- 09 Jun, 2014 3 commits
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Michael S. Tsirkin authored
Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Michael S. Tsirkin authored
All memory accesses are done under some VQ mutex. So lock/unlock all VQs is a faster equivalent of synchronize_rcu() for memory access changes. Some guests cause a lot of these changes, so it's helpful to make them faster. Reported-by: "Gonglei (Arei)" <arei.gonglei@huawei.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Michael S. Tsirkin authored
Michael Mueller provided a patch to reduce the size of vhost-net structure as some allocations could fail under memory pressure/fragmentation. We are still left with high order allocations though. This patch is handling the problem at the core level, allowing vhost structures to use vmalloc() if kmalloc() failed. As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT to kzalloc() flags to do this fallback only when really needed. People are still looking at cleaner ways to handle the problem at the API level, probably passing in multiple iovecs. This hack seems consistent with approaches taken since then by drivers/vhost/scsi.c and net/core/dev.c Based on patch by Romain Francoise. Cc: Michael Mueller <mimu@linux.vnet.ibm.com> Signed-off-by: Romain Francoise <romain@orebokech.com> Acked-by: Michael S. Tsirkin <mst@redhat.com>
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- 08 Jun, 2014 2 commits
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Linus Torvalds authored
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Linus Torvalds authored
This reverts commit 3e1a878b. It came in very late, and already has one reported failure: Sitsofe reports that the current tree fails to boot on his EeePC, and bisected it down to this. Rather than waste time trying to figure out what's wrong, just revert it. Reported-by: Sitsofe Wheeler <sitsofe@gmail.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- 07 Jun, 2014 4 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds authored
Pull btrfs fix from Chris Mason: "I had this in my 3.16 merge window queue, but it is small and obvious enough for 3.15. I cherry-picked and retested against current rc8" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: send, fix corrupted path strings for long paths
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git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pendingLinus Torvalds authored
Pull SCSI target fixes from Nicholas Bellinger: "Here are the remaining fixes for v3.15. This series includes: - iser-target fix for ImmediateData exception reference count bug (Sagi + nab) - iscsi-target fix for MC/S login + potential iser-target MRDSL buffer overrun (Santosh + Roland) - iser-target fix for v3.15-rc multi network portal shutdown regression (nab) - target fix for allowing READ_CAPCITY during ALUA Standby access state (Chris + nab) - target fix for NULL pointer dereference of alua_access_state for un-configured devices (Chris + nab)" * git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: target: Fix alua_access_state attribute OOPs for un-configured devices target: Allow READ_CAPACITY opcode in ALUA Standby access state iser-target: Fix multi network portal shutdown regression iscsi-target: Fix wrong buffer / buffer overrun in iscsi_change_param_value() iser-target: Add missing target_put_sess_cmd for ImmedateData failure
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Peter Anvin: "A significantly larger than I'd like set of patches for just below the wire. All of these, however, fix real problems. The one thing that is genuinely scary in here is the change of SMP initialization, but that *does* fix a confirmed hang when booting virtual machines. There is also a patch to actually do the right thing about not offlining a CPU when there are not enough interrupt vectors available in the system; the accounting was done incorrectly. The worst case for that patch is that we fail to offline CPUs when we should (the new code is strictly more conservative than the old), so is not particularly risky. Most of the rest is minor stuff; the EFI patches are all about exporting correct information to boot loaders and kexec" * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: EFI_MIXED should not prohibit loading above 4G x86/smpboot: Initialize secondary CPU only if master CPU will wait for it x86/smpboot: Log error on secondary CPU wakeup failure at ERR level x86: Fix list/memory corruption on CPU hotplug x86: irq: Get correct available vectors for cpu disable x86/efi: Do not export efi runtime map in case old map x86/efi: earlyprintk=efi,keep fix
