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Revision 56ee254d23c59fd48fb6f192d79858f60cfe2bf6 authored by David Sterba on 27 October 2021, 08:42:27 UTC, committed by David Sterba on 29 October 2021, 11:02:50 UTC 
Revert "btrfs: compression: drop kmap/kunmap from zstd"
 
This reverts commit bbaf9715f3f5b5ff0de71da91fcc34ee9c198ed8.

The kmaps in compression code are still needed and cause crashes on
32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004
with enabled LZO or ZSTD compression.

Example stacktrace with ZSTD on a 32bit ARM machine:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = c4159ed3
  [00000000] *pgd=00000000
  Internal error: Oops: 5 [#1] PREEMPT SMP ARM
  Modules linked in:
  CPU: 0 PID: 210 Comm: kworker/u2:3 Not tainted 5.14.0-rc79+ #12
  Hardware name: Allwinner sun4i/sun5i Families
  Workqueue: btrfs-delalloc btrfs_work_helper
  PC is at mmiocpy+0x48/0x330
  LR is at ZSTD_compressStream_generic+0x15c/0x28c

  (mmiocpy) from [<c0629648>] (ZSTD_compressStream_generic+0x15c/0x28c)
  (ZSTD_compressStream_generic) from [<c06297dc>] (ZSTD_compressStream+0x64/0xa0)
  (ZSTD_compressStream) from [<c049444c>] (zstd_compress_pages+0x170/0x488)
  (zstd_compress_pages) from [<c0496798>] (btrfs_compress_pages+0x124/0x12c)
  (btrfs_compress_pages) from [<c043c068>] (compress_file_range+0x3c0/0x834)
  (compress_file_range) from [<c043c4ec>] (async_cow_start+0x10/0x28)
  (async_cow_start) from [<c0475c3c>] (btrfs_work_helper+0x100/0x230)
  (btrfs_work_helper) from [<c014ef68>] (process_one_work+0x1b4/0x418)
  (process_one_work) from [<c014f210>] (worker_thread+0x44/0x524)
  (worker_thread) from [<c0156aa4>] (kthread+0x180/0x1b0)
  (kthread) from [<c0100150>]

Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839
Signed-off-by: David Sterba <dsterba@suse.com>
1 parent 3a60f65
Raw File
sync-check.sh 
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0

if [ -z "$SRCARCH" ]; then
	echo 'sync-check.sh: error: missing $SRCARCH environment variable' >&2
	exit 1
fi

FILES="include/linux/objtool.h"

if [ "$SRCARCH" = "x86" ]; then
FILES="$FILES
arch/x86/include/asm/nops.h
arch/x86/include/asm/inat_types.h
arch/x86/include/asm/orc_types.h
arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
include/linux/static_call_types.h
"

SYNC_CHECK_FILES='
arch/x86/include/asm/inat.h
arch/x86/include/asm/insn.h
arch/x86/lib/inat.c
arch/x86/lib/insn.c
'
fi

check_2 () {
  file1=$1
  file2=$2

  shift
  shift

  cmd="diff $* $file1 $file2 > /dev/null"

  test -f $file2 && {
    eval $cmd || {
      echo "Warning: Kernel ABI header at '$file1' differs from latest version at '$file2'" >&2
      echo diff -u $file1 $file2
    }
  }
}

check () {
  file=$1

  shift

  check_2 tools/$file $file $*
}

if [ ! -d ../../kernel ] || [ ! -d ../../tools ] || [ ! -d ../objtool ]; then
	exit 0
fi

cd ../..

while read -r file_entry; do
    if [ -z "$file_entry" ]; then
	continue
    fi

    check $file_entry
done <<EOF
$FILES
EOF

if [ "$SRCARCH" = "x86" ]; then
	for i in $SYNC_CHECK_FILES; do
		check $i '-I "^.*\/\*.*__ignore_sync_check__.*\*\/.*$"'
	done
fi
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