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2013-10-31mm/pagewalk.c: fix walk_page_range() access of wrong PTEsChen LinX1-1/+1
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 King1-1/+2
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 Torvalds1-7/+2
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 Torvalds7-54/+168
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 Torvalds3-4/+22
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 Torvalds2-2/+2
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 Carpenter1-1/+1
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 Carpenter1-0/+1
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 Carpenter1-3/+6
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 Carpenter1-0/+2
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 Carpenter1-0/+3
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 Carpenter1-1/+3
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 Iwai375-2263/+3280
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 Brown1-0/+1
2013-10-30ASoC: wm_hubs: Add missing break in hp_supply_event()Takashi Iwai1-0/+1
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 Chandras1-4/+5
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 Westerberg1-5/+1
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. Wysocki1-2/+1
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. Wysocki1-3/+1
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 Iwai1-0/+1
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 Bonzini1-1/+1
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 Gardner1-1/+1
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 Herrmann1-1/+1
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 Airlie6-53/+167
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
2013-10-30MIPS: Perf: Fix 74K cache mapDeng-Cheng Zhu1-2/+2
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 Torvalds3-49/+17
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.
2013-10-29uprobes: Teach uprobe_copy_process() to handle CLONE_VFORKOleg Nesterov3-5/+11
uprobe_copy_process() does nothing if the child shares ->mm with the forking process, but there is a special case: CLONE_VFORK. In this case it would be more correct to do dup_utask() but avoid dup_xol(). This is not that important, the child should not unwind its stack too much, this can corrupt the parent's stack, but at least we need this to allow to ret-probe __vfork() itself. Note: in theory, it would be better to check task_pt_regs(p)->sp instead of CLONE_VFORK, we need to dup_utask() if and only if the child can return from the function called by the parent. But this needs the arch-dependant helper, and I think that nobody actually does clone(same_stack, CLONE_VM). Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-10-29uprobes: Change uprobe_copy_process() to dup xol_areaOleg Nesterov1-0/+28
This finally fixes the serious bug in uretprobes: a forked child crashes if the parent called fork() with the pending ret probe. Trivial test-case: # perf probe -x /lib/libc.so.6 __fork%return # perf record -e probe_libc:__fork perl -le 'fork || print "OK"' (the child doesn't print "OK", it is killed by SIGSEGV) If the child returns from the probed function it actually returns to trampoline_vaddr, because it got the copy of parent's stack mangled by prepare_uretprobe() when the parent entered this func. It crashes because a) this address is not mapped and b) until the previous change it doesn't have the proper->return_instances info. This means that uprobe_copy_process() has to create xol_area which has the trampoline slot, and its vaddr should be equal to parent's xol_area->vaddr. Unfortunately, uprobe_copy_process() can not simply do __create_xol_area(child, xol_area->vaddr). This could actually work but perf_event_mmap() doesn't expect the usage of foreign ->mm. So we offload this to task_work_run(), and pass the argument via not yet used utask->vaddr. We know that this vaddr is fine for install_special_mapping(), the necessary hole was recently "created" by dup_mmap() which skips the parent's VM_DONTCOPY area, and nobody else could use the new mm. Unfortunately, this also means that we can not handle the errors properly, we obviously can not abort the already completed fork(). So we simply print the warning if GFP_KERNEL allocation (the only possible reason) fails. Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29uprobes: Change uprobe_copy_process() to dup return_instancesOleg Nesterov1-0/+43
uprobe_copy_process() assumes that the new child doesn't need ->utask, it should be allocated by demand. But this is not true if the forking task has the pending ret- probes, the child should report them as well and thus it needs the copy of parent's ->return_instances chain. Otherwise the child crashes when it returns from the probed function. Alternatively we could cleanup the child's stack, but this needs per-arch changes and this is not what we want. At least systemtap expects a .return in the child too. Note: this change alone doesn't fix the problem, see the next change. Reported-by: Martin Cermak <mcermak@redhat.com> Reported-by: David Smith <dsmith@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29uprobes: Teach __create_xol_area() to accept the predefined vaddrOleg Nesterov1-8/+12
Currently xol_add_vma() uses get_unmapped_area() for area->vaddr, but the next patches need to use the fixed address. So this patch adds the new "vaddr" argument to __create_xol_area() which should be used as area->vaddr if it is nonzero. xol_add_vma() doesn't bother to verify that the predefined addr is not used, insert_vm_struct() should fail if find_vma_links() detects the overlap with the existing vma. Also, __create_xol_area() doesn't need __GFP_ZERO to allocate area. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29uprobes: Introduce __create_xol_area()Oleg Nesterov1-22/+25
No functional changes, preparation. Extract the code which actually allocates/installs the new area into the new helper, __create_xol_area(). While at it remove the unnecessary "ret = ENOMEM" and "ret = 0" in xol_add_vma(), they both have no effect. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29uprobes: Change the callsite of uprobe_copy_process()Oleg Nesterov2-9/+9
