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  1. Oct 03, 2020
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    • Pali Rohár's avatar
    • Ard Biesheuvel's avatar
      arm64: permit ACPI core to map kernel memory used for table overrides · a509a66a
      Ard Biesheuvel authored
      Jonathan reports that the strict policy for memory mapped by the
      ACPI core breaks the use case of passing ACPI table overrides via
      initramfs. This is due to the fact that the memory type used for
      loading the initramfs in memory is not recognized as a memory type
      that is typically used by firmware to pass firmware tables.
      
      Since the purpose of the strict policy is to ensure that no AML or
      other ACPI code can manipulate any memory that is used by the kernel
      to keep its internal state or the state of user tasks, we can relax
      the permission check, and allow mappings of memory that is reserved
      and marked as NOMAP via memblock, and therefore not covered by the
      linear mapping to begin with.
      
      Fixes: 1583052d ("arm64/acpi: disallow AML memory opregions to access kernel memory")
      Fixes: 325f5585
      
       ("arm64/acpi: disallow writeable AML opregion mapping for EFI code regions")
      Reported-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
      Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
      Tested-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Sudeep Holla <sudeep.holla@arm.com>
      Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
      Link: https://lore.kernel.org/r/20200929132522.18067-1-ardb@kernel.org
      
      
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      a509a66a
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux · 60e72093
      Linus Torvalds authored
      Pull clk fixes from Stephen Boyd:
       "Another batch of clk driver fixes:
      
         - Make sure DRAM and ChipID region doesn't get disabled on Exynos
      
         - Fix a SATA failure on Tegra
      
         - Fix the emac_ptp clk divider on stratix10"
      
      * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
        clk: socfpga: stratix10: fix the divider for the emac_ptp_free_clk
        clk: samsung: exynos4: mark 'chipid' clock as CLK_IGNORE_UNUSED
        clk: tegra: Fix missing prototype for tegra210_clk_register_emc()
        clk: tegra: Always program PLL_E when enabled
        clk: tegra: Capitalization fixes
        clk: samsung: Keep top BPLL mux on Exynos542x enabled
      60e72093
    • Anup Patel's avatar
      RISC-V: Check clint_time_val before use · aa988760
      Anup Patel authored
      The NoMMU kernel is broken for QEMU virt machine from Linux-5.9-rc6
      because clint_time_val is used even before CLINT driver is probed
      at following places:
      1. rand_initialize() calls get_cycles() which in-turn uses
         clint_time_val
      2. boot_init_stack_canary() calls get_cycles() which in-turn
         uses clint_time_val
      
      The issue#1 (above) is fixed by providing custom random_get_entropy()
      for RISC-V NoMMU kernel. For issue#2 (above), we remove dependency of
      boot_init_stack_canary() on get_cycles() and this is aligned with the
      boot_init_stack_canary() implementations of ARM, ARM64 and MIPS kernel.
      
      Fixes: d5be89a8
      
       ("RISC-V: Resurrect the MMIO timer implementation for M-mode systems")
      Signed-off-by: default avatarAnup Patel <anup.patel@wdc.com>
      Tested-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
      Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
      aa988760
    • Filipe Manana's avatar
      btrfs: fix filesystem corruption after a device replace · 4c8f3532
      Filipe Manana authored
      We use a device's allocation state tree to track ranges in a device used
      for allocated chunks, and we set ranges in this tree when allocating a new
      chunk. However after a device replace operation, we were not setting the
      allocated ranges in the new device's allocation state tree, so that tree
      is empty after a device replace.
      
      This means that a fitrim operation after a device replace will trim the
      device ranges that have allocated chunks and extents, as we trim every
      range for which there is not a range marked in the device's allocation
      state tree. It is also important during chunk allocation, since the
      device's allocation state is used to determine if a range is already
      allocated when allocating a new chunk.
      
      This is trivial to reproduce and the following script triggers the bug:
      
        $ cat reproducer.sh
        #!/bin/bash
      
        DEV1="/dev/sdg"
        DEV2="/dev/sdh"
        DEV3="/dev/sdi"
      
        wipefs -a $DEV1 $DEV2 $DEV3 &> /dev/null
      
        # Create a raid1 test fs on 2 devices.
        mkfs.btrfs -f -m raid1 -d raid1 $DEV1 $DEV2 > /dev/null
        mount $DEV1 /mnt/btrfs
      
        xfs_io -f -c "pwrite -S 0xab 0 10M" /mnt/btrfs/foo
      
        echo "Starting to replace $DEV1 with $DEV3"
        btrfs replace start -B $DEV1 $DEV3 /mnt/btrfs
        echo
      
        echo "Running fstrim"
        fstrim /mnt/btrfs
        echo
      
        echo "Unmounting filesystem"
        umount /mnt/btrfs
      
        echo "Mounting filesystem in degraded mode using $DEV3 only"
        wipefs -a $DEV1 $DEV2 &> /dev/null
        mount -o degraded $DEV3 /mnt/btrfs
        if [ $? -ne 0 ]; then
                dmesg | tail
                echo
                echo "Failed to mount in degraded mode"
                exit 1
        fi
      
        echo
        echo "File foo data (expected all bytes = 0xab):"
        od -A d -t x1 /mnt/btrfs/foo
      
        umount /mnt/btrfs
      
      When running the reproducer:
      
        $ ./replace-test.sh
        wrote 10485760/10485760 bytes at offset 0
        10 MiB, 2560 ops; 0.0901 sec (110.877 MiB/sec and 28384.5216 ops/sec)
        Starting to replace /dev/sdg with /dev/sdi
      
        Running fstrim
      
        Unmounting filesystem
        Mounting filesystem in degraded mode using /dev/sdi only
        mount: /mnt/btrfs: wrong fs type, bad option, bad superblock on /dev/sdi, missing codepage or helper program, or other error.
        [19581.748641] BTRFS info (device sdg): dev_replace from /dev/sdg (devid 1) to /dev/sdi started
        [19581.803842] BTRFS info (device sdg): dev_replace from /dev/sdg (devid 1) to /dev/sdi finished
        [19582.208293] BTRFS info (device sdi): allowing degraded mounts
        [19582.208298] BTRFS info (device sdi): disk space caching is enabled
        [19582.208301] BTRFS info (device sdi): has skinny extents
        [19582.212853] BTRFS warning (device sdi): devid 2 uuid 1f731f47-e1bb-4f00-bfbb-9e5a0cb4ba9f is missing
        [19582.213904] btree_readpage_end_io_hook: 25839 callbacks suppressed
        [19582.213907] BTRFS error (device sdi): bad tree block start, want 30490624 have 0
        [19582.214780] BTRFS warning (device sdi): failed to read root (objectid=7): -5
        [19582.231576] BTRFS error (device sdi): open_ctree failed
      
        Failed to mount in degraded mode
      
      So fix by setting all allocated ranges in the replace target device when
      the replace operation is finishing, when we are holding the chunk mutex
      and we can not race with new chunk allocations.
      
      A test case for fstests follows soon.
      
      Fixes: 1c11b63e
      
       ("btrfs: replace pending/pinned chunks lists with io tree")
      CC: stable@vger.kernel.org # 5.2+
      Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
      Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      4c8f3532
    • Josef Bacik's avatar
      btrfs: move btrfs_rm_dev_replace_free_srcdev outside of all locks · a466c85e
      Josef Bacik authored
      When closing and freeing the source device we could end up doing our
      final blkdev_put() on the bdev, which will grab the bd_mutex.  As such
      we want to be holding as few locks as possible, so move this call
      outside of the dev_replace->lock_finishing_cancel_unmount lock.  Since
      we're modifying the fs_devices we need to make sure we're holding the
      uuid_mutex here, so take that as well.
      
      There's a report from syzbot probably hitting one of the cases where
      the bd_mutex and device_list_mutex are taken in the wrong order, however
      it's not with device replace, like this patch fixes. As there's no
      reproducer available so far, we can't verify the fix.
      
      https://lore.kernel.org/lkml/000000000000fc04d105afcf86d7@google.com/
      dashboard link: https://syzkaller.appspot.com/bug?extid=84a0634dc5d21d488419
      
      
      
        WARNING: possible circular locking dependency detected
        5.9.0-rc5-syzkaller #0 Not tainted
        ------------------------------------------------------
        syz-executor.0/6878 is trying to acquire lock:
        ffff88804c17d780 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_put+0x30/0x520 fs/block_dev.c:1804
      
        but task is already holding lock:
        ffff8880908cfce0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: close_fs_devices.part.0+0x2e/0x800 fs/btrfs/volumes.c:1159
      
        which lock already depends on the new lock.
      
        the existing dependency chain (in reverse order) is:
      
        -> #4 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
      	 __mutex_lock_common kernel/locking/mutex.c:956 [inline]
      	 __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
      	 btrfs_finish_chunk_alloc+0x281/0xf90 fs/btrfs/volumes.c:5255
      	 btrfs_create_pending_block_groups+0x2f3/0x700 fs/btrfs/block-group.c:2109
      	 __btrfs_end_transaction+0xf5/0x690 fs/btrfs/transaction.c:916
      	 find_free_extent_update_loop fs/btrfs/extent-tree.c:3807 [inline]
      	 find_free_extent+0x23b7/0x2e60 fs/btrfs/extent-tree.c:4127
      	 btrfs_reserve_extent+0x166/0x460 fs/btrfs/extent-tree.c:4206
      	 cow_file_range+0x3de/0x9b0 fs/btrfs/inode.c:1063
      	 btrfs_run_delalloc_range+0x2cf/0x1410 fs/btrfs/inode.c:1838
      	 writepage_delalloc+0x150/0x460 fs/btrfs/extent_io.c:3439
      	 __extent_writepage+0x441/0xd00 fs/btrfs/extent_io.c:3653
      	 extent_write_cache_pages.constprop.0+0x69d/0x1040 fs/btrfs/extent_io.c:4249
      	 extent_writepages+0xcd/0x2b0 fs/btrfs/extent_io.c:4370
      	 do_writepages+0xec/0x290 mm/page-writeback.c:2352
      	 __writeback_single_inode+0x125/0x1400 fs/fs-writeback.c:1461
      	 writeback_sb_inodes+0x53d/0xf40 fs/fs-writeback.c:1721
      	 wb_writeback+0x2ad/0xd40 fs/fs-writeback.c:1894
      	 wb_do_writeback fs/fs-writeback.c:2039 [inline]
      	 wb_workfn+0x2dc/0x13e0 fs/fs-writeback.c:2080
      	 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
      	 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
      	 kthread+0x3b5/0x4a0 kernel/kthread.c:292
      	 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
      
        -> #3 (sb_internal#2){.+.+}-{0:0}:
      	 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
      	 __sb_start_write+0x234/0x470 fs/super.c:1672
      	 sb_start_intwrite include/linux/fs.h:1690 [inline]
      	 start_transaction+0xbe7/0x1170 fs/btrfs/transaction.c:624
      	 find_free_extent_update_loop fs/btrfs/extent-tree.c:3789 [inline]
      	 find_free_extent+0x25e1/0x2e60 fs/btrfs/extent-tree.c:4127
      	 btrfs_reserve_extent+0x166/0x460 fs/btrfs/extent-tree.c:4206
      	 cow_file_range+0x3de/0x9b0 fs/btrfs/inode.c:1063
      	 btrfs_run_delalloc_range+0x2cf/0x1410 fs/btrfs/inode.c:1838
      	 writepage_delalloc+0x150/0x460 fs/btrfs/extent_io.c:3439
      	 __extent_writepage+0x441/0xd00 fs/btrfs/extent_io.c:3653
      	 extent_write_cache_pages.constprop.0+0x69d/0x1040 fs/btrfs/extent_io.c:4249
      	 extent_writepages+0xcd/0x2b0 fs/btrfs/extent_io.c:4370
      	 do_writepages+0xec/0x290 mm/page-writeback.c:2352
      	 __writeback_single_inode+0x125/0x1400 fs/fs-writeback.c:1461
      	 writeback_sb_inodes+0x53d/0xf40 fs/fs-writeback.c:1721
      	 wb_writeback+0x2ad/0xd40 fs/fs-writeback.c:1894
      	 wb_do_writeback fs/fs-writeback.c:2039 [inline]
      	 wb_workfn+0x2dc/0x13e0 fs/fs-writeback.c:2080
      	 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
      	 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
      	 kthread+0x3b5/0x4a0 kernel/kthread.c:292
      	 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
      
        -> #2 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}:
      	 __flush_work+0x60e/0xac0 kernel/workqueue.c:3041
      	 wb_shutdown+0x180/0x220 mm/backing-dev.c:355
      	 bdi_unregister+0x174/0x590 mm/backing-dev.c:872
      	 del_gendisk+0x820/0xa10 block/genhd.c:933
      	 loop_remove drivers/block/loop.c:2192 [inline]
      	 loop_control_ioctl drivers/block/loop.c:2291 [inline]
      	 loop_control_ioctl+0x3b1/0x480 drivers/block/loop.c:2257
      	 vfs_ioctl fs/ioctl.c:48 [inline]
      	 __do_sys_ioctl fs/ioctl.c:753 [inline]
      	 __se_sys_ioctl fs/ioctl.c:739 [inline]
      	 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
      	 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
      	 entry_SYSCALL_64_after_hwframe+0x44/0xa9
      
        -> #1 (loop_ctl_mutex){+.+.}-{3:3}:
      	 __mutex_lock_common kernel/locking/mutex.c:956 [inline]
      	 __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
      	 lo_open+0x19/0xd0 drivers/block/loop.c:1893
      	 __blkdev_get+0x759/0x1aa0 fs/block_dev.c:1507
      	 blkdev_get fs/block_dev.c:1639 [inline]
      	 blkdev_open+0x227/0x300 fs/block_dev.c:1753
      	 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
      	 do_open fs/namei.c:3251 [inline]
      	 path_openat+0x1b9a/0x2730 fs/namei.c:3368
      	 do_filp_open+0x17e/0x3c0 fs/namei.c:3395
      	 do_sys_openat2+0x16d/0x420 fs/open.c:1168
      	 do_sys_open fs/open.c:1184 [inline]
      	 __do_sys_open fs/open.c:1192 [inline]
      	 __se_sys_open fs/open.c:1188 [inline]
      	 __x64_sys_open+0x119/0x1c0 fs/open.c:1188
      	 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
      	 entry_SYSCALL_64_after_hwframe+0x44/0xa9
      
        -> #0 (&bdev->bd_mutex){+.+.}-{3:3}:
      	 check_prev_add kernel/locking/lockdep.c:2496 [inline]
      	 check_prevs_add kernel/locking/lockdep.c:2601 [inline]
      	 validate_chain kernel/locking/lockdep.c:3218 [inline]
      	 __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4426
      	 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
      	 __mutex_lock_common kernel/locking/mutex.c:956 [inline]
      	 __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
      	 blkdev_put+0x30/0x520 fs/block_dev.c:1804
      	 btrfs_close_bdev fs/btrfs/volumes.c:1117 [inline]
      	 btrfs_close_bdev fs/btrfs/volumes.c:1107 [inline]
      	 btrfs_close_one_device fs/btrfs/volumes.c:1133 [inline]
      	 close_fs_devices.part.0+0x1a4/0x800 fs/btrfs/volumes.c:1161
      	 close_fs_devices fs/btrfs/volumes.c:1193 [inline]
      	 btrfs_close_devices+0x95/0x1f0 fs/btrfs/volumes.c:1179
      	 close_ctree+0x688/0x6cb fs/btrfs/disk-io.c:4149
      	 generic_shutdown_super+0x144/0x370 fs/super.c:464
      	 kill_anon_super+0x36/0x60 fs/super.c:1108
      	 btrfs_kill_super+0x38/0x50 fs/btrfs/super.c:2265
      	 deactivate_locked_super+0x94/0x160 fs/super.c:335
      	 deactivate_super+0xad/0xd0 fs/super.c:366
      	 cleanup_mnt+0x3a3/0x530 fs/namespace.c:1118
      	 task_work_run+0xdd/0x190 kernel/task_work.c:141
      	 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
      	 exit_to_user_mode_loop kernel/entry/common.c:163 [inline]
      	 exit_to_user_mode_prepare+0x1e1/0x200 kernel/entry/common.c:190
      	 syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:265
      	 entry_SYSCALL_64_after_hwframe+0x44/0xa9
      
        other info that might help us debug this:
      
        Chain exists of:
          &bdev->bd_mutex --> sb_internal#2 --> &fs_devs->device_list_mutex
      
         Possible unsafe locking scenario:
      
      	 CPU0                    CPU1
      	 ----                    ----
          lock(&fs_devs->device_list_mutex);
      				 lock(sb_internal#2);
      				 lock(&fs_devs->device_list_mutex);
          lock(&bdev->bd_mutex);
      
         *** DEADLOCK ***
      
        3 locks held by syz-executor.0/6878:
         #0: ffff88809070c0e0 (&type->s_umount_key#70){++++}-{3:3}, at: deactivate_super+0xa5/0xd0 fs/super.c:365
         #1: ffffffff8a5b37a8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_close_devices+0x23/0x1f0 fs/btrfs/volumes.c:1178
         #2: ffff8880908cfce0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: close_fs_devices.part.0+0x2e/0x800 fs/btrfs/volumes.c:1159
      
        stack backtrace:
        CPU: 0 PID: 6878 Comm: syz-executor.0 Not tainted 5.9.0-rc5-syzkaller #0
        Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
        Call Trace:
         __dump_stack lib/dump_stack.c:77 [inline]
         dump_stack+0x198/0x1fd lib/dump_stack.c:118
         check_noncircular+0x324/0x3e0 kernel/locking/lockdep.c:1827
         check_prev_add kernel/locking/lockdep.c:2496 [inline]
         check_prevs_add kernel/locking/lockdep.c:2601 [inline]
         validate_chain kernel/locking/lockdep.c:3218 [inline]
         __lock_acquire+0x2a96/0x5780 kernel/locking/lockdep.c:4426
         lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
         __mutex_lock_common kernel/locking/mutex.c:956 [inline]
         __mutex_lock+0x134/0x10e0 kernel/locking/mutex.c:1103
         blkdev_put+0x30/0x520 fs/block_dev.c:1804
         btrfs_close_bdev fs/btrfs/volumes.c:1117 [inline]
         btrfs_close_bdev fs/btrfs/volumes.c:1107 [inline]
         btrfs_close_one_device fs/btrfs/volumes.c:1133 [inline]
         close_fs_devices.part.0+0x1a4/0x800 fs/btrfs/volumes.c:1161
         close_fs_devices fs/btrfs/volumes.c:1193 [inline]
         btrfs_close_devices+0x95/0x1f0 fs/btrfs/volumes.c:1179
         close_ctree+0x688/0x6cb fs/btrfs/disk-io.c:4149
         generic_shutdown_super+0x144/0x370 fs/super.c:464
         kill_anon_super+0x36/0x60 fs/super.c:1108
         btrfs_kill_super+0x38/0x50 fs/btrfs/super.c:2265
         deactivate_locked_super+0x94/0x160 fs/super.c:335
         deactivate_super+0xad/0xd0 fs/super.c:366
         cleanup_mnt+0x3a3/0x530 fs/namespace.c:1118
         task_work_run+0xdd/0x190 kernel/task_work.c:141
         tracehook_notify_resume include/linux/tracehook.h:188 [inline]
         exit_to_user_mode_loop kernel/entry/common.c:163 [inline]
         exit_to_user_mode_prepare+0x1e1/0x200 kernel/entry/common.c:190
         syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:265
         entry_SYSCALL_64_after_hwframe+0x44/0xa9
        RIP: 0033:0x460027
        RSP: 002b:00007fff59216328 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
        RAX: 0000000000000000 RBX: 0000000000076035 RCX: 0000000000460027
        RDX: 0000000000403188 RSI: 0000000000000002 RDI: 00007fff592163d0
        RBP: 0000000000000333 R08: 0000000000000000 R09: 000000000000000b
        R10: 0000000000000005 R11: 0000000000000246 R12: 00007fff59217460
        R13: 0000000002df2a60 R14: 0000000000000000 R15: 00007fff59217460
      
      Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
      [ add syzbot reference ]
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      a466c85e
    • Ulf Hansson's avatar
      ARM: imx6q: Fixup RCU usage for cpuidle · 1a67b926
      Ulf Hansson authored
      The commit eb1f0023
      
       ("lockdep,trace: Expose tracepoints"), started to
      expose us for tracepoints. For imx6q cpuidle, this leads to an RCU splat
      according to below.
      
      [6.870684] [<c0db7690>] (_raw_spin_lock) from [<c011f6a4>] (imx6q_enter_wait+0x18/0x9c)
      [6.878846] [<c011f6a4>] (imx6q_enter_wait) from [<c09abfb0>] (cpuidle_enter_state+0x168/0x5e4)
      
      To fix the problem, let's assign the corresponding idlestate->flags the
      CPUIDLE_FLAG_RCU_IDLE bit, which enables us to call rcu_idle_enter|exit()
      at the proper point.
      
      Reported-by: default avatarDong Aisheng <aisheng.dong@nxp.com>
      Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      1a67b926