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Matt Fleming authored
commit 7d453eee ("x86/efi: Wire up CONFIG_EFI_MIXED") introduced a regression for the functionality to load kernels above 4G. The relevant (incorrect) reasoning behind this change can be seen in the commit message, "The xloadflags field in the bzImage header is also updated to reflect that the kernel supports both entry points by setting both of XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y. XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is guaranteed to be addressable with 32-bits." This is obviously bogus since 32-bit EFI loaders will never place the kernel above the 4G mark. So this restriction is entirely unnecessary. But things are worse than that - since we want to encourage people to always compile with CONFIG_EFI_MIXED=y so that their kernels work out of the box for both 32-bit and 64-bit firmware, commit 7d453eee effectively disables XLF_CAN_BE_LOADED_ABOVE_4G completely. Remove the overzealous and superfluous restriction and restore the XLF_CAN_BE_LOADED_ABOVE_4G functionality. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1402140380-15377-1-git-send-email-matt@console-pimps.orgSigned-off-by: H. Peter Anvin <hpa@zytor.com>
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- 06 Jun, 2014 6 commits
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Naoya Horiguchi authored
The age table walker doesn't check non-present hugetlb entry in common path, so hugetlb_entry() callbacks must check it. The reason for this behavior is that some callers want to handle it in its own way. [ I think that reason is bogus, btw - it should just do what the regular code does, which is to call the "pte_hole()" function for such hugetlb entries - Linus] However, some callers don't check it now, which causes unpredictable result, for example when we have a race between migrating hugepage and reading /proc/pid/numa_maps. This patch fixes it by adding !pte_present checks on buggy callbacks. This bug exists for years and got visible by introducing hugepage migration. ChangeLog v2: - fix if condition (check !pte_present() instead of pte_present()) Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Backported to 3.15. Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org> ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Filipe Manana authored
If a path has more than 230 characters, we allocate a new buffer to use for the path, but we were forgotting to copy the contents of the previous buffer into the new one, which has random content from the kmalloc call. Test: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt TEST_PATH="/mnt/fdmanana/.config/google-chrome-mysetup/Default/Pepper_Data/Shockwave_Flash/WritableRoot/#SharedObjects/JSHJ4ZKN/s.wsj.net/[[IMPORT]]/players.edgesuite.net/flash/plugins/osmf/advanced-streaming-plugin/v2.7/osmf1.6/Ak#" mkdir -p $TEST_PATH echo "hello world" > $TEST_PATH/amaiAdvancedStreamingPlugin.txt btrfs subvolume snapshot -r /mnt /mnt/mysnap1 btrfs send /mnt/mysnap1 -f /tmp/1.snap A test for xfstests follows. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Cc: Marc Merlin <marc@merlins.org> Tested-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Chris Mason <clm@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fixes from Ingo Molnar: "Four misc fixes: each was deemed serious enough to warrant v3.15 inclusion" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix tg_set_cfs_bandwidth() deadlock on rq->lock sched/dl: Fix race in dl_task_timer() sched: Fix sched_policy < 0 comparison sched/numa: Fix use of spin_{un}lock_irq() when interrupts are disabled
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Andrey Ryabinin authored
While working address sanitizer for kernel I've discovered use-after-free bug in __put_anon_vma. For the last anon_vma, anon_vma->root freed before child anon_vma. Later in anon_vma_free(anon_vma) we are referencing to already freed anon_vma->root to check rwsem. This fixes it by freeing the child anon_vma before freeing anon_vma->root. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> # v3.0+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nicholas Bellinger authored
