- 07 Aug, 2015 24 commits
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Linus Torvalds authored
Merge fixes from Andrew Morton: "21 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits) writeback: fix initial dirty limit mm/memory-failure: set PageHWPoison before migrate_pages() mm: check __PG_HWPOISON separately from PAGE_FLAGS_CHECK_AT_* mm/memory-failure: give up error handling for non-tail-refcounted thp mm/memory-failure: fix race in counting num_poisoned_pages mm/memory-failure: unlock_page before put_page ipc: use private shmem or hugetlbfs inodes for shm segments. mm: initialize hotplugged pages as reserved ocfs2: fix shift left overflow kthread: export kthread functions fsnotify: fix oops in fsnotify_clear_marks_by_group_flags() lib/iommu-common.c: do not use 0xffffffffffffffffl for computing align_mask mm/slub: allow merging when SLAB_DEBUG_FREE is set signalfd: fix information leak in signalfd_copyinfo signal: fix information leak in copy_siginfo_to_user signal: fix information leak in copy_siginfo_from_user32 ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() fs, file table: reinit files_stat.max_files after deferred memory initialisation mm, meminit: replace rwsem with completion mm, meminit: allow early_pfn_to_nid to be used during runtime ...
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git://people.freedesktop.org/~agd5f/linuxLinus Torvalds authored
Pull amdgpu fixes from Alex Deucher: "Just a few amdgpu fixes to make sure we report the proper firmware information and number of render buffers to userspace and a typo in a debugging function" [ Pulling directly from Alex since Dave Airlie is on vacation - Linus ] * 'drm-fixes-4.2' of git://people.freedesktop.org/~agd5f/linux: drm/amdgpu: set fw_version and feature_version for smu fw loading drm/amdgpu: add feature version for SDMA ucode drm/amdgpu: add feature version for RLC and MEC v2 drm/amdgpu: increment queue when iterating on this variable. drm/amdgpu: fix rb setting for CZ
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git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds authored
Pull TDA998x i2c driver fixes from Russell King: "This fixes the double-checksumming of the AVI infoframe which was resulting in the checksum always being zero. It went unnoticed as none of my HDMI devices had a problem with this" [ Pulling directly from rmk since Dave Airlie is on vacation - Linus ] * 'drm-tda998x-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: drm/i2c: tda998x: fix bad checksum of the HDMI AVI infoframe
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Rabin Vincent authored
The initial value of global_wb_domain.dirty_limit set by writeback_set_ratelimit() is zeroed out by the memset in wb_domain_init(). Signed-off-by:
Rabin Vincent <rabin.vincent@axis.com> Acked-by:
Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@fb.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Naoya Horiguchi authored
Now page freeing code doesn't consider PageHWPoison as a bad page, so by setting it before completing the page containment, we can prevent the error page from being reused just after successful page migration. I added TTU_IGNORE_HWPOISON for try_to_unmap() to make sure that the page table entry is transformed into migration entry, not to hwpoison entry. Signed-off-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dean Nelson <dnelson@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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Naoya Horiguchi authored
The race condition addressed in commit add05cec ("mm: soft-offline: don't free target page in successful page migration") was not closed completely, because that can happen not only for soft-offline, but also for hard-offline. Consider that a slab page is about to be freed into buddy pool, and then an uncorrected memory error hits the page just after entering __free_one_page(), then VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP) is triggered, despite the fact that it's not necessary because the data on the affected page is not consumed. To solve it, this patch drops __PG_HWPOISON from page flag checks at allocation/free time. I think it's justified because __PG_HWPOISON flags is defined to prevent the page from being reused, and setting it outside the page's alloc-free cycle is a designed behavior (not a bug.) For recent months, I was annoyed about BUG_ON when soft-offlined page remains on lru cache list for a while, which is avoided by calling put_page() instead of putback_lru_page() in page migration's success path. This means that this patch reverts a major change from commit add05cec about the new refcounting rule of soft-offlined pages, so "reuse window" revives. This will be closed by a subsequent patch. Signed-off-by:
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Naoya Horiguchi authored
"non anonymous thp" case is still racy with freeing thp, which causes panic due to put_page() for refcount-0 page. It seems that closing up this race might be hard (and/or not worth doing,) so let's give up the error handling for this case. Signed-off-by:
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Naoya Horiguchi authored
