fault+0x84c/0x914) (handle_mm_fault) from [<c001a4cc>] (do_page_fault+0x1f0/0x3bc) (do_page_fault) from [<c001a7b0>] (do_translation_fault+0xac/0xb8) (do_translation_fault) from [<c000840c>] (do_DataAbort+0x38/0xa0) (do_DataAbort) from [<c00133f8>] (__dabt_usr+0x38/0x40) Notice that we had a very low number of inodes, which were reduced to zero my mult_frac(). Now, prune_icache_sb() calls list_lru_walk_node() passing that number of inodes (0) into that as the number of objects to scan: long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan, int nid) { LIST_HEAD(freeable); long freed; freed = list_lru_walk_node(&sb->s_inode_lru, nid, inode_lru_isolate, &freeable, &nr_to_scan); which does: unsigned long list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate, void *cb_arg, unsigned long *nr_to_walk) { struct list_lru_node *nlru = &lru->node[nid]; struct list_head *item, *n; unsigned long isolated = 0; spin_lock(&nlru->lock); restart: list_for_each_safe(item, n, &nlru->list) { enum lru_status ret; /* * decrement nr_to_walk first so that we don't livelock if we * get stuck on large numbesr of LRU_RETRY items */ if (--(*nr_to_walk) == 0) break; So, if *nr_to_walk was zero when this function was entered, that means we're wanting to operate on (~0UL)+1 objects - which might as well be infinite. Clearly this is not correct behaviour. If we think about the behaviour of this function when *nr_to_walk is 1, then clearly it's wrong - we decrement first and then test for zero - which results in us doing nothing at all. A post-decrement would give the desired behaviour - we'd try to walk one object and one object only if *nr_to_walk were one. It also gives the correct behaviour for zero - we exit at this point. Fixes: 5cedf721a7cd ("list_lru: fix broken LRU_RETRY behaviour") Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> [ Modified to make sure we never underflow the count: this function gets called in a loop, so the 0 -> ~0ul transition is dangerous - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30Merge tag 'tty-3.12-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull serial fixes from Greg KH: "Here are 3 tiny fixes that are needed for 3.12-final for some serial drivers. One of them is a revert of a broken patch, and two others are fixes for reported bugs. All of these have been in linux-next for a while, I forgot I had not sent them to you yet, my fault" (Actually, Greg, you _had_ sent two of the three, so this pulls in just one actual new fix) * tag 'tty-3.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty/serial: at91: fix uart/usart selection for older products
2013-10-30Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm fixes from Dave Airlie: "Mainly Intel regression fixes and quirks, along with a simple one liner to fix rendernodes ioctl access (off by default, but testers want to test it)" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm: allow DRM_IOCTL_VERSION on render-nodes drm/i915: Fix the PPT fdi lane bifurcate state handling on ivb drm/i915: No LVDS hardware on Intel D410PT and D425KT drm/i915/dp: workaround BIOS eDP bpp clamping issue drm/i915: Add HSW CRT output readout support drm/i915: Add support for pipe_bpp readout
2013-10-30Merge tag 'sound-3.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "A few small HD-audio regression fixes, mostly for stable kernels, too" * tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: hda - Fix silent headphone on Thinkpads with AD1984A codec ALSA: hda - Add missing initial vmaster hook at build_controls callback ALSA: hda - Fix unbalanced runtime PM refcount after S3/S4
2013-10-30Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Fixes for the 3.12 debugfs problem - removing the duplicate directory name, and using a better the error code" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: use a more sensible error number when debugfs directory creation fails KVM: Fix modprobe failure for kvm_intel/kvm_amd
2013-10-30Staging: sb105x: info leak in mp_get_count()Dan Carpenter
The icount.reserved[] array isn't initialized so it leaks stack information to userspace. Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30Staging: bcm: info leak in ioctlDan Carpenter
The DevInfo.u32Reserved[] array isn't initialized so it leaks kernel information to user space. Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30staging: wlags49_h2: buffer overflow setting station nameDan Carpenter
We need to check the length parameter before doing the memcpy(). I've actually changed it to strlcpy() as well so that it's NUL terminated. You need CAP_NET_ADMIN to trigger these so it's not the end of the world. Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30aacraid: missing capable() check in compat ioctlDan Carpenter
In commit d496f94d22d1 ('[SCSI] aacraid: fix security weakness') we added a check on CAP_SYS_RAWIO to the ioctl. The compat ioctls need the check as well. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30staging: ozwpan: prevent overflow in oz_cdev_write()Dan Carpenter
We need to check "count" so we don't overflow the ei->data buffer. Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30uml: check length in exitcode_proc_write()Dan Carpenter
We don't cap the size of buffer from the user so we could write past the end of the array here. Only root can write to this file. Reported-by: Nico Golde <nico@ngolde.de> Reported-by: Fabian Yamaguchi <fabs@goesec.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30Merge tag 'asoc-fix-v3.12-rc7' of ↵Takashi Iwai
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus ASoC: Fixes for v3.12 A few of the Coverity fixes from Takashi, one of which (the wm_hubs one) is particularly noticable.