This patch fixes a OOPs where an attempt to write to the per-device alua_access_state configfs attribute at: /sys/kernel/config/target/core/$HBA/$DEV/alua/$TG_PT_GP/alua_access_state results in an NULL pointer dereference when the backend device has not yet been configured. This patch adds an explicit check for DF_CONFIGURED, and fails with -ENODEV to avoid this case. Reported-by: Chris Boot <crb@tiger-computing.co.uk> Reported-by: Philip Gaw <pgaw@darktech.org.uk> Cc: Chris Boot <crb@tiger-computing.co.uk> Cc: Philip Gaw <pgaw@darktech.org.uk> Cc: stable@vger.kernel.org # 3.8+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Nicholas Bellinger authored
This patch allows READ_CAPACITY + SAI_READ_CAPACITY_16 opcode processing to occur while the associated ALUA group is in Standby access state. This is required to avoid host side LUN probe failures during the initial scan if an ALUA group has already implicitly changed into Standby access state. This addresses a bug reported by Chris + Philip using dm-multipath + ESX hosts configured with ALUA multipath. Reported-by: Chris Boot <crb@tiger-computing.co.uk> Reported-by: Philip Gaw <pgaw@darktech.org.uk> Cc: Chris Boot <crb@tiger-computing.co.uk> Cc: Philip Gaw <pgaw@darktech.org.uk> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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- 05 Jun, 2014 15 commits
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H. Peter Anvin authored
* Fix earlyprintk=efi,keep support by switching to an ioremap() mapping of the framebuffer when early_ioremap() is no longer available and dropping __init from functions that may be invoked after free_initmem() - Dave Young * We shouldn't be exporting the EFI runtime map in sysfs if not using the new 1:1 EFI mapping code since in that case the mappings are not static across a kexec reboot - Dave Young Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Ingo Molnar: "Two last minute tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf probe: Fix perf probe to find correct variable DIE perf probe: Fix a segfault if asked for variable it doesn't find
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Linus Torvalds authored
Merge futex fixes from Thomas Gleixner: "So with more awake and less futex wreckaged brain, I went through my list of points again and came up with the following 4 patches. 1) Prevent pi requeueing on the same futex I kept Kees check for uaddr1 == uaddr2 as a early check for private futexes and added a key comparison to both futex_requeue and futex_wait_requeue_pi. Sebastian, sorry for the confusion yesterday night. I really misunderstood your question. You are right the check is pointless for shared futexes where the same physical address is mapped to two different virtual addresses. 2) Sanity check atomic acquisiton in futex_lock_pi_atomic That's basically what Darren suggested. I just simplified it to use futex_top_waiter() to find kernel internal state. If state is found return -EINVAL and do not bother to fix up the user space variable. It's corrupted already. 3) Ensure state consistency in futex_unlock_pi The code is silly versus the owner died bit. There is no point to preserve it on unlock when the user space thread owns the futex. What's worse is that it does not update the user space value when the owner died bit is set. So the kernel itself creates observable inconsistency. Another "optimization" is to retry an atomic unlock. That's pointless as in a sane environment user space would not call into that code if it could have unlocked it atomically. So we always check whether there is kernel state around and only if there is none, we do the unlock by setting the user space value to 0. 4) Sanitize lookup_pi_state lookup_pi_state is ambigous about TID == 0 in the user space value. This can be a valid state even if there is kernel state on this uaddr, but we miss a few corner case checks. I tried to come up with a smaller solution hacking the checks into the current cruft, but it turned out to be ugly as hell and I got more confused than I was before. So I rewrote the sanity checks along the state documentation with awful lots of commentry" * emailed patches from Thomas Gleixner <tglx@linutronix.de>: futex: Make lookup_pi_state more robust futex: Always cleanup owner tid in unlock_pi futex: Validate atomic acquisition in futex_lock_pi_atomic() futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1)
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Thomas Gleixner authored