When memory_failure() is called on a page which are just freed after page migration from soft offlining, the counter num_poisoned_pages is raised twi= ce. So let's fix it with using TestSetPageHWPoison. Signed-off-by:
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Naoya Horiguchi authored
Recently I addressed a few of hwpoison race problems and the patches are merged on v4.2-rc1. It made progress, but unfortunately some problems still remain due to less coverage of my testing. So I'm trying to fix or avoid them in this series. One point I'm expecting to discuss is that patch 4/5 changes the page flag set to be checked on free time. In current behavior, __PG_HWPOISON is not supposed to be set when the page is freed. I think that there is no strong reason for this behavior, and it causes a problem hard to fix only in error handler side (because __PG_HWPOISON could be set at arbitrary timing.) So I suggest to change it. With this patchset, hwpoison stress testing in official mce-test testsuite (which previously failed) passes. This patch (of 5): In "just unpoisoned" path, we do put_page and then unlock_page, which is a wrong order and causes "freeing locked page" bug. So let's fix it. Signed-off-by:
David Rientjes <rientjes@google.com> Signed-off-by:
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Stephen Smalley authored
The shm implementation internally uses shmem or hugetlbfs inodes for shm segments. As these inodes are never directly exposed to userspace and only accessed through the shm operations which are already hooked by security modules, mark the inodes with the S_PRIVATE flag so that inode security initialization and permission checking is skipped. This was motivated by the following lockdep warning: ====================================================== [ INFO: possible circular locking dependency detected ] 4.2.0-0.rc3.git0.1.fc24.x86_64+debug #1 Tainted: G W ------------------------------------------------------- httpd/1597 is trying to acquire lock: (&ids->rwsem){+++++.}, at: shm_close+0x34/0x130 but task is already holding lock: (&mm->mmap_sem){++++++}, at: SyS_shmdt+0x4b/0x180 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: lock_acquire+0xc7/0x270 __might_fault+0x7a/0xa0 filldir+0x9e/0x130 xfs_dir2_block_getdents.isra.12+0x198/0x1c0 [xfs] xfs_readdir+0x1b4/0x330 [xfs] xfs_file_readdir+0x2b/0x30 [xfs] iterate_dir+0x97/0x130 SyS_getdents+0x91/0x120 entry_SYSCALL_64_fastpath+0x12/0x76 -> #2 (&xfs_dir_ilock_class){++++.+}: lock_acquire+0xc7/0x270 down_read_nested+0x57/0xa0 xfs_ilock+0x167/0x350 [xfs] xfs_ilock_attr_map_shared+0x38/0x50 [xfs] xfs_attr_get+0xbd/0x190 [xfs] xfs_xattr_get+0x3d/0x70 [xfs] generic_getxattr+0x4f/0x70 inode_doinit_with_dentry+0x162/0x670 sb_finish_set_opts+0xd9/0x230 selinux_set_mnt_opts+0x35c/0x660 superblock_doinit+0x77/0xf0 delayed_superblock_init+0x10/0x20 iterate_supers+0xb3/0x110 selinux_complete_init+0x2f/0x40 security_load_policy+0x103/0x600 sel_write_load+0xc1/0x750 __vfs_write+0x37/0x100 vfs_write+0xa9/0x1a0 SyS_write+0x58/0xd0 entry_SYSCALL_64_fastpath+0x12/0x76 ... Signed-off-by:Stephen Smalley <sds@tycho.nsa.gov> Reported-by:
Morten Stevens <mstevens@fedoraproject.org> Acked-by:
Hugh Dickins <hughd@google.com> Acked-by:
Paul Moore <paul@paul-moore.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by:
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Mel Gorman authored
Commit 92923ca3 ("mm: meminit: only set page reserved in the memblock region") broke memory hotplug which expects the memmap for newly added sections to be reserved until onlined by online_pages_range(). This patch marks hotplugged pages as reserved when adding new zones. Signed-off-by:
Mel Gorman <mgorman@suse.de> Reported-by:
David Vrabel <david.vrabel@citrix.com> Tested-by:
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Joseph Qi authored
When using a large volume, for example 9T volume with 2T already used, frequent creation of small files with O_DIRECT when the IO is not cluster aligned may clear sectors in the wrong place. This will cause filesystem corruption. This is because p_cpos is a u32. When calculating the corresponding sector it should be converted to u64 first, otherwise it may overflow. Signed-off-by:
Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by:
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David Kershner authored
The s-Par visornic driver, currently in staging, processes a queue being serviced by the an s-Par service partition. We can get a message that something has happened with the Service Partition, when that happens, we must not access the channel until we get a message that the service partition is back again. The visornic driver has a thread for processing the channel, when we get the message, we need to be able to park the thread and then resume it when the problem clears. We can do this with kthread_park and unpark but they are not exported from the kernel, this patch exports the needed functions. Signed-off-by:
David Kershner <david.kershner@unisys.com> Acked-by:
Ingo Molnar <mingo@kernel.org> Acked-by:
Neil Horman <nhorman@tuxdriver.com> Acked-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Richard Weinberger <richard.weinberger@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Jan Kara authored