2013-10-30Merge remote-tracking branch 'asoc/fix/wm8994' into asoc-linusMark Brown
2013-10-30ASoC: wm_hubs: Add missing break in hp_supply_event()Takashi Iwai
Spotted by coverity CID 115170. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Mark Brown <broonie@linaro.org> Cc: stable@vger.kernel.org
2013-10-30MIPS: malta: Fix GIC interrupt offsetsMarkos Chandras
The GIC interrupt offsets are calculated based on the value of NR_CPUS. However, this is wrong because NR_CPUS may or may not contain the real number of the actual cpus present in the system. We fix that by using the 'nr_cpu_ids' variable which contains the real number of cpus in the system. Previously, an MT core (eg with 8 VPEs) will fail to boot if NR_CPUS was > 8 with the following errors: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/irq/chip.c:670 __irq_set_handler+0x15c/0x164() Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.12.0-rc5-00087-gced5633 5 Stack : 00000006 00000004 00000000 00000000 00000000 00000000 807a4f36 00000053 807a0000 00000000 80173218 80565aa8 00000000 00000000 00000000 0000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 0000000 00000000 00000000 00000000 8054fd00 8054fd94 80500514 805657a7 8016eb4 807a0000 80500514 00000000 00000000 80565aa8 8079a5d8 80565766 8054fd0 ... Call Trace: [<801098c0>] show_stack+0x64/0x7c [<8049c6b0>] dump_stack+0x64/0x84 [<8012efc4>] warn_slowpath_common+0x84/0xb4 [<8012f00c>] warn_slowpath_null+0x18/0x24 [<80173218>] __irq_set_handler+0x15c/0x164 [<80587cf4>] arch_init_ipiirq+0x2c/0x3c [<805880c8>] arch_init_irq+0x3c4/0x4bc [<80588e28>] init_IRQ+0x3c/0x50 [<805847e8>] start_kernel+0x230/0x3d8 ---[ end trace 4eaa2a86a8e2da26 ]--- This is now fixed and the Malta board can boot with any NR_CPUS value which also helps supporting more processors in a single kernel binary. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6091/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-30Revert "ACPI / hotplug / PCI: Avoid doing too much for spurious notifies"Mika Westerberg
Commit 2dc4128 (ACPI / hotplug / PCI: Avoid doing too much for spurious notifies) changed the enable_slot() to check return value of pci_scan_slot() and if it is zero return early from the function. It means that there were no new devices in this particular slot. However, if a device appeared deeper in the hierarchy the code now ignores it causing things like Thunderbolt chaining fail to recognize new devices. The problem with Alex Williamson's machine was solved with commit a47d8c8 (ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks) and hence we should be able to restore the original functionality that we always rescan on bus check notification. On a device check notification we still check what acpiphp_rescan_slot() returns and on zero bail out early. Fixes: 2dc41281b1d1 (ACPI / hotplug / PCI: Avoid doing too much for spurious notifies) Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-30Revert "select: use freezable blocking call"Rafael J. Wysocki
This reverts commit 9745cdb36da8 (select: use freezable blocking call) that triggers problems during resume from suspend to RAM on Paul Bolle's 32-bit x86 machines. Paul says: Ever since I tried running (release candidates of) v3.11 on the two working i686s I still have lying around I ran into issues on resuming from suspend. Reverting 9745cdb36da8 (select: use freezable blocking call) resolves those issues. Resuming from suspend on i686 on (release candidates of) v3.11 and later triggers issues like: traps: systemd[1] general protection ip:b738e490 sp:bf882fc0 error:0 in libc-2.16.so[b731c000+1b0000] and traps: rtkit-daemon[552] general protection ip:804d6e5 sp:b6cb32f0 error:0 in rtkit-daemon[8048000+d000] Once I hit the systemd error I can only get out of the mess that the system is at that point by power cycling it. Since we are reverting another freezer-related change causing similar problems to happen, this one should be reverted as well. References: https://lkml.org/lkml/2013/10/29/583 Reported-by: Paul Bolle <pebolle@tiscali.nl> Fixes: 9745cdb36da8 (select: use freezable blocking call) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: 3.11+ <stable@vger.kernel.org> # 3.11+