The current implementation of lookup_pi_state has ambigous handling of the TID value 0 in the user space futex. We can get into the kernel even if the TID value is 0, because either there is a stale waiters bit or the owner died bit is set or we are called from the requeue_pi path or from user space just for fun. The current code avoids an explicit sanity check for pid = 0 in case that kernel internal state (waiters) are found for the user space address. This can lead to state leakage and worse under some circumstances. Handle the cases explicit: Waiter | pi_state | pi->owner | uTID | uODIED | ? [1] NULL | --- | --- | 0 | 0/1 | Valid [2] NULL | --- | --- | >0 | 0/1 | Valid [3] Found | NULL | -- | Any | 0/1 | Invalid [4] Found | Found | NULL | 0 | 1 | Valid [5] Found | Found | NULL | >0 | 1 | Invalid [6] Found | Found | task | 0 | 1 | Valid [7] Found | Found | NULL | Any | 0 | Invalid [8] Found | Found | task | ==taskTID | 0/1 | Valid [9] Found | Found | task | 0 | 0 | Invalid [10] Found | Found | task | !=taskTID | 0/1 | Invalid [1] Indicates that the kernel can acquire the futex atomically. We came came here due to a stale FUTEX_WAITERS/FUTEX_OWNER_DIED bit. [2] Valid, if TID does not belong to a kernel thread. If no matching thread is found then it indicates that the owner TID has died. [3] Invalid. The waiter is queued on a non PI futex [4] Valid state after exit_robust_list(), which sets the user space value to FUTEX_WAITERS | FUTEX_OWNER_DIED. [5] The user space value got manipulated between exit_robust_list() and exit_pi_state_list() [6] Valid state after exit_pi_state_list() which sets the new owner in the pi_state but cannot access the user space value. [7] pi_state->owner can only be NULL when the OWNER_DIED bit is set. [8] Owner and user space value match [9] There is no transient state which sets the user space TID to 0 except exit_robust_list(), but this is indicated by the FUTEX_OWNER_DIED bit. See [4] [10] There is no transient state which leaves owner and user space TID out of sync. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Cc: Darren Hart <dvhart@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Thomas Gleixner authored
If the owner died bit is set at futex_unlock_pi, we currently do not cleanup the user space futex. So the owner TID of the current owner (the unlocker) persists. That's observable inconsistant state, especially when the ownership of the pi state got transferred. Clean it up unconditionally. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Cc: Darren Hart <dvhart@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Thomas Gleixner authored
We need to protect the atomic acquisition in the kernel against rogue user space which sets the user space futex to 0, so the kernel side acquisition succeeds while there is existing state in the kernel associated to the real owner. Verify whether the futex has waiters associated with kernel state. If it has, return -EINVAL. The state is corrupted already, so no point in cleaning it up. Subsequent calls will fail as well. Not our problem. [ tglx: Use futex_top_waiter() and explain why we do not need to try restoring the already corrupted user space state. ] Signed-off-by: Darren Hart <dvhart@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Will Drewry <wad@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Thomas Gleixner authored
futex-prevent-requeue-pi-on-same-futex.patch futex: Forbid uaddr == uaddr2 in futex_requeue(..., requeue_pi=1) If uaddr == uaddr2, then we have broken the rule of only requeueing from a non-pi futex to a pi futex with this call. If we attempt this, then dangling pointers may be left for rt_waiter resulting in an exploitable condition. This change brings futex_requeue() in line with futex_wait_requeue_pi() which performs the same check as per commit 6f7b0a2a ("futex: Forbid uaddr == uaddr2 in futex_wait_requeue_pi()") [ tglx: Compare the resulting keys as well, as uaddrs might be different depending on the mapping ] Fixes CVE-2014-3153. Reported-by: Pinkie Pie Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Igor Mammedov authored
Hang is observed on virtual machines during CPU hotplug, especially in big guests with many CPUs. (It reproducible more often if host is over-committed). It happens because master CPU gives up waiting on secondary CPU and allows it to run wild. As result AP causes locking or crashing system. For example as described here: https://lkml.org/lkml/2014/3/6/257 If master CPU have sent STARTUP IPI successfully, and AP signalled to master CPU that it's ready to start initialization, make master CPU wait indefinitely till AP is onlined. To ensure that AP won't ever run wild, make it wait at early startup till master CPU confirms its intention to wait for AP. If AP doesn't respond in 10 seconds, the master CPU will timeout and cancel AP onlining. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1401975765-22328-4-git-send-email-imammedo@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Igor Mammedov authored