fsnotify_clear_marks_by_group_flags() can race with fsnotify_destroy_marks() so that when fsnotify_destroy_mark_locked() drops mark_mutex, a mark from the list iterated by fsnotify_clear_marks_by_group_flags() can be freed and thus the next entry pointer we have cached may become stale and we dereference free memory. Fix the problem by first moving marks to free to a special private list and then always free the first entry in the special list. This method is safe even when entries from the list can disappear once we drop the lock. Signed-off-by:
Jan Kara <jack@suse.com> Reported-by:
Ashish Sangwan <a.sangwan@samsung.com> Reviewed-by:
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Sowmini Varadhan authored
Using a 64 bit constant generates "warning: integer constant is too large for 'long' type" on 32 bit platforms. Instead use ~0ul and BITS_PER_LONG. Detected by Andrew Morton on ARMD. Signed-off-by:
Sowmini Varadhan <sowmini.varadhan@oracle.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David S. Miller <davem@davemloft.net> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
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Konstantin Khlebnikov authored
This patch fixes creation of new kmem-caches after enabling sanity_checks for existing mergeable kmem-caches in runtime: before that patch creation fails because unique name in sysfs already taken by existing kmem-cache. Unlike other debug options this doesn't change object layout and could be enabled and disabled at any time. Signed-off-by:
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by:
Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Acked-by:
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Amanieu d'Antras authored
This function may copy the si_addr_lsb field to user mode when it hasn't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by:
Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Amanieu d'Antras authored
This function may copy the si_addr_lsb, si_lower and si_upper fields to user mode when they haven't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by:
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Amanieu d'Antras authored
This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: -
Joseph Qi authored
The "BUG_ON(list_empty(&osb->blocked_lock_list))" in ocfs2_downconvert_thread_do_work can be triggered in the following case: ocfs2dc has firstly saved osb->blocked_lock_count to local varibale processed, and then processes the dentry lockres. During the dentry put, it calls iput and then deletes rw, inode and open lockres from blocked list in ocfs2_mark_lockres_freeing. And this causes the variable `processed' to not reflect the number of blocked lockres to be processed, which triggers the BUG. Signed-off-by:
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Mel Gorman authored
Dave Hansen reported the following; My laptop has been behaving strangely with 4.2-rc2. Once I log in to my X session, I start getting all kinds of strange errors from applications and see this in my dmesg: VFS: file-max limit 8192 reached The problem is that the file-max is calculated before memory is fully initialised and miscalculates how much memory the kernel is using. This patch recalculates file-max after deferred memory initialisation. Note that using memory hotplug infrastructure would not have avoided this problem as the value is not recalculated after memory hot-add. 4.1: files_stat.max_files = 6582781 4.2-rc2: files_stat.max_files = 8192 4.2-rc2 patched: files_stat.max_files = 6562467 Small differences with the patch applied and 4.1 but not enough to matter. Signed-off-by:Dave Hansen <dave.hansen@intel.com> Cc: Nicolai Stange <nicstange@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Alex Ng <alexng@microsoft.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Nicolai Stange authored
Commit 0e1cc95b ("mm: meminit: finish initialisation of struct pages before basic setup") introduced a rwsem to signal completion of the initialization workers. Lockdep complains about possible recursive locking: ============================================= [ INFO: possible recursive locking detected ] 4.1.0-12802-g1dc51b82 #3 Not tainted --------------------------------------------- swapper/0/1 is trying to acquire lock: (pgdat_init_rwsem){++++.+}, at: [<ffffffff8424c7fb>] page_alloc_init_late+0xc7/0xe6 but task is already holding lock: (pgdat_init_rwsem){++++.+}, at: [<ffffffff8424c772>] page_alloc_init_late+0x3e/0xe6 Replace the rwsem by a completion together with an atomic "outstanding work counter". [peterz@infradead.org: Barrier removal on the grounds of being pointless] [mgorman@suse.de: Applied review feedback] Signed-off-by:
Nicolai Stange <nicstange@gmail.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Alex Ng <alexng@microsoft.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
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Mel Gorman authored
