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Previously, there was a bug where user could see stale buffer cache (e.g, 512B) attached in the 4KB-sized pager cache, when the block size was changed from 512B to 4KB. That was fixed by: commit 5db470e ("loop: drop caches if offset or block_size are changed") But, there were some regression reports saying the fix returns EAGAIN easily. So, this patch removes previously added EAGAIN condition, nrpages != 0. Instead, it changes the flow like this: - sync_blockdev() - blk_mq_freeze_queue() : change the loop configuration - blk_mq_unfreeze_queue() - sync_blockdev() - invalidate_bdev() After invalidating the buffer cache, we must see the full valid 4KB page. Additional concern came from Bart in which we can lose some data when changing the lo_offset. In that case, this patch adds: - sync_blockdev() - blk_set_queue_dying - blk_mq_freeze_queue() : change the loop configuration - blk_mq_unfreeze_queue() - blk_queue_flag_clear(QUEUE_FLAG_DYING); - sync_blockdev() - invalidate_bdev() Report: https://bugs.chromium.org/p/chromium/issues/detail?id=938958#c38 Cc: <stable@vger.kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Bart Van Assche <bvanassche@acm.org> Fixes: 5db470e ("loop: drop caches if offset or block_size are changed") Reported-by: Gwendal Grignou <gwendal@chromium.org> Reported-by: grygorii tertychnyi <gtertych@cisco.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
…writing some files would fail when cluster.idx did not add
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Jul 16, 2020
PID: 257 TASK: ecdd0000 CPU: 0 COMMAND: "init" #0 [<c0b420ec>] (__schedule) from [<c0b423c8>] #1 [<c0b423c8>] (schedule) from [<c0b459d4>] #2 [<c0b459d4>] (rwsem_down_read_failed) from [<c0b44fa0>] #3 [<c0b44fa0>] (down_read) from [<c044233c>] #4 [<c044233c>] (f2fs_truncate_blocks) from [<c0442890>] #5 [<c0442890>] (f2fs_truncate) from [<c044d408>] #6 [<c044d408>] (f2fs_evict_inode) from [<c030be18>] #7 [<c030be18>] (evict) from [<c030a558>] #8 [<c030a558>] (iput) from [<c047c600>] #9 [<c047c600>] (f2fs_sync_node_pages) from [<c0465414>] #10 [<c0465414>] (f2fs_write_checkpoint) from [<c04575f4>] #11 [<c04575f4>] (f2fs_sync_fs) from [<c0441918>] #12 [<c0441918>] (f2fs_do_sync_file) from [<c0441098>] #13 [<c0441098>] (f2fs_sync_file) from [<c0323fa0>] #14 [<c0323fa0>] (vfs_fsync_range) from [<c0324294>] #15 [<c0324294>] (do_fsync) from [<c0324014>] #16 [<c0324014>] (sys_fsync) from [<c0108bc0>] This can be caused by flush_dirty_inode() in f2fs_sync_node_pages() where iput() requires f2fs_lock_op() again resulting in livelock. Reported-by: Zhiguo Niu <Zhiguo.Niu@unisoc.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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https://bugzilla.kernel.org/show_bug.cgi?id=208565 PID: 257 TASK: ecdd0000 CPU: 0 COMMAND: "init" #0 [<c0b420ec>] (__schedule) from [<c0b423c8>] #1 [<c0b423c8>] (schedule) from [<c0b459d4>] #2 [<c0b459d4>] (rwsem_down_read_failed) from [<c0b44fa0>] #3 [<c0b44fa0>] (down_read) from [<c044233c>] #4 [<c044233c>] (f2fs_truncate_blocks) from [<c0442890>] #5 [<c0442890>] (f2fs_truncate) from [<c044d408>] #6 [<c044d408>] (f2fs_evict_inode) from [<c030be18>] #7 [<c030be18>] (evict) from [<c030a558>] #8 [<c030a558>] (iput) from [<c047c600>] #9 [<c047c600>] (f2fs_sync_node_pages) from [<c0465414>] #10 [<c0465414>] (f2fs_write_checkpoint) from [<c04575f4>] #11 [<c04575f4>] (f2fs_sync_fs) from [<c0441918>] #12 [<c0441918>] (f2fs_do_sync_file) from [<c0441098>] #13 [<c0441098>] (f2fs_sync_file) from [<c0323fa0>] #14 [<c0323fa0>] (vfs_fsync_range) from [<c0324294>] #15 [<c0324294>] (do_fsync) from [<c0324014>] #16 [<c0324014>] (sys_fsync) from [<c0108bc0>] This can be caused by flush_dirty_inode() in f2fs_sync_node_pages() where iput() requires f2fs_lock_op() again resulting in livelock. Reported-by: Zhiguo Niu <Zhiguo.Niu@unisoc.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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Aug 14, 2020
The recently introduced CHOOSE_HYP_SYM() macro picks one symbol or another, depending on whether the kernel run as a VHE hypervisor or not. For that, it uses the has_vhe() helper, which is itself implemented as a final capability. Unfortunately, __copy_hyp_vect_bpi now indirectly uses CHOOSE_HYP_SYM to get the __bp_harden_hyp_vecs symbol, using has_vhe() in the process. At this stage, the capability isn't final and things explode: [ 0.000000] ACPI: SRAT not present [ 0.000000] percpu: Embedded 34 pages/cpu s101264 r8192 d29808 u139264 [ 0.000000] Detected PIPT I-cache on CPU0 [ 0.000000] ------------[ cut here ]------------ [ 0.000000] kernel BUG at arch/arm64/include/asm/cpufeature.h:459! [ 0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00080-gd630681366e5 #1388 [ 0.000000] pstate: 80000085 (Nzcv daIf -PAN -UAO BTYPE=--) [ 0.000000] pc : check_branch_predictor+0x3a4/0x408 [ 0.000000] lr : check_branch_predictor+0x2a4/0x408 [ 0.000000] sp : ffff800011693e90 [ 0.000000] x29: ffff800011693e90 x28: ffff8000116a1530 [ 0.000000] x27: ffff8000112c1008 x26: ffff800010ca6ff8 [ 0.000000] x25: ffff8000112c1000 x24: ffff8000116a1320 [ 0.000000] x23: 0000000000000000 x22: ffff8000112c1000 [ 0.000000] x21: ffff800010177120 x20: ffff8000116ae108 [ 0.000000] x19: 0000000000000000 x18: ffff800011965c90 [ 0.000000] x17: 0000000000022000 x16: 0000000000000003 [ 0.000000] x15: 00000000ffffffff x14: ffff8000118c3a38 [ 0.000000] x13: 0000000000000021 x12: 0000000000000022 [ 0.000000] x11: d37a6f4de9bd37a7 x10: 000000000000001d [ 0.000000] x9 : 0000000000000000 x8 : ffff800011f8dad8 [ 0.000000] x7 : ffff800011965ad0 x6 : 0000000000000003 [ 0.000000] x5 : 0000000000000000 x4 : 0000000000000000 [ 0.000000] x3 : 0000000000000100 x2 : 0000000000000004 [ 0.000000] x1 : ffff8000116ae148 x0 : 0000000000000000 [ 0.000000] Call trace: [ 0.000000] check_branch_predictor+0x3a4/0x408 [ 0.000000] update_cpu_capabilities+0x84/0x138 [ 0.000000] init_cpu_features+0x2c0/0x2d8 [ 0.000000] cpuinfo_store_boot_cpu+0x54/0x64 [ 0.000000] smp_prepare_boot_cpu+0x2c/0x60 [ 0.000000] start_kernel+0x16c/0x574 [ 0.000000] Code: 17ffffc7 91010281 14000198 17ffffca (d4210000) This is addressed using a two-fold process: - Replace has_vhe() with is_kernel_in_hyp_mode(), which tests whether we are running at EL2. - Make CHOOSE_HYP_SYM() return an *undefined* symbol when compiled in the nVHE hypervisor, as we really should never use this helper in the nVHE-specific code. With this in place, we're back to a bootable kernel again. Fixes: b877e98 ("KVM: arm64: Build hyp-entry.S separately for VHE/nVHE") Signed-off-by: Marc Zyngier <maz@kernel.org>
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When watchdog device is being registered, it calls misc_register that makes watchdog available for systemd to open. This is a data race scenario, because when device is open it may still have device struct not initialized - this in turn causes a crash. This patch moves device initialization before misc_register call and it solves the problem printed below. ------------[ cut here ]------------ WARNING: CPU: 3 PID: 1 at lib/kobject.c:612 kobject_get+0x50/0x54 kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is being called. Modules linked in: k2_reset_status(O) davinci_wdt(+) sfn_platform_hwbcn(O) fsmddg_sfn(O) clk_misc_mmap(O) clk_sw_bcn(O) fsp_reset(O) cma_mod(O) slave_sup_notif(O) fpga_master(O) latency(O+) evnotify(O) enable_arm_pmu(O) xge(O) rio_mport_cdev br_netfilter bridge stp llc nvrd_checksum(O) ipv6 CPU: 3 PID: 1 Comm: systemd Tainted: G O 4.19.113-g2579778-fsm4_k2 #1 Hardware name: Keystone [<c02126c4>] (unwind_backtrace) from [<c020da94>] (show_stack+0x18/0x1c) [<c020da94>] (show_stack) from [<c07f87d8>] (dump_stack+0xb4/0xe8) [<c07f87d8>] (dump_stack) from [<c0221f70>] (__warn+0xfc/0x114) [<c0221f70>] (__warn) from [<c0221fd8>] (warn_slowpath_fmt+0x50/0x74) [<c0221fd8>] (warn_slowpath_fmt) from [<c07fd394>] (kobject_get+0x50/0x54) [<c07fd394>] (kobject_get) from [<c0602ce8>] (get_device+0x1c/0x24) [<c0602ce8>] (get_device) from [<c06961e0>] (watchdog_open+0x90/0xf0) [<c06961e0>] (watchdog_open) from [<c06001dc>] (misc_open+0x130/0x17c) [<c06001dc>] (misc_open) from [<c0388228>] (chrdev_open+0xec/0x1a8) [<c0388228>] (chrdev_open) from [<c037fa98>] (do_dentry_open+0x204/0x3cc) [<c037fa98>] (do_dentry_open) from [<c0391e2c>] (path_openat+0x330/0x1148) [<c0391e2c>] (path_openat) from [<c0394518>] (do_filp_open+0x78/0xec) [<c0394518>] (do_filp_open) from [<c0381100>] (do_sys_open+0x130/0x1f4) [<c0381100>] (do_sys_open) from [<c0201000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xd2ceffa8 to 0xd2cefff0) ffa0: b6f69968 00000000 ffffff9c b6ebd210 000a0001 00000000 ffc0: b6f69968 00000000 00000000 00000142 fffffffd ffffffff 00b65530 bed7bb78 ffe0: 00000142 bed7ba70 b6cc2503 b6cc41d6 ---[ end trace 7b16eb105513974f ]--- ------------[ cut here ]------------ WARNING: CPU: 3 PID: 1 at lib/refcount.c:153 kobject_get+0x24/0x54 refcount_t: increment on 0; use-after-free. Modules linked in: k2_reset_status(O) davinci_wdt(+) sfn_platform_hwbcn(O) fsmddg_sfn(O) clk_misc_mmap(O) clk_sw_bcn(O) fsp_reset(O) cma_mod(O) slave_sup_notif(O) fpga_master(O) latency(O+) evnotify(O) enable_arm_pmu(O) xge(O) rio_mport_cdev br_netfilter bridge stp llc nvrd_checksum(O) ipv6 CPU: 3 PID: 1 Comm: systemd Tainted: G W O 4.19.113-g2579778-fsm4_k2 #1 Hardware name: Keystone [<c02126c4>] (unwind_backtrace) from [<c020da94>] (show_stack+0x18/0x1c) [<c020da94>] (show_stack) from [<c07f87d8>] (dump_stack+0xb4/0xe8) [<c07f87d8>] (dump_stack) from [<c0221f70>] (__warn+0xfc/0x114) [<c0221f70>] (__warn) from [<c0221fd8>] (warn_slowpath_fmt+0x50/0x74) [<c0221fd8>] (warn_slowpath_fmt) from [<c07fd368>] (kobject_get+0x24/0x54) [<c07fd368>] (kobject_get) from [<c0602ce8>] (get_device+0x1c/0x24) [<c0602ce8>] (get_device) from [<c06961e0>] (watchdog_open+0x90/0xf0) [<c06961e0>] (watchdog_open) from [<c06001dc>] (misc_open+0x130/0x17c) [<c06001dc>] (misc_open) from [<c0388228>] (chrdev_open+0xec/0x1a8) [<c0388228>] (chrdev_open) from [<c037fa98>] (do_dentry_open+0x204/0x3cc) [<c037fa98>] (do_dentry_open) from [<c0391e2c>] (path_openat+0x330/0x1148) [<c0391e2c>] (path_openat) from [<c0394518>] (do_filp_open+0x78/0xec) [<c0394518>] (do_filp_open) from [<c0381100>] (do_sys_open+0x130/0x1f4) [<c0381100>] (do_sys_open) from [<c0201000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xd2ceffa8 to 0xd2cefff0) ffa0: b6f69968 00000000 ffffff9c b6ebd210 000a0001 00000000 ffc0: b6f69968 00000000 00000000 00000142 fffffffd ffffffff 00b65530 bed7bb78 ffe0: 00000142 bed7ba70 b6cc2503 b6cc41d6 ---[ end trace 7b16eb1055139750 ]--- Fixes: 72139df ("watchdog: Fix the race between the release of watchdog_core_data and cdev") Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Krzysztof Sobota <krzysztof.sobota@nokia.com> Link: https://lore.kernel.org/r/20200717103109.14660-1-krzysztof.sobota@nokia.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
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Yonghong Song says: ==================== Andrii raised a concern that current uapi for bpf iterator map element is a little restrictive and not suitable for future potential complex customization. This is a valid suggestion, considering people may indeed add more complex custimization to the iterator, e.g., cgroup_id + user_id, etc. for task or task_file. Another example might be map_id plus additional control so that the bpf iterator may bail out a bucket earlier if a bucket has too many elements which may hold lock too long and impact other parts of systems. Patch #1 modified uapi with kernel changes. Patch #2 adjusted libbpf api accordingly. Changelogs: v3 -> v4: . add a forward declaration of bpf_iter_link_info in tools/lib/bpf/bpf.h in case that libbpf is built against not-latest uapi bpf.h. . target the patch set to "bpf" instead of "bpf-next" v2 -> v3: . undo "not reject iter_info.map.map_fd == 0" from v1. In the future map_fd may become optional, so let us use map_fd == 0 indicating the map_fd is not set by user space. . add link_info_len to bpf_iter_attach_opts to ensure always correct link_info_len from user. Otherwise, libbpf may deduce incorrect link_info_len if it uses different uapi header than the user app. v1 -> v2: . ensure link_create target_fd/flags == 0 since they are not used. (Andrii) . if either of iter_info ptr == 0 or iter_info_len == 0, but not both, return error to user space. (Andrii) . do not reject iter_info.map.map_fd == 0, go ahead to use it trying to get a map reference since the map_fd is required for map_elem iterator. . use bpf_iter_link_info in bpf_iter_attach_opts instead of map_fd. this way, user space is responsible to set up bpf_iter_link_info and libbpf just passes the data to the kernel, simplifying libbpf design. (Andrii) ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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…ression [BUG] There is a bug report of NULL pointer dereference caused in compress_file_extent(): Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs] NIP [c008000006dd4d34] compress_file_range.constprop.41+0x75c/0x8a0 [btrfs] LR [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs] Call Trace: [c000000c69093b00] [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs] (unreliable) [c000000c69093bd0] [c008000006dd4ebc] async_cow_start+0x44/0xa0 [btrfs] [c000000c69093c10] [c008000006e14824] normal_work_helper+0xdc/0x598 [btrfs] [c000000c69093c80] [c0000000001608c0] process_one_work+0x2c0/0x5b0 [c000000c69093d10] [c000000000160c38] worker_thread+0x88/0x660 [c000000c69093db0] [c00000000016b55c] kthread+0x1ac/0x1c0 [c000000c69093e20] [c00000000000b660] ret_from_kernel_thread+0x5c/0x7c ---[ end trace f16954aa20d822f6 ]--- [CAUSE] For the following execution route of compress_file_range(), it's possible to hit NULL pointer dereference: compress_file_extent() |- pages = NULL; |- start = async_chunk->start = 0; |- end = async_chunk = 4095; |- nr_pages = 1; |- inode_need_compress() == false; <<< Possible, see later explanation | Now, we have nr_pages = 1, pages = NULL |- cont: |- ret = cow_file_range_inline(); |- if (ret <= 0) { |- for (i = 0; i < nr_pages; i++) { |- WARN_ON(pages[i]->mapping); <<< Crash To enter above call execution branch, we need the following race: Thread 1 (chattr) | Thread 2 (writeback) --------------------------+------------------------------ | btrfs_run_delalloc_range | |- inode_need_compress = true | |- cow_file_range_async() btrfs_ioctl_set_flag() | |- binode_flags |= | BTRFS_INODE_NOCOMPRESS | | compress_file_range() | |- inode_need_compress = false | |- nr_page = 1 while pages = NULL | | Then hit the crash [FIX] This patch will fix it by checking @pages before doing accessing it. This patch is only designed as a hot fix and easy to backport. More elegant fix may make btrfs only check inode_need_compress() once to avoid such race, but that would be another story. Reported-by: Luciano Chavez <chavez@us.ibm.com> Fixes: 4d3a800 ("btrfs: merge nr_pages input and output parameter in compress_pages") CC: stable@vger.kernel.org # 4.14.x: cecc8d9: btrfs: Move free_pages_out label in inline extent handling branch in compress_file_range CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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The routine cma_init_reserved_areas is designed to activate all reserved cma areas. It quits when it first encounters an error. This can leave some areas in a state where they are reserved but not activated. There is no feedback to code which performed the reservation. Attempting to allocate memory from areas in such a state will result in a BUG. Modify cma_init_reserved_areas to always attempt to activate all areas. The called routine, cma_activate_area is responsible for leaving the area in a valid state. No one is making active use of returned error codes, so change the routine to void. How to reproduce: This example uses kernelcore, hugetlb and cma as an easy way to reproduce. However, this is a more general cma issue. Two node x86 VM 16GB total, 8GB per node Kernel command line parameters, kernelcore=4G hugetlb_cma=8G Related boot time messages, hugetlb_cma: reserve 8192 MiB, up to 4096 MiB per node cma: Reserved 4096 MiB at 0x0000000100000000 hugetlb_cma: reserved 4096 MiB on node 0 cma: Reserved 4096 MiB at 0x0000000300000000 hugetlb_cma: reserved 4096 MiB on node 1 cma: CMA area hugetlb could not be activated # echo 8 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI ... Call Trace: bitmap_find_next_zero_area_off+0x51/0x90 cma_alloc+0x1a5/0x310 alloc_fresh_huge_page+0x78/0x1a0 alloc_pool_huge_page+0x6f/0xf0 set_max_huge_pages+0x10c/0x250 nr_hugepages_store_common+0x92/0x120 ? __kmalloc+0x171/0x270 kernfs_fop_write+0xc1/0x1a0 vfs_write+0xc7/0x1f0 ksys_write+0x5f/0xe0 do_syscall_64+0x4d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: c64be2b ("drivers: add Contiguous Memory Allocator") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200730163123.6451-1-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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syzbot reported this issue where in the vsock_poll() we find the socket state at TCP_ESTABLISHED, but 'transport' is null: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 8227 Comm: syz-executor.2 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vsock_poll+0x75a/0x8e0 net/vmw_vsock/af_vsock.c:1038 Call Trace: sock_poll+0x159/0x460 net/socket.c:1266 vfs_poll include/linux/poll.h:90 [inline] do_pollfd fs/select.c:869 [inline] do_poll fs/select.c:917 [inline] do_sys_poll+0x607/0xd40 fs/select.c:1011 __do_sys_poll fs/select.c:1069 [inline] __se_sys_poll fs/select.c:1057 [inline] __x64_sys_poll+0x18c/0x440 fs/select.c:1057 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can happen if the TCP_ESTABLISHED state is set after we read the vsk->transport in the vsock_poll(). We could put barriers to synchronize, but this can only happen during connection setup, so we can simply check that 'transport' is valid. Fixes: c0cfa2d ("vsock: add multi-transports support") Reported-and-tested-by: syzbot+a61bac2fcc1a7c6623fe@syzkaller.appspotmail.com Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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…ble for NFS commit 0688e64 ("NFS: Allow signal interruption of NFS4ERR_DELAYed operations") introduces nfs4_delay_interruptible which also needs an _unsafe version to avoid the following call trace for the same reason explained in commit 416ad3c ("freezer: add unsafe versions of freezable helpers for NFS") CPU: 4 PID: 3968 Comm: rm Tainted: G W 5.8.0-rc4 #1 Hardware name: Marvell OcteonTX CN96XX board (DT) Call trace: dump_backtrace+0x0/0x1dc show_stack+0x20/0x30 dump_stack+0xdc/0x150 debug_check_no_locks_held+0x98/0xa0 nfs4_delay_interruptible+0xd8/0x120 nfs4_handle_exception+0x130/0x170 nfs4_proc_rmdir+0x8c/0x220 nfs_rmdir+0xa4/0x360 vfs_rmdir.part.0+0x6c/0x1b0 do_rmdir+0x18c/0x210 __arm64_sys_unlinkat+0x64/0x7c el0_svc_common.constprop.0+0x7c/0x110 do_el0_svc+0x24/0xa0 el0_sync_handler+0x13c/0x1b8 el0_sync+0x158/0x180 Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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Aug 17, 2020
…card() If create a loop device with a backing NVMe SSD, current loop device driver doesn't correctly set its queue's limits.discard_granularity and leaves it as 0. If a discard request at LBA 0 on this loop device, in __blkdev_issue_discard() the calculated req_sects will be 0, and a zero length discard request will trigger a BUG() panic in generic block layer code at block/blk-mq.c:563. [ 955.565006][ C39] ------------[ cut here ]------------ [ 955.559660][ C39] invalid opcode: 0000 [#1] SMP NOPTI [ 955.622171][ C39] CPU: 39 PID: 248 Comm: ksoftirqd/39 Tainted: G E 5.8.0-default+ #40 [ 955.622171][ C39] Hardware name: Lenovo ThinkSystem SR650 -[7X05CTO1WW]-/-[7X05CTO1WW]-, BIOS -[IVE160M-2.70]- 07/17/2020 [ 955.622175][ C39] RIP: 0010:blk_mq_end_request+0x107/0x110 [ 955.622177][ C39] Code: 48 8b 03 e9 59 ff ff ff 48 89 df 5b 5d 41 5c e9 9f ed ff ff 48 8b 35 98 3c f4 00 48 83 c7 10 48 83 c6 19 e8 cb 56 c9 ff eb cb <0f> 0b 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 54 [ 955.622179][ C39] RSP: 0018:ffffb1288701fe28 EFLAGS: 00010202 [ 955.749277][ C39] RAX: 0000000000000001 RBX: ffff956fffba5080 RCX: 0000000000004003 [ 955.749278][ C39] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 [ 955.749279][ C39] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 955.749279][ C39] R10: ffffb1288701fd28 R11: 0000000000000001 R12: ffffffffa8e05160 [ 955.749280][ C39] R13: 0000000000000004 R14: 0000000000000004 R15: ffffffffa7ad3a1e [ 955.749281][ C39] FS: 0000000000000000(0000) GS:ffff95bfbda00000(0000) knlGS:0000000000000000 [ 955.749282][ C39] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 955.749282][ C39] CR2: 00007f6f0ef766a8 CR3: 0000005a37012002 CR4: 00000000007606e0 [ 955.749283][ C39] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 955.749284][ C39] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 955.749284][ C39] PKRU: 55555554 [ 955.749285][ C39] Call Trace: [ 955.749290][ C39] blk_done_softirq+0x99/0xc0 [ 957.550669][ C39] __do_softirq+0xd3/0x45f [ 957.550677][ C39] ? smpboot_thread_fn+0x2f/0x1e0 [ 957.550679][ C39] ? smpboot_thread_fn+0x74/0x1e0 [ 957.550680][ C39] ? smpboot_thread_fn+0x14e/0x1e0 [ 957.550684][ C39] run_ksoftirqd+0x30/0x60 [ 957.550687][ C39] smpboot_thread_fn+0x149/0x1e0 [ 957.886225][ C39] ? sort_range+0x20/0x20 [ 957.886226][ C39] kthread+0x137/0x160 [ 957.886228][ C39] ? kthread_park+0x90/0x90 [ 957.886231][ C39] ret_from_fork+0x22/0x30 [ 959.117120][ C39] ---[ end trace 3dacdac97e2ed164 ]--- This is the procedure to reproduce the panic, # modprobe scsi_debug delay=0 dev_size_mb=2048 max_queue=1 # losetup -f /dev/nvme0n1 --direct-io=on # blkdiscard /dev/loop0 -o 0 -l 0x200 This patch fixes the issue by checking q->limits.discard_granularity in __blkdev_issue_discard() before composing the discard bio. If the value is 0, then prints a warning oops information and returns -EOPNOTSUPP to the caller to indicate that this buggy device driver doesn't support discard request. Fixes: 9b15d10 ("block: improve discard bio alignment in __blkdev_issue_discard()") Fixes: c52abf5 ("loop: Better discard support for block devices") Reported-and-suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Enzo Matsumiya <ematsumiya@suse.com> Cc: Evan Green <evgreen@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Xiao Ni <xni@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
jaegeuk
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Aug 17, 2020