2013-10-30Revert "epoll: use freezable blocking call"Rafael J. Wysocki
This reverts commit 1c441e921201 (epoll: use freezable blocking call) which is reported to cause user space memory corruption to happen after suspend to RAM. Since it appears to be extremely difficult to root cause this problem, it is best to revert the offending commit and try to address the original issue in a better way later. References: https://bugzilla.kernel.org/show_bug.cgi?id=61781 Reported-by: Natrio <natrio@list.ru> Reported-by: Jeff Pohlmeyer <yetanothergeek@gmail.com> Bisected-by: Leo Wolf <jclw@ymail.com> Fixes: 1c441e921201 (epoll: use freezable blocking call) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: 3.11+ <stable@vger.kernel.org> # 3.11+
2013-10-30ALSA: hda - Add a fixup for ASUS N76VZTakashi Iwai
ASUS N76VZ needs the same fixup as N56VZ for supporting the boost speaker. Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=846529 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2013-10-30KVM: use a more sensible error number when debugfs directory creation failsPaolo Bonzini
I don't know if this was due to cut and paste, or somebody was really using a D20 to pick the error code for kvm_init_debugfs as suggested by Linus (EFAULT is 14, so the possibility cannot be entirely ruled out). In any case, this patch fixes it. Reported-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30KVM: Fix modprobe failure for kvm_intel/kvm_amdTim Gardner
The x86 specific kvm init creates a new conflicting debugfs directory which causes modprobe issues with kvm_intel and kvm_amd. For example, sudo modprobe kvm_amd modprobe: ERROR: could not insert 'kvm_amd': Bad address The simplest fix is to just rename the directory. The following KVM config options are set: CONFIG_KVM_GUEST=y CONFIG_KVM_DEBUG_FS=y CONFIG_HAVE_KVM=y CONFIG_HAVE_KVM_IRQCHIP=y CONFIG_HAVE_KVM_IRQ_ROUTING=y CONFIG_HAVE_KVM_EVENTFD=y CONFIG_KVM_APIC_ARCHITECTURE=y CONFIG_KVM_MMIO=y CONFIG_KVM_ASYNC_PF=y CONFIG_HAVE_KVM_MSI=y CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT=y CONFIG_KVM=m CONFIG_KVM_INTEL=m CONFIG_KVM_AMD=m CONFIG_KVM_DEVICE_ASSIGNMENT=y Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> [Change debugfs directory name. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-30drm: allow DRM_IOCTL_VERSION on render-nodesDavid Herrmann
DRM_IOCTL_VERSION is a reliable way to get the driver-name and version information. It's not related to the interface-version (SET_VERSION ioctl) so we can safely enable it on render-nodes. Note that gbm uses udev-BUSID to load the correct mesa driver. However, the VERSION ioctl should be the more reliable way to do this (in case we add new DRM-bus drivers which have no BUSID or similar). Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-10-30Merge tag 'drm-intel-fixes-2013-10-29' of ↵Dave Airlie
git://people.freedesktop.org/~danvet/drm-intel into drm-fixes Regression and warn fixes for i915. * tag 'drm-intel-fixes-2013-10-29' of git://people.freedesktop.org/~danvet/drm-intel: drm/i915: Fix the PPT fdi lane bifurcate state handling on ivb drm/i915: No LVDS hardware on Intel D410PT and D425KT drm/i915/dp: workaround BIOS eDP bpp clamping issue drm/i915: Add HSW CRT output readout support drm/i915: Add support for pipe_bpp readout
2013-10-29MIPS: Perf: Fix 74K cache mapDeng-Cheng Zhu
According to Software User's Manual, the event of last-level-cache read/write misses is mapped to even counters. Odd counters of that event number count miss cycles. Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6036/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-29Fix a few incorrectly checked [io_]remap_pfn_range() callsLinus Torvalds
Nico Golde reports a few straggling uses of [io_]remap_pfn_range() that really should use the vm_iomap_memory() helper. This trivially converts two of them to the helper, and comments about why the third one really needs to continue to use remap_pfn_range(), and adds the missing size check. Reported-by: Nico Golde <nico@ngolde.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org.
2013-10-29Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf tooling fixes from Ingo Molnar: "This contains five tooling fixes: - fix a remaining mmap2 assumption which resulted in perf top output breakage - fix mmap ring-buffer processing bug that corrupts data - fix for a severe python scripting memory leak - fix broken (and user-visible) -g option handling - fix stdio output The diffstat size is larger than what we'd like to see this late :-/" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Fixup mmap event consumption perf top: Split -G and --call-graph perf record: Split -g and --call-graph perf hists: Add color overhead for stdio output buffer perf tools: Fix up /proc/PID/maps parsing perf script python: Fix mem leak due to missing Py_DECREFs on dict entries
2013-10-29Kconfig: make KOBJECT_RELEASE debugging require timer debuggingLinus Torvalds
Without the timer debugging, the delayed kobject release will just result in undebuggable oopses if it triggers any latent bugs. That doesn't actually help debugging at all. So make DEBUG_KOBJECT_RELEASE depend on DEBUG_OBJECTS_TIMERS to avoid having people enable one without the other. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-29drm/i915: Fix the PPT fdi lane bifurcate state handling on ivbDaniel Vetter
Originally I've thought that this is leftover hw state dirt from the BIOS. But after way too much helpless flailing around on my part I've noticed that the actual bug is when we change the state of an already active pipe. For example when we change the fdi lines from 2 to 3 without switching off outputs in-between we'll never see the crucial on->off transition in the ->modeset_global_resources hook the current logic relies on. Patch version 2 got this right by instead also checking whether the pipe is indeed active. But that in turn broke things when pipes have been turned off through dpms since the bifurcate enabling is done in the ->crtc_mode_set callback. To address this issues discussed with Ville in the patch review move the setting of the bifurcate bit into the ->crtc_enable hook. That way we won't wreak havoc with this state when userspace puts all other outputs into dpms off state. This also moves us forward with our overall goal to unify the modeset and dpms on paths (which we need to have to allow runtime pm in the dpms off state). Unfortunately this requires us to move the bifurcate helpers around a bit. Also update the commit message, I've misanalyzed the bug rather badly. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70507 Tested-by: Jan-Michael Brummer <jan.brummer@tabos.org> Cc: stable@vger.kernel.org Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-10-29sched: Avoid throttle_cfs_rq() racing with period_timer stoppingBen Segall
throttle_cfs_rq() doesn't check to make sure that period_timer is running, and while update_curr/assign_cfs_runtime does, a concurrently running period_timer on another cpu could cancel itself between this cpu's update_curr and throttle_cfs_rq(). If there are no other cfs_rqs running in the tg to restart the timer, this causes the cfs_rq to be stranded forever. Fix this by calling __start_cfs_bandwidth() in throttle if the timer is inactive. (Also add some sched_debug lines for cfs_bandwidth.) Tested: make a run/sleep task in a cgroup, loop switching the cgroup between 1ms/100ms quota and unlimited, checking for timer_active=0 and throttled=1 as a failure. With the throttle_cfs_rq() change commented out this fails, with the full patch it passes. Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: pjt@google.com Link: http://lkml.kernel.org/r/20131016181632.22647.84174.stgit@sword-of-the-dawn.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29sched: Guarantee new group-entities always have weightPaul Turner
Currently, group entity load-weights are initialized to zero. This admits some races with respect to the first time they are re-weighted in earlty use. ( Let g[x] denote the se for "g" on cpu "x". ) Suppose that we have root->a and that a enters a throttled state, immediately followed by a[0]->t1 (the only task running on cpu[0]) blocking: put_prev_task(group_cfs_rq(a[0]), t1) put_prev_entity(..., t1) check_cfs_rq_runtime(group_cfs_rq(a[0])) throttle_cfs_rq(group_cfs_rq(a[0])) Then, before unthrottling occurs, let a[0]->b[0]->t2 wake for the first time: enqueue_task_fair(rq[0], t2) enqueue_entity(group_cfs_rq(b[0]), t2) enqueue_entity_load_avg(group_cfs_rq(b[0]), t2) account_entity_enqueue(group_cfs_ra(b[0]), t2) update_cfs_shares(group_cfs_rq(b[0])) < skipped because b is part of a throttled hierarchy > enqueue_entity(group_cfs_rq(a[0]), b[0]) ... We now have b[0] enqueued, yet group_cfs_rq(a[0])->load.weight == 0 which violates invariants in several code-paths. Eliminate the possibility of this by initializing group entity weight. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131016181627.22647.47543.stgit@sword-of-the-dawn.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29sched: Fix hrtimer_cancel()/rq->lock deadlockBen Segall