If system is running without debug level logging, it will not log error if do_boot_cpu() failed to wakeup AP. It may lead to silent AP bringup failures at boot time. Change message level to KERN_ERR to make error visible to user as it's done on other architectures. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1401975765-22328-3-git-send-email-imammedo@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Igor Mammedov authored
currently if AP wake up is failed, master CPU marks AP as not present in do_boot_cpu() by calling set_cpu_present(cpu, false). That leads to following list corruption on the next physical CPU hotplug: [ 418.107336] WARNING: CPU: 1 PID: 45 at lib/list_debug.c:33 __list_add+0xbe/0xd0() [ 418.115268] list_add corruption. prev->next should be next (ffff88003dc57600), but was ffff88003e20c3a0. (prev=ffff88003e20c3a0). [ 418.123693] Modules linked in: nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT ipt_REJECT cfg80211 xt_conntrack rfkill ee [ 418.138979] CPU: 1 PID: 45 Comm: kworker/u10:1 Not tainted 3.14.0-rc6+ #387 [ 418.149989] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 [ 418.165750] Workqueue: kacpi_hotplug acpi_hotplug_work_fn [ 418.166433] 0000000000000021 ffff880038ca7988 ffffffff8159b22d 0000000000000021 [ 418.176460] ffff880038ca79d8 ffff880038ca79c8 ffffffff8106942c ffff880038ca79e8 [ 418.177453] ffff88003e20c3a0 ffff88003dc57600 ffff88003e20c3a0 00000000ffffffea [ 418.178445] Call Trace: [ 418.185811] [<ffffffff8159b22d>] dump_stack+0x49/0x5c [ 418.186440] [<ffffffff8106942c>] warn_slowpath_common+0x8c/0xc0 [ 418.187192] [<ffffffff81069516>] warn_slowpath_fmt+0x46/0x50 [ 418.191231] [<ffffffff8136ef51>] ? acpi_ns_get_node+0xb7/0xc7 [ 418.193889] [<ffffffff812f796e>] __list_add+0xbe/0xd0 [ 418.196649] [<ffffffff812e2aa9>] kobject_add_internal+0x79/0x200 [ 418.208610] [<ffffffff812e2e18>] kobject_add_varg+0x38/0x60 [ 418.213831] [<ffffffff812e2ef4>] kobject_add+0x44/0x70 [ 418.229961] [<ffffffff813e2c60>] device_add+0xd0/0x550 [ 418.234991] [<ffffffff813f0e95>] ? pm_runtime_init+0xe5/0xf0 [ 418.250226] [<ffffffff813e32be>] device_register+0x1e/0x30 [ 418.255296] [<ffffffff813e82a3>] register_cpu+0xe3/0x130 [ 418.266539] [<ffffffff81592be5>] arch_register_cpu+0x65/0x150 [ 418.285845] [<ffffffff81355c0d>] acpi_processor_hotadd_init+0x5a/0x9b ... Which is caused by the fact that generic_processor_info() allocates logical CPU id by calling: cpu = cpumask_next_zero(-1, cpu_present_mask); which returns id of previously failed to wake up CPU, since its bit is cleared by do_boot_cpu() and as result register_cpu() tries to register another CPU with the same id as already present but failed to be onlined CPU. Taking in account that AP will not do anything if master CPU failed to wake it up, there is no reason to mark that AP as not present and break next cpu hotplug attempts. As a side effect of not marking AP as not present, user would be allowed to online it again later. Also fix memory corruption in acpi_unmap_lsapic() if during CPU hotplug master CPU failed to wake up AP it set percpu x86_cpu_to_apicid to BAD_APICID=0xFFFF for AP. However following attempt to unplug that CPU will lead to out of bound write access to __apicid_to_node[] which is 32768 items long on x86_64 kernel. So with above fix of cpu_present_mask make sure that a present CPU has a valid APIC ID by not setting x86_cpu_to_apicid to BAD_APICID in do_boot_cpu() on failure and allow acpi_processor_remove()->acpi_unmap_lsapic() cleanly remove CPU. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1401975765-22328-2-git-send-email-imammedo@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Roman Gushchin authored
tg_set_cfs_bandwidth() sets cfs_b->timer_active to 0 to force the period timer restart. It's not safe, because can lead to deadlock, described in commit 927b54fc: "__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." Three CPUs must be involved: CPU0 CPU1 CPU2 take rq->lock period timer fired ... take cfs_b lock ... ... tg_set_cfs_bandwidth() throttle_cfs_rq() release cfs_b lock take cfs_b lock ... distribute_cfs_runtime() timer_active = 0 take cfs_b->lock wait for rq->lock ... __start_cfs_bandwidth() {wait for timer callback break if timer_active == 1} So, CPU0 and CPU1 are deadlocked. Instead of resetting cfs_b->timer_active, tg_set_cfs_bandwidth can wait for period timer callbacks (ignoring cfs_b->timer_active) and restart the timer explicitly. Signed-off-by: Roman Gushchin <klamm@yandex-team.ru> Reviewed-by: Ben Segall <bsegall@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/87wqdi9g8e.wl\%klamm@yandex-team.ru Cc: pjt@google.com Cc: chris.j.arges@canonical.com Cc: gregkh@linuxfoundation.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kirill Tkhai authored
Throttled task is still on rq, and it may be moved to other cpu if user is playing with sched_setaffinity(). Therefore, unlocked task_rq() access makes the race. Juri Lelli reports he got this race when dl_bandwidth_enabled() was not set. Other thing, pointed by Peter Zijlstra: "Now I suppose the problem can still actually happen when you change the root domain and trigger a effective affinity change that way". To fix that we do the same as made in __task_rq_lock(). We do not use __task_rq_lock() itself, because it has a useful lockdep check, which is not correct in case of dl_task_timer(). We do not need pi_lock locked here. This case is an exception (PeterZ): "The only reason we don't strictly need ->pi_lock now is because we're guaranteed to have p->state == TASK_RUNNING here and are thus free of ttwu races". Signed-off-by: Kirill Tkhai <tkhai@yandex.ru> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> # v3.14+ Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/3056991400578422@web14g.yandex.ruSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Richard Weinberger authored
attr.sched_policy is u32, therefore a comparison against < 0 is never true. Fix this by casting sched_policy to int. This issue was reported by coverity CID 1219934. Fixes: dbdb2275 ("sched: Disallow sched_attr::sched_policy < 0") Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1401741514-7045-1-git-send-email-richard@nod.atSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Steven Rostedt authored
As Peter Zijlstra told me, we have the following path: do_exit() exit_itimers() itimer_delete() spin_lock_irqsave(&timer->it_lock, &flags); timer_delete_hook(timer); kc->timer_del(timer) := posix_cpu_timer_del() put_task_struct() __put_task_struct() task_numa_free() spin_lock(&grp->lock); Which means that task_numa_free() can be called with interrupts disabled, which means that we should not be using spin_lock_irq() but spin_lock_irqsave() instead. Otherwise we are enabling interrupts while holding an interrupt unsafe lock! Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner<tglx@linutronix.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140527182541.GH11096@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/urgent Pull perf/urgent fixes from Jiri Olsa: * Fix perf probe to find correct variable DIE (Masami Hiramatsu) * Fix a segfault in perf probe if asked for variable it doesn't find (Masami Hiramatsu) Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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- 04 Jun, 2014 10 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpuLinus Torvalds authored
Pull percpu fix from Tejun Heo: "It is very late but this is an important percpu-refcount fix from Sebastian Ott. The problem is that percpu_ref_*() used __this_cpu_*() instead of this_cpu_*(). The difference between the two is that the latter is atomic on the local cpu while the former is not. this_cpu_inc() is guaranteed to increment the percpu counter on the cpu that the operation is executed on without any synchronization; however, __this_cpu_inc() doesn't and if the local cpu invokes the function from different contexts (e.g. process and irq) of the same CPU, it's not guaranteed to actually increment as it may be implemented as rmw. This bug existed from the get-go but it hasn't been noticed earlier probably because on x86 __this_cpu_inc() is equivalent to this_cpu_inc() as both get translated into single instruction; however, s390 uses the generic rmw implementation and gets affected by the bug. Kudos to Sebastian and Heiko for diagnosing it. The change is very low risk and fixes a critical issue on the affected architectures, so I think it's a good candidate for inclusion although it's very late in the devel cycle. On the other hand, this has been broken since v3.11, so backporting it through -stable post -rc1 won't be the end of the world. I'll ping Christoph whether __this_cpu_*() ops can be better annotated so that it can trigger lockdep warning when used from multiple contexts" * 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu-refcount: fix usage of this_cpu_ops