Preparation for the next patches. Move the callsite of uprobe_copy_process() in copy_process() down to the succesfull return. We do not care if copy_process() fails, uprobe_free_utask() won't be called in this case so the wrong ->utask != NULL doesn't matter. OTOH, with this change we know that copy_process() can't fail when uprobe_copy_process() is called, the new task should either return to user-mode or call do_exit(). This way uprobe_copy_process() can: 1. setup p->utask != NULL if necessary 2. setup uprobes_state.xol_area 3. use task_work_add(p) Also, move the definition of uprobe_copy_process() down so that it can see get_utask(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29uprobes: Remove the wrong __weak attributeRalf Baechle1-1/+1
linux/uprobes.h declares arch_uprobe_skip_sstep() as a weak function. But as there is no definition of generic version so when trying to build uprobes for an architecture that doesn't yet have a arch_uprobe_skip_sstep() implementation, the vmlinux will try to call arch_uprobe_skip_sstep() somehwere in Stupidhistan leading to a system crash. We rather want a proper link error so remove arch_uprobe_skip_sstep(). Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-10-29Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds22-81/+176
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 Torvalds1-1/+1
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>
2013-10-29perf: Fix the perf context switch optimizationPeter Zijlstra1-18/+46
Currently we only optimize the context switch between two contexts that have the same parent; this forgoes the optimization between parent and child context, even though these contexts could be equivalent too. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Shishkin, Alexander <alexander.shishkin@intel.com> Link: http://lkml.kernel.org/r/20131007164257.GH3081@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29drm/i915: Fix the PPT fdi lane bifurcate state handling on ivbDaniel Vetter1-47/+48
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>
2013-10-29perf/x86: Further optimize copy_from_user_nmi()Peter Zijlstra2-48/+36
Now that we can deal with nested NMI due to IRET re-enabling NMIs and can deal with faults from NMI by making sure we preserve CR2 over NMIs we can in fact simply access user-space memory from NMI context. So rewrite copy_from_user_nmi() to use __copy_from_user_inatomic() and rework the fault path to do the minimal required work before taking the in_atomic() fault handler. In particular avoid perf_sw_event() which would make perf recurse on itself (it should be harmless as our recursion protections should be able to deal with this -- but why tempt fate). Also rename notify_page_fault() to kprobes_fault() as that is a much better name; there is no notifier in it and its specific to kprobes. Don measured that his worst case NMI path shrunk from ~300K cycles to ~150K cycles. Cc: Stephane Eranian <eranian@google.com> Cc: jmario@redhat.com Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: dave.hansen@linux.intel.com Tested-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131024105206.GM2490@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf: Change zero-padding of strings in perf_event_mmap_event()Peter Zijlstra1-6/+11
Oleg complained about the excessive 0-ing in perf_event_mmap_event(), so try and be smarter about it while keeping it fairly fool proof and avoid leaking random bits out to userspace. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-8jirlm99m6if2z13wd6rbyu6@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf: Do not waste PAGE_SIZE bytes for ALIGN(8) in perf_event_mmap_event()Oleg Nesterov1-7/+8
perf_event_mmap_event() does kzalloc(PATH_MAX + sizeof(u64)) to ensure we can align the size later. However this means that we actually allocate PAGE_SIZE * 2 buffer, seems too much. Change this code to allocate PATH_MAX==PAGE_SIZE bytes, but tell d_path() to not use the last sizeof(u64) bytes. Note: it is not clear why do we need __GFP_ZERO, see the next patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131016201004.GC23214@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf: Kill the dead !vma->vm_mm code in perf_event_mmap_event()Oleg Nesterov1-8/+6
1. perf_event_mmap(vma) is never called with a gate_vma-like arg, remove the "if (!vma->vm_mm)" code. 2. arch_vma_name() can use the chached value of mmap_event->vma. 3. Change the code to not call arch_vma_name() twice. 4. Purely cosmetic, but since we use "goto got_name" all the time remove "else" from "[stack]" branch just for symmetry. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131016200945.GB23214@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf: Remove useless atomic_tPeter Zijlstra1-9/+9
There's nothing atomic about atomic_set vs atomic_read; so remove the atomic_t usage. Also, make running_sample_length static as it really is (and should be) local to this translation unit. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: eranian@google.com Cc: Don Zickus <dzickus@redhat.com> Cc: jmario@redhat.com Cc: acme@infradead.org Cc: dave.hansen@linux.intel.com Link: http://lkml.kernel.org/n/tip-vw9lg588x1ic248whybjon0c@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29perf/x86: Fix NMI measurementsPeter Zijlstra2-5/+5
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 Zijlstra2-9/+34
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 Gorman1-1/+1
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 Gorman2-26/+26
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 Gorman2-44/+34
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 Gorman1-14/+30
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 Gorman1-7/+16
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>
2013-10-29mm: numa: Do not account for a hinting fault if we racedMel Gorman1-1/+4
If another task handled a hinting fault in parallel then do not double account for it. 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/1381141781-10992-5-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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