__start_cfs_bandwidth calls hrtimer_cancel while holding rq->lock, waiting for the hrtimer to finish. However, if sched_cfs_period_timer runs for another loop iteration, the hrtimer can attempt to take rq->lock, resulting in deadlock. Fix this by ensuring that cfs_b->timer_active is cleared only if the _latest_ call to do_sched_cfs_period_timer is returning as idle. Then __start_cfs_bandwidth can just call hrtimer_try_to_cancel and wait for that to succeed or timer_active == 1. Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: pjt@google.com Link: http://lkml.kernel.org/r/20131016181622.22647.16643.stgit@sword-of-the-dawn.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29sched: Fix cfs_bandwidth misuse of hrtimer_expires_remainingBen Segall
hrtimer_expires_remaining does not take internal hrtimer locks and thus must be guarded against concurrent __hrtimer_start_range_ns (but returning HRTIMER_RESTART is safe). Use cfs_b->lock to make it safe. Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: pjt@google.com Link: http://lkml.kernel.org/r/20131016181617.22647.73829.stgit@sword-of-the-dawn.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29sched: Fix race on toggling cfs_bandwidth_usedBen Segall
When we transition cfs_bandwidth_used to false, any currently throttled groups will incorrectly return false from cfs_rq_throttled. While tg_set_cfs_bandwidth will unthrottle them eventually, currently running code (including at least dequeue_task_fair and distribute_cfs_runtime) will cause errors. Fix this by turning off cfs_bandwidth_used only after unthrottling all cfs_rqs. Tested: toggle bandwidth back and forth on a loaded cgroup. Caused crashes in minutes without the patch, hasn't crashed with it. Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: pjt@google.com Link: http://lkml.kernel.org/r/20131016181611.22647.80365.stgit@sword-of-the-dawn.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf/x86: Fix NMI measurementsPeter Zijlstra
OK, so what I'm actually seeing on my WSM is that sched/clock.c is 'broken' for the purpose we're using it for. What triggered it is that my WSM-EP is broken :-( [ 0.001000] tsc: Fast TSC calibration using PIT [ 0.002000] tsc: Detected 2533.715 MHz processor [ 0.500180] TSC synchronization [CPU#0 -> CPU#6]: [ 0.505197] Measured 3 cycles TSC warp between CPUs, turning off TSC clock. [ 0.004000] tsc: Marking TSC unstable due to check_tsc_sync_source failed For some reason it consistently detects TSC skew, even though NHM+ should have a single clock domain for 'reasonable' systems. This marks sched_clock_stable=0, which means that we do fancy stuff to try and get a 'sane' clock. Part of this fancy stuff relies on the tick, clearly that's gone when NOHZ=y. So for idle cpus time gets stuck, until it either wakes up or gets kicked by another cpu. While this is perfectly fine for the scheduler -- it only cares about actually running stuff, and when we're running stuff we're obviously not idle. This does somewhat break down for perf which can trigger events just fine on an otherwise idle cpu. So I've got NMIs get get 'measured' as taking ~1ms, which actually don't last nearly that long: <idle>-0 [013] d.h. 886.311970: rcu_nmi_enter <-do_nmi ... <idle>-0 [013] d.h. 886.311997: perf_sample_event_took: HERE!!! : 1040990 So ftrace (which uses sched_clock(), not the fancy bits) only sees ~27us, but we measure ~1ms !! Now since all this measurement stuff lives in x86 code, we can actually fix it. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: mingo@kernel.org Cc: dave.hansen@linux.intel.com Cc: eranian@google.com Cc: Don Zickus <dzickus@redhat.com> Cc: jmario@redhat.com Cc: acme@infradead.org Link: http://lkml.kernel.org/r/20131017133350.GG3364@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf: Fix perf ring buffer memory orderingPeter Zijlstra