early_pfn_to_nid() historically was inherently not SMP safe but only used during boot which is inherently single threaded or during hotplug which is protected by a giant mutex. With deferred memory initialisation there was a thread-safe version introduced and the early_pfn_to_nid would trigger a BUG_ON if used unsafely. Memory hotplug hit that check. This patch makes early_pfn_to_nid introduces a lock to make it safe to use during hotplug. Signed-off-by:
Alex Ng <alexng@microsoft.com> Tested-by:
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Marcus Gelderie authored
A while back, the message queue implementation in the kernel was improved to use btrees to speed up retrieval of messages, in commit d6629859 ("ipc/mqueue: improve performance of send/recv"). That patch introducing the improved kernel handling of message queues (using btrees) has, as a by-product, changed the meaning of the QSIZE field in the pseudo-file created for the queue. Before, this field reflected the size of the user-data in the queue. Since, it also takes kernel data structures into account. For example, if 13 bytes of user data are in the queue, on my machine the file reports a size of 61 bytes. There was some discussion on this topic before (for example https://lkml.org/lkml/2014/10/1/115). Commenting on a th lkml, Michael Kerrisk gave the following background (https://lkml.org/lkml/2015/6/16/74): The pseudofiles in the mqueue filesystem (usually mounted at /dev/mqueue) expose fields with metadata describing a message queue. One of these fields, QSIZE, as originally implemented, showed the total number of bytes of user data in all messages in the message queue, and this feature was documented from the beginning in the mq_overview(7) page. In 3.5, some other (useful) work happened to break the user-space API in a couple of places, including the value exposed via QSIZE, which now includes a measure of kernel overhead bytes for the queue, a figure that renders QSIZE useless for its original purpose, since there's no way to deduce the number of overhead bytes consumed by the implementation. (The other user-space breakage was subsequently fixed.) This patch removes the accounting of kernel data structures in the queue. Reporting the size of these data-structures in the QSIZE field was a breaking change (see Michael's comment above). Without the QSIZE field reporting the total size of user-data in the queue, there is no way to deduce this number. It should be noted that the resource limit RLIMIT_MSGQUEUE is counted against the worst-case size of the queue (in both the old and the new implementation). Therefore, the kernel overhead accounting in QSIZE is not necessary to help the user understand the limitations RLIMIT imposes on the processes. Signed-off-by:
Marcus Gelderie <redmnic@gmail.com> Acked-by:
Doug Ledford <dledford@redhat.com> Acked-by:
Michael Kerrisk <mtk.manpages@gmail.com> Acked-by:
Davidlohr Bueso <dbueso@suse.de> Cc: David Howells <dhowells@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: John Duffy <jb_duffy@btinternet.com> Cc: Arto Bendiken <arto@bendiken.net> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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- 05 Aug, 2015 11 commits
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Jammy Zhou authored
The fw_version and feature_verion should be set correctly when the firmwares are loaded by SMU on Tonga/Carrzio/Iceland Signed-off-by:
Jammy Zhou <Jammy.Zhou@amd.com> Reviewed-by:
Christian König <christian.koenig@amd.com>
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Jammy Zhou authored
Signed-off-by:
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Jammy Zhou authored
Expose feature version to user space for RLC/MEC/MEC2 ucode as well v2: fix coding style Signed-off-by:
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Nicolas Iooss authored
gfx_v7_0_print_status contains a for loop on variable queue which does not update this variable between each iteration. This is bug is reported by clang while building allmodconfig LLVMLinux on x86_64: drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c:5126:19: error: variable 'queue' used in loop condition not modified in loop body [-Werror,-Wloop-analysis] for (queue = 0; queue < 8; i++) { ^~~~~ Fix this by incrementing variable queue instead of i in this loop. Signed-off-by:Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by:
Alex Deucher <alexander.deucher@amd.com>
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Alex Deucher authored
Always set num_rbs to 2 for CZ. The 1 RB parts are often harvest configs. The will get sorted out in mesa when we program PA_SC_RASTER_CONFIG[_1]. Acked-by:
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Paolo Bonzini: "Just two very small & simple patches" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON KVM: s390: Fix hang VCPU hang/loop regression
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Alex Williamson authored
The patch was munged on commit to re-order these tests resulting in excessive warnings when trying to do device assignment. Return to original ordering: https://lkml.org/lkml/2015/7/15/769 Fixes: 3e5d2fdc ("KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type") Signed-off-by:
Alex Williamson <alex.williamson@redhat.com> Reviewed-by:
Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Jean-Francois Moine authored
