commit e0c3e706e94deeaa75c5f9fb91cd24b3c71b4793 Author: Greg Kroah-Hartman Date: Sun Jul 11 12:46:41 2021 +0200 Linux 4.9.275 Link: https://lore.kernel.org/r/20210709131542.410636747@linuxfoundation.org Tested-by: Jon Hunter Tested-by: Shuah Khan Tested-by: Linux Kernel Functional Testing Tested-by: Guenter Roeck Tested-by: Florian Fainelli Signed-off-by: Greg Kroah-Hartman commit 01df0e31cb208a6b16b2d19e746a2d203cc24682 Author: Juergen Gross Date: Wed Jun 23 15:09:13 2021 +0200 xen/events: reset active flag for lateeoi events later commit 3de218ff39b9e3f0d453fe3154f12a174de44b25 upstream. In order to avoid a race condition for user events when changing cpu affinity reset the active flag only when EOI-ing the event. This is working fine as all user events are lateeoi events. Note that lateeoi_ack_mask_dynirq() is not modified as there is no explicit call to xen_irq_lateeoi() expected later. Cc: stable@vger.kernel.org Reported-by: Julien Grall Fixes: b6622798bc50b62 ("xen/events: avoid handling the same event on two cpus at the same time") Tested-by: Julien Grall Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210623130913.9405-1-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman commit 5d27e1503b17db8571a4e71b6146644ab29c18a7 Author: Petr Mladek Date: Thu Jun 24 18:39:48 2021 -0700 kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync() commit 5fa54346caf67b4b1b10b1f390316ae466da4d53 upstream. The system might hang with the following backtrace: schedule+0x80/0x100 schedule_timeout+0x48/0x138 wait_for_common+0xa4/0x134 wait_for_completion+0x1c/0x2c kthread_flush_work+0x114/0x1cc kthread_cancel_work_sync.llvm.16514401384283632983+0xe8/0x144 kthread_cancel_delayed_work_sync+0x18/0x2c xxxx_pm_notify+0xb0/0xd8 blocking_notifier_call_chain_robust+0x80/0x194 pm_notifier_call_chain_robust+0x28/0x4c suspend_prepare+0x40/0x260 enter_state+0x80/0x3f4 pm_suspend+0x60/0xdc state_store+0x108/0x144 kobj_attr_store+0x38/0x88 sysfs_kf_write+0x64/0xc0 kernfs_fop_write_iter+0x108/0x1d0 vfs_write+0x2f4/0x368 ksys_write+0x7c/0xec It is caused by the following race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync(): CPU0 CPU1 Context: Thread A Context: Thread B kthread_mod_delayed_work() spin_lock() __kthread_cancel_work() spin_unlock() del_timer_sync() kthread_cancel_delayed_work_sync() spin_lock() __kthread_cancel_work() spin_unlock() del_timer_sync() spin_lock() work->canceling++ spin_unlock spin_lock() queue_delayed_work() // dwork is put into the worker->delayed_work_list spin_unlock() kthread_flush_work() // flush_work is put at the tail of the dwork wait_for_completion() Context: IRQ kthread_delayed_work_timer_fn() spin_lock() list_del_init(&work->node); spin_unlock() BANG: flush_work is not longer linked and will never get proceed. The problem is that kthread_mod_delayed_work() checks work->canceling flag before canceling the timer. A simple solution is to (re)check work->canceling after __kthread_cancel_work(). But then it is not clear what should be returned when __kthread_cancel_work() removed the work from the queue (list) and it can't queue it again with the new @delay. The return value might be used for reference counting. The caller has to know whether a new work has been queued or an existing one was replaced. The proper solution is that kthread_mod_delayed_work() will remove the work from the queue (list) _only_ when work->canceling is not set. The flag must be checked after the timer is stopped and the remaining operations can be done under worker->lock. Note that kthread_mod_delayed_work() could remove the timer and then bail out. It is fine. The other canceling caller needs to cancel the timer as well. The important thing is that the queue (list) manipulation is done atomically under worker->lock. Link: https://lkml.kernel.org/r/20210610133051.15337-3-pmladek@suse.com Fixes: 9a6b06c8d9a220860468a ("kthread: allow to modify delayed kthread work") Signed-off-by: Petr Mladek Reported-by: Martin Liu Cc: Cc: Minchan Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Oleg Nesterov Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman commit 392cfdd660491857137c35cba7496fb7446afe4f Author: Petr Mladek Date: Thu Jun 24 18:39:45 2021 -0700 kthread_worker: split code for canceling the delayed work timer commit 34b3d5344719d14fd2185b2d9459b3abcb8cf9d8 upstream. Patch series "kthread_worker: Fix race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync()". This patchset fixes the race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync() including proper return value handling. This patch (of 2): Simple code refactoring as a preparation step for fixing a race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync(). It does not modify the existing behavior. Link: https://lkml.kernel.org/r/20210610133051.15337-2-pmladek@suse.com Signed-off-by: Petr Mladek Cc: Cc: Martin Liu Cc: Minchan Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Oleg Nesterov Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman commit 22226752e45934480f63cc8e43abb13b7e59f4fb Author: Christian König Date: Fri Jun 11 14:34:50 2021 +0200 drm/nouveau: fix dma_address check for CPU/GPU sync [ Upstream commit d330099115597bbc238d6758a4930e72b49ea9ba ] AGP for example doesn't have a dma_address array. Signed-off-by: Christian König Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20210614110517.1624-1-christian.koenig@amd.com Signed-off-by: Sasha Levin commit 8b289e6d55a6dc2341020bc632fe7bddcd5a07d3 Author: ManYi Li Date: Fri Jun 11 17:44:02 2021 +0800 scsi: sr: Return appropriate error code when disk is ejected [ Upstream commit 7dd753ca59d6c8cc09aa1ed24f7657524803c7f3 ] Handle a reported media event code of 3. This indicates that the media has been removed from the drive and user intervention is required to proceed. Return DISK_EVENT_EJECT_REQUEST in that case. Link: https://lore.kernel.org/r/20210611094402.23884-1-limanyi@uniontech.com Signed-off-by: ManYi Li Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin commit c52e6f64804267cc8c9f26ab41588eeeae6fb9a7 Author: Hugh Dickins Date: Thu Jun 24 18:39:52 2021 -0700 mm, futex: fix shared futex pgoff on shmem huge page [ Upstream commit fe19bd3dae3d15d2fbfdb3de8839a6ea0fe94264 ] If more than one futex is placed on a shmem huge page, it can happen that waking the second wakes the first instead, and leaves the second waiting: the key's shared.pgoff is wrong. When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when generating futex_key"), the only shared huge pages came from hugetlbfs, and the code added to deal with its exceptional page->index was put into hugetlb source. Then that was missed when 4.8 added shmem huge pages. page_to_pgoff() is what others use for this nowadays: except that, as currently written, it gives the right answer on hugetlbfs head, but nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific hugetlb_basepage_index() on PageHuge tails as well as on head. Yes, it's unconventional to declare hugetlb_basepage_index() there in pagemap.h, rather than in hugetlb.h; but I do not expect anything but page_to_pgoff() ever to need it. [akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope] Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Reported-by: Neel Natu Signed-off-by: Hugh Dickins Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Thomas Gleixner Cc: "Kirill A. Shutemov" Cc: Zhang Yi Cc: Mel Gorman Cc: Mike Kravetz Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Darren Hart Cc: Davidlohr Bueso Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Note on stable backport: leave redundant #include in kernel/futex.c, to avoid conflict over the header files included. Resolved trivial conflicts in include/linux/hugetlb.h. Signed-off-by: Hugh Dickins Signed-off-by: Sasha Levin commit 07cc82b921bc60194bdc4a2ccea7d69f2d789348 Author: Yang Shi Date: Tue Jun 15 18:24:07 2021 -0700 mm: thp: replace DEBUG_VM BUG with VM_WARN when unmap fails for split [ Upstream commit 504e070dc08f757bccaed6d05c0f53ecbfac8a23 ] When debugging the bug reported by Wang Yugui [1], try_to_unmap() may fail, but the first VM_BUG_ON_PAGE() just checks page_mapcount() however it may miss the failure when head page is unmapped but other subpage is mapped. Then the second DEBUG_VM BUG() that check total mapcount would catch it. This may incur some confusion. As this is not a fatal issue, so consolidate the two DEBUG_VM checks into one VM_WARN_ON_ONCE_PAGE(). [1] https://lore.kernel.org/linux-mm/20210412180659.B9E3.409509F4@e16-tech.com/ Link: https://lkml.kernel.org/r/d0f0db68-98b8-ebfb-16dc-f29df24cf012@google.com Signed-off-by: Yang Shi Reviewed-by: Zi Yan Acked-by: Kirill A. Shutemov Signed-off-by: Hugh Dickins Cc: Alistair Popple Cc: Jan Kara Cc: Jue Wang Cc: "Matthew Wilcox (Oracle)" Cc: Miaohe Lin Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Peter Xu Cc: Ralph Campbell Cc: Shakeel Butt Cc: Wang Yugui Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Note on stable backport: fixed up variables, split_queue_lock, tree_lock in split_huge_page_to_list(); adapted to early version of unmap_page(). Signed-off-by: Hugh Dickins Signed-off-by: Sasha Levin commit 2b123e354eff9d24a5e27efb2cb70f2720509f92 Author: Alex Shi Date: Fri Dec 18 14:01:31 2020 -0800 mm: add VM_WARN_ON_ONCE_PAGE() macro [ Upstream commit a4055888629bc0467d12d912cd7c90acdf3d9b12 part ] Add VM_WARN_ON_ONCE_PAGE() macro. Link: https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi Acked-by: Michal Hocko Acked-by: Hugh Dickins Acked-by: Johannes Weiner Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Note on stable backport: original commit was titled mm/memcg: warning on !memcg after readahead page charged which included uses of this macro in mm/memcontrol.c: here omitted. Signed-off-by: Hugh Dickins Signed-off-by: Sasha Levin commit 88a899fa2032b34ef3ac5dae3c70c8394fa5287c Author: Michal Hocko Date: Thu Apr 5 16:25:30 2018 -0700 include/linux/mmdebug.h: make VM_WARN* non-rvals [ Upstream commit 91241681c62a5a690c88eb2aca027f094125eaac ] At present the construct if (VM_WARN(...)) will compile OK with CONFIG_DEBUG_VM=y and will fail with CONFIG_DEBUG_VM=n. The reason is that VM_{WARN,BUG}* have always been special wrt. {WARN/BUG}* and never generate any code when DEBUG_VM is disabled. So we cannot really use it in conditionals. We considered changing things so that this construct works in both cases but that might cause unwanted code generation with CONFIG_DEBUG_VM=n. It is safer and simpler to make the build fail in both cases. [akpm@linux-foundation.org: changelog] Signed-off-by: Michal Hocko Reviewed-by: Andrew Morton Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin