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| author | Eric Biggers <ebiggers@kernel.org> | 2023-03-16 23:27:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-22 13:26:13 +0100 |
| commit | 8bbd6c83e140a82d558d3567d7d8f743d50e45b5 (patch) | |
| tree | a38f8a5c26e60756649a0d34ca927b361908adf9 | |
| parent | 74f30fa7c92e61e51c5e9ee3df5e5717c5d483ec (diff) | |
| download | linux-8bbd6c83e140a82d558d3567d7d8f743d50e45b5.tar.gz linux-8bbd6c83e140a82d558d3567d7d8f743d50e45b5.tar.bz2 linux-8bbd6c83e140a82d558d3567d7d8f743d50e45b5.zip | |
fs: sysfs_emit_at: Remove PAGE_SIZE alignment check
From: Eric Biggers <ebiggers@google.com>
[No upstream commit because this fixes a bug in a backport.]
Before upstream commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural
alignment for kmalloc(power-of-two)") which went into v5.4, kmalloc did
*not* always guarantee that PAGE_SIZE allocations are PAGE_SIZE-aligned.
Upstream commit 2efc459d06f1 ("sysfs: Add sysfs_emit and sysfs_emit_at
to format sysfs output") added two WARN()s that trigger when PAGE_SIZE
allocations are not PAGE_SIZE-aligned. This was backported to old
kernels that don't guarantee PAGE_SIZE alignment.
Commit 10ddfb495232 ("fs: sysfs_emit: Remove PAGE_SIZE alignment check")
in 4.19.y, and its equivalent in 4.14.y and 4.9.y, tried to fix this
bug. However, only it handled sysfs_emit(), not sysfs_emit_at().
Fix it in sysfs_emit_at() too.