The commit 8c7a075d "drm/i2c: tda998x: use drm_hdmi_avi_infoframe_from_display_mode()" also uses hdmi_avi_infoframe_pack() to create the AVI infoframe. This function sets the checksum of the frame and this breaks the second calculation of the checksum done in tda998x_write_if(). Fixes: 8c7a075d ("drm/i2c: tda998x: use drm_hdmi_avi_infoframe_from_display_mode()") Signed-off-by:
Jean-Francois Moine <moinejf@free.fr> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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git://neil.brown.name/mdLinus Torvalds authored
Pull md fixes from Neil Brown: "Three more fixes for md in 4.2 Mostly corner-case stuff. One of these patches is for a CVE: CVE-2015-5697 I'm not convinced it is serious (data leak from CAP_SYS_ADMIN ioctl) but as people seem to want to back-port it, I've included a minimal version here. The remainder of that patch from Benjamin is code-cleanup and will arrive in the 4.3 merge window" * tag 'md/4.2-rc5-fixes' of git://neil.brown.name/md: md/raid5: don't let shrink_slab shrink too far. md: use kzalloc() when bitmap is disabled md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies
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git://linux-nfs.org/~bfields/linuxLinus Torvalds authored
Pull nfsd fixes from Bruce Fields. * 'for-4.2' of git://linux-nfs.org/~bfields/linux: nfsd: do nfs4_check_fh in nfs4_check_file instead of nfs4_check_olstateid nfsd: Fix a file leak on nfsd4_layout_setlease failure nfsd: Drop BUG_ON and ignore SECLABEL on absent filesystem
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Michal Hocko authored
Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e #2 schedule_timeout at ffffffff815ae5e5 #3 io_schedule_timeout at ffffffff815aad6a #4 bit_wait_io at ffffffff815abfc6 #5 __wait_on_bit at ffffffff815abda5 #6 wait_on_page_bit at ffffffff8111fd4f #7 shrink_page_list at ffffffff81135445 #8 shrink_inactive_list at ffffffff81135845 #9 shrink_lruvec at ffffffff81135ead #10 shrink_zone at ffffffff811360c3 #11 shrink_zones at ffffffff81136eff #12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384e ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f44 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. Cc: stable@vger.kernel.org # 3.9+ [tytso@mit.edu: corrected the control flow] Fixes: c3b94f44 ("memcg: further prevent OOM with too many dirty pages") Reported-by:
Nikolay Borisov <kernel@kyup.com> Signed-off-by:
Michal Hocko <mhocko@suse.cz> Signed-off-by:
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- 04 Aug, 2015 5 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull PCI fix from Bjorn Helgaas: "This is a trivial fix for a change that broke user program compilation (QEMU in this case)" * tag 'pci-v4.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Restore PCI_MSIX_FLAGS_BIRMASK definition
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git://anongit.freedesktop.org/drm-intelLinus Torvalds authored
Pull drm mst fixes from Daniel Vetter: "Special pull request for mst fixes since most of the patches touch code outside of i915 proper. DRM parts have also been reviewed by Thierry (nvidia) since Dave's enjoying vacations" * tag 'topic/mst-fixes-2015-08-04' of git://anongit.freedesktop.org/drm-intel: drm/atomic-helpers: Make encoder picking more robust drm/dp-mst: Remove debug WARN_ON drm/i915: Fixup dp mst encoder selection drm/atomic-helper: Add an atomice best_encoder callback
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds authored
Pull xen bug fixes from David Vrabel: - don't lose interrupts when offlining CPUs - fix gntdev oops during unmap - drop the balloon lock occasionally to allow domain create/destroy * tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/events/fifo: Handle linked events when closing a port xen: release lock occasionally during ballooning xen/gntdevt: Fix race condition in gntdev_release()
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Ross Lagerwall authored
An event channel bound to a CPU that was offlined may still be linked on that CPU's queue. If this event channel is closed and reused, subsequent events will be lost because the event channel is never unlinked and thus cannot be linked onto the correct queue. When a channel is closed and the event is still linked into a queue, ensure that it is unlinked before completing. If the CPU to which the event channel bound is online, spin until the event is handled by that CPU. If that CPU is offline, it can't handle the event, so clear the event queue during the close, dropping the events. This fixes the missing interrupts (and subsequent disk stalls etc.) when offlining a CPU. Signed-off-by:
Ross Lagerwall <ross.lagerwall@citrix.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuildLinus Torvalds authored
Pull kbuild fixes from Michal Marek: "Two fixes for kbuild: - The new ARCH_{CPP,A,C}FLAGS variables are reset before including the arch Makefile - Fix calling make modules_install twice when module compression is enabled" * 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: Makefile: Force gzip and xz on module install kbuild: Do not pick up ARCH_{CPP,A,C}FLAGS from the environment
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