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Sebastian Ott authored
The percpu-refcount infrastructure uses the underscore variants of this_cpu_ops in order to modify percpu reference counters. (e.g. __this_cpu_inc()). However the underscore variants do not atomically update the percpu variable, instead they may be implemented using read-modify-write semantics (more than one instruction). Therefore it is only safe to use the underscore variant if the context is always the same (process, softirq, or hardirq). Otherwise it is possible to lose updates. This problem is something that Sebastian has seen within the aio subsystem which uses percpu refcounters both in process and softirq context leading to reference counts that never dropped to zeroes; even though the number of "get" and "put" calls matched. Fix this by using the non-underscore this_cpu_ops variant which provides correct per cpu atomic semantics and fixes the corrupted reference counts. Cc: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> # v3.11+ Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org> References: http://lkml.kernel.org/g/alpine.LFD.2.11.1406041540520.21183@denkbrett
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull intel pstate fixes from Rafael Wysocki: "Final power management fixes for 3.15 - Taking non-idle time into account when calculating core busy time was a mistake and led to a performance regression. Since the problem it was supposed to address is now taken care of in a different way, we don't need to do it any more, so drop the non-idle time tracking from intel_pstate. Dirk Brandewie. - Changing to fixed point math throughout the busy calculation introduced rounding errors that adversely affect the accuracy of intel_pstate's computations. Fix from Dirk Brandewie. - The PID controller algorithm used by intel_pstate assumes that the time interval between two adjacent samples will always be the same which is not the case for deferable timers (used by intel_pstate) when the system is idle. This leads to inaccurate predictions and artificially increases convergence times for the minimum P-state. Fix from Dirk Brandewie. - intel_pstate carries out computations using 32-bit variables that may overflow for large enough values of APERF/MPERF. Switch to using 64-bit variables for computations, from Doug Smythies" * tag 'pm-3.15-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: intel_pstate: Improve initial busy calculation intel_pstate: add sample time scaling intel_pstate: Correct rounding in busy calculation intel_pstate: Remove C0 tracking
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git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
Pull drm fixes from Dave Airlie: "All fairly small: radeon stability and a panic path fix. Mostly radeon fixes, suspend/resume fix, stability on the CIK chipsets, along with a locking check avoidance patch for panic times regression" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/radeon: use the CP DMA on CIK drm/radeon: sync page table updates drm/radeon: fix vm buffer size estimation drm/crtc-helper: skip locking checks in panicking path drm/radeon/dpm: resume fixes for some systems
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Masami Hiramatsu authored
Fix perf probe to find correct variable DIE which has location or external instance by tracking down the lexical blocks. Current die_find_variable() expects that the all variable DIEs which has DW_TAG_variable have a location. However, since recent dwarf information may have declaration variable DIEs at the entry of function (subprogram), die_find_variable() returns it. To solve this problem, it must track down the DIE tree to find a DIE which has an actual location or a reference for external instance. e.g. finding a DIE which origin is <0xdc73>; <1><11496>: Abbrev Number: 95 (DW_TAG_subprogram) <11497> DW_AT_abstract_origin: <0xdc42> <1149b> DW_AT_low_pc : 0x1850 [...] <2><114cc>: Abbrev Number: 119 (DW_TAG_variable) <- this is a declaration <114cd> DW_AT_abstract_origin: <0xdc73> <2><114d1>: Abbrev Number: 119 (DW_TAG_variable) [...] <3><115a7>: Abbrev Number: 105 (DW_TAG_lexical_block) <115a8> DW_AT_ranges : 0xaa0 <4><115ac>: Abbrev Number: 96 (DW_TAG_variable) <- this has a location <115ad> DW_AT_abstract_origin: <0xdc73> <115b1> DW_AT_location : 0x486c (location list) Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20140529121930.30879.87092.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: Jiri Olsa <jolsa@kernel.org>
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Masami Hiramatsu authored
Fix a segfault bug by asking for variable it doesn't find. Since the convert_variable() didn't handle error code returned from convert_variable_location(), it just passed an incomplete variable field and then a segfault was occurred when formatting the field. This fixes that bug by handling success code correctly in convert_variable(). Other callers of convert_variable_location() are correctly checking the return code. This bug was introduced by following commit. But another hidden erroneous error handling has been there previously (-ENOMEM case). commit 3d918a12Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20140529105232.28251.30447.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: Jiri Olsa <jolsa@kernel.org>
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Yinghai Lu authored
check_irq_vectors_for_cpu_disable() can overestimate the number of available interrupt vectors, so the check for cpu down succeeds, but the actual cpu removal fails. It iterates from FIRST_EXTERNAL_VECTOR to NR_VECTORS, which is wrong because the systems vectors are not taken into account. Limit the search to first_system_vector instead of NR_VECTORS. The second indicator for vector availability the used_vectors bitmap is not taken into account at all. So system vectors, e.g. IA32_SYSCALL_VECTOR (0x80) and IRQ_MOVE_CLEANUP_VECTOR (0x20), are accounted as available. Add a check for the used_vectors bitmap and do not account vectors which are marked there. [ tglx: Simplified code. Rewrote changelog and code comments. ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Prarit Bhargava <prarit@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Elliott, Robert (Server Storage)" <Elliott@hp.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1400160305-17774-2-git-send-email-prarit@redhat.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
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git://people.freedesktop.org/~deathsimple/linuxDave Airlie authored
The first one is a one liner fixing a stupid typo in the VM handling code and is only relevant if play with one of the VM defines. The other two switches CIK to use the CPDMA instead of the SDMA for buffer moves, as it turned out the SDMA is still sometimes not 100% reliable. * 'drm-fixes-3.15' of git://people.freedesktop.org/~deathsimple/linux: drm/radeon: use the CP DMA on CIK drm/radeon: sync page table updates drm/radeon: fix vm buffer size estimation
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Nicholas Bellinger authored
This patch fixes a iser-target specific regression introduced in v3.15-rc6 with: commit 14f4b54f Author: Sagi Grimberg <sagig@mellanox.com> Date: Tue Apr 29 13:13:47 2014 +0300 Target/iscsi,iser: Avoid accepting transport connections during stop stage where the change to set iscsi_np->enabled = false within iscsit_clear_tpg_np_login_thread() meant that a iscsi_np with two iscsi_tpg_np exports would have it's parent iscsi_np set to a disabled state, even if other iscsi_tpg_np exports still existed. This patch changes iscsit_clear_tpg_np_login_thread() to only set iscsi_np->enabled = false when shutdown = true, and also changes iscsit_del_np() to set iscsi_np->enabled = true when iscsi_np->np_exports is non zero. Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Roland Dreier authored
In non-leading connection login, iscsi_login_non_zero_tsih_s1() calls iscsi_change_param_value() with the buffer it uses to hold the login PDU, not a temporary buffer. This leads to the login header getting corrupted and login failing for non-leading connections in MC/S. Fix this by adding a wrapper iscsi_change_param_sprintf() that handles the temporary buffer itself to avoid confusion. Also handle sending a reject in case of failure in the wrapper, which lets the calling code get quite a bit smaller and easier to read. Finally, bump the size of the temporary buffer from 32 to 64 bytes to be safe, since "MaxRecvDataSegmentLength=" by itself is 25 bytes; with a trailing NUL, a value >= 1M will lead to a buffer overrun. (This isn't the default but we don't need to run right at the ragged edge here) Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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