The PPC64 people noticed a missing memory barrier and crufty old comments in the perf ring buffer code. So update all the comments and add the missing barrier. When the architecture implements local_t using atomic_long_t there will be double barriers issued; but short of introducing more conditional barrier primitives this is the best we can do. Reported-by: Victor Kaplansky <victork@il.ibm.com> Tested-by: Victor Kaplansky <victork@il.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: michael@ellerman.id.au Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: anton@samba.org Cc: benh@kernel.crashing.org Link: http://lkml.kernel.org/r/20131025173749.GG19466@laptop.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29mm: Account for a THP NUMA hinting update as one PTE updateMel Gorman
A THP PMD update is accounted for as 512 pages updated in vmstat. This is large difference when estimating the cost of automatic NUMA balancing and can be misleading when comparing results that had collapsed versus split THP. This patch addresses the accounting issue. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29mm: Close races between THP migration and PMD numa clearingMel Gorman
THP migration uses the page lock to guard against parallel allocations but there are cases like this still open Task A Task B --------------------- --------------------- do_huge_pmd_numa_page do_huge_pmd_numa_page lock_page mpol_misplaced == -1 unlock_page goto clear_pmdnuma lock_page mpol_misplaced == 2 migrate_misplaced_transhuge pmd = pmd_mknonnuma set_pmd_at During hours of testing, one crashed with weird errors and while I have no direct evidence, I suspect something like the race above happened. This patch extends the page lock to being held until the pmd_numa is cleared to prevent migration starting in parallel while the pmd_numa is being cleared. It also flushes the old pmd entry and orders pagetable insertion before rmap insertion. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-9-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29mm: numa: Sanitize task_numa_fault() callsitesMel Gorman
There are three callers of task_numa_fault(): - do_huge_pmd_numa_page(): Accounts against the current node, not the node where the page resides, unless we migrated, in which case it accounts against the node we migrated to. - do_numa_page(): Accounts against the current node, not the node where the page resides, unless we migrated, in which case it accounts against the node we migrated to. - do_pmd_numa_page(): Accounts not at all when the page isn't migrated, otherwise accounts against the node we migrated towards. This seems wrong to me; all three sites should have the same sementaics, furthermore we should accounts against where the page really is, we already know where the task is. So modify all three sites to always account; we did after all receive the fault; and always account to where the page is after migration, regardless of success. They all still differ on when they clear the PTE/PMD; ideally that would get sorted too. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29mm: Prevent parallel splits during THP migrationMel Gorman
THP migrations are serialised by the page lock but on its own that does not prevent THP splits. If the page is split during THP migration then the pmd_same checks will prevent page table corruption but the unlock page and other fix-ups potentially will cause corruption. This patch takes the anon_vma lock to prevent parallel splits during migration. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-7-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29mm: Wait for THP migrations to complete during NUMA hinting faultsMel Gorman
The locking for migrating THP is unusual. While normal page migration prevents parallel accesses using a migration PTE, THP migration relies on a combination of the page_table_lock, the page lock and the existance of the NUMA hinting PTE to guarantee safety but there is a bug in the scheme. If a THP page is currently being migrated and another thread traps a fault on the same page it checks if the page is misplaced. If it is not, then pmd_numa is cleared. The problem is that it checks if the page is misplaced without holding the page lock meaning that the racing thread can be migrating the THP when the second thread clears the NUMA bit and faults a stale page. This patch checks if the page is potentially being migrated and stalls using the lock_page if it is potentially being migrated before checking if the page is misplaced or not. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-6-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>