The restart handler is executed during the shutdown phase which is atomic/irq-less. The i2c framework supports atomic transfers since commit 63b9698 ("i2c: core: introduce callbacks for atomic transfers") to address this use case. Using i2c regmap in that situation is not allowed: [ 165.177465] [ BUG: Invalid wait context ] [ 165.181479] 5.8.0-rc3-00003-g0e9088558027-dirty #11 Not tainted [ 165.187400] ----------------------------- [ 165.191410] systemd-shutdow/1 is trying to lock: [ 165.196030] d85b4438 (rn5t618:170:(&rn5t618_regmap_config)->lock){+.+.}-{3:3}, at: regmap_update_bits_base+0x30/0x70 [ 165.206573] other info that might help us debug this: [ 165.211625] context-{4:4} [ 165.214248] 2 locks held by systemd-shutdow/1: [ 165.218691] #0: c131c47c (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x90/0x204 [ 165.227405] #1: c131efb4 (rcu_read_lock){....}-{1:2}, at: __atomic_notifier_call_chain+0x0/0x118 [ 165.236288] stack backtrace: [ 165.239174] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.8.0-rc3-00003-g0e9088558027-dirty #11 [ 165.248220] Hardware name: Freescale i.MX6 SoloLite (Device Tree) [ 165.254330] [<c0112110>] (unwind_backtrace) from [<c010bfa0>] (show_stack+0x10/0x14) [ 165.262084] [<c010bfa0>] (show_stack) from [<c058093c>] (dump_stack+0xe8/0x120) [ 165.269407] [<c058093c>] (dump_stack) from [<c01835a4>] (__lock_acquire+0x81c/0x2ca0) [ 165.277246] [<c01835a4>] (__lock_acquire) from [<c0186344>] (lock_acquire+0xe4/0x490) [ 165.285090] [<c0186344>] (lock_acquire) from [<c0c98638>] (__mutex_lock+0x74/0x954) [ 165.292756] [<c0c98638>] (__mutex_lock) from [<c0c98f34>] (mutex_lock_nested+0x1c/0x24) [ 165.300769] [<c0c98f34>] (mutex_lock_nested) from [<c07593ec>] (regmap_update_bits_base+0x30/0x70) [ 165.309741] [<c07593ec>] (regmap_update_bits_base) from [<c076b838>] (rn5t618_trigger_poweroff_sequence+0x34/0x64) [ 165.320097] [<c076b838>] (rn5t618_trigger_poweroff_sequence) from [<c076b874>] (rn5t618_restart+0xc/0x2c) [ 165.329669] [<c076b874>] (rn5t618_restart) from [<c01514f8>] (notifier_call_chain+0x48/0x80) [ 165.338113] [<c01514f8>] (notifier_call_chain) from [<c01516a8>] (__atomic_notifier_call_chain+0x70/0x118) [ 165.347770] [<c01516a8>] (__atomic_notifier_call_chain) from [<c0151768>] (atomic_notifier_call_chain+0x18/0x20) [ 165.357949] [<c0151768>] (atomic_notifier_call_chain) from [<c010a828>] (machine_restart+0x68/0x80) [ 165.367001] [<c010a828>] (machine_restart) from [<c0153224>] (__do_sys_reboot+0x11c/0x204) [ 165.375272] [<c0153224>] (__do_sys_reboot) from [<c0100080>] (ret_fast_syscall+0x0/0x28) [ 165.383364] Exception stack(0xd80a5fa8 to 0xd80a5ff0) [ 165.388420] 5fa0: 00406948 00000000 fee1dead 28121969 01234567 73299b00 [ 165.396602] 5fc0: 00406948 00000000 00000000 00000058 be91abc8 00000000 be91ab60 004056f8 [ 165.404781] 5fe0: 00000058 be91aabc b6ed4d45 b6e56746 Signed-off-by: Andreas Kemnade <andreas@kemnade.info> Signed-off-by: Lee Jones <lee.jones@linaro.org>
jaegeuk
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Aug 17, 2020
struct file_ra_state ra.mmap_miss could be accessed concurrently during page faults as noticed by KCSAN, BUG: KCSAN: data-race in filemap_fault / filemap_map_pages write to 0xffff9b1700a2c1b4 of 4 bytes by task 3292 on cpu 30: filemap_fault+0x920/0xfc0 do_sync_mmap_readahead at mm/filemap.c:2384 (inlined by) filemap_fault at mm/filemap.c:2486 __xfs_filemap_fault+0x112/0x3e0 [xfs] xfs_filemap_fault+0x74/0x90 [xfs] __do_fault+0x9e/0x220 do_fault+0x4a0/0x920 __handle_mm_fault+0xc69/0xd00 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 read to 0xffff9b1700a2c1b4 of 4 bytes by task 3313 on cpu 32: filemap_map_pages+0xc2e/0xd80 filemap_map_pages at mm/filemap.c:2625 do_fault+0x3da/0x920 __handle_mm_fault+0xc69/0xd00 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 Reported by Kernel Concurrency Sanitizer on: CPU: 32 PID: 3313 Comm: systemd-udevd Tainted: G W L 5.5.0-next-20200210+ #1 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 ra.mmap_miss is used to contribute the readahead decisions, a data race could be undesirable. Both the read and write is only under non-exclusive mmap_sem, two concurrent writers could even underflow the counter. Fix the underflow by writing to a local variable before committing a final store to ra.mmap_miss given a small inaccuracy of the counter should be acceptable. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Qian Cai <cai@lca.pw> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Marco Elver <elver@google.com> Link: http://lkml.kernel.org/r/20200211030134.1847-1-cai@lca.pw Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jaegeuk
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Aug 17, 2020
Read to lru_add_pvec->nr could be interrupted and then write to the same
variable. The write has local interrupt disabled, but the plain reads
result in data races. However, it is unlikely the compilers could do much
damage here given that lru_add_pvec->nr is a "unsigned char" and there is
an existing compiler barrier. Thus, annotate the reads using the
data_race() macro. The data races were reported by KCSAN,
BUG: KCSAN: data-race in lru_add_drain_cpu / rotate_reclaimable_page
write to 0xffff9291ebcb8a40 of 1 bytes by interrupt on cpu 23:
rotate_reclaimable_page+0x2df/0x490
pagevec_add at include/linux/pagevec.h:81
(inlined by) rotate_reclaimable_page at mm/swap.c:259
end_page_writeback+0x1b5/0x2b0
end_swap_bio_write+0x1d0/0x280
bio_endio+0x297/0x560
dec_pending+0x218/0x430 [dm_mod]
clone_endio+0xe4/0x2c0 [dm_mod]
bio_endio+0x297/0x560
blk_update_request+0x201/0x920
scsi_end_request+0x6b/0x4a0
scsi_io_completion+0xb7/0x7e0
scsi_finish_command+0x1ed/0x2a0
scsi_softirq_done+0x1c9/0x1d0
blk_done_softirq+0x181/0x1d0
__do_softirq+0xd9/0x57c
irq_exit+0xa2/0xc0
do_IRQ+0x8b/0x190
ret_from_intr+0x0/0x42
delay_tsc+0x46/0x80
__const_udelay+0x3c/0x40
__udelay+0x10/0x20
kcsan_setup_watchpoint+0x202/0x3a0
__tsan_read1+0xc2/0x100
lru_add_drain_cpu+0xb8/0x3f0
lru_add_drain+0x25/0x40
shrink_active_list+0xe1/0xc80
shrink_lruvec+0x766/0xb70
shrink_node+0x2d6/0xca0
do_try_to_free_pages+0x1f7/0x9a0
try_to_free_pages+0x252/0x5b0
__alloc_pages_slowpath+0x458/0x1290
__alloc_pages_nodemask+0x3bb/0x450
alloc_pages_vma+0x8a/0x2c0
do_anonymous_page+0x16e/0x6f0
__handle_mm_fault+0xcd5/0xd40
handle_mm_fault+0xfc/0x2f0
do_page_fault+0x263/0x6f9
page_fault+0x34/0x40
read to 0xffff9291ebcb8a40 of 1 bytes by task 37761 on cpu 23:
lru_add_drain_cpu+0xb8/0x3f0
lru_add_drain_cpu at mm/swap.c:602
lru_add_drain+0x25/0x40
shrink_active_list+0xe1/0xc80
shrink_lruvec+0x766/0xb70
shrink_node+0x2d6/0xca0
do_try_to_free_pages+0x1f7/0x9a0
try_to_free_pages+0x252/0x5b0
__alloc_pages_slowpath+0x458/0x1290
__alloc_pages_nodemask+0x3bb/0x450
alloc_pages_vma+0x8a/0x2c0
do_anonymous_page+0x16e/0x6f0
__handle_mm_fault+0xcd5/0xd40
handle_mm_fault+0xfc/0x2f0
do_page_fault+0x263/0x6f9
page_fault+0x34/0x40
2 locks held by oom02/37761:
#0: ffff9281e5928808 (&mm->mmap_sem#2){++++}, at: do_page_fault
#1: ffffffffb3ade380 (fs_reclaim){+.+.}, at: fs_reclaim_acquire.part
irq event stamp: 1949217
trace_hardirqs_on_thunk+0x1a/0x1c
__do_softirq+0x2e7/0x57c
__do_softirq+0x34c/0x57c
irq_exit+0xa2/0xc0
Reported by Kernel Concurrency Sanitizer on:
CPU: 23 PID: 37761 Comm: oom02 Not tainted 5.6.0-rc3-next-20200226+ #6
Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Marco Elver <elver@google.com>
Link: http://lkml.kernel.org/r/20200228044018.1263-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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f2fs:compress: Update isize after compress_write_end, otherwise apendwriting some files would fail when cluster.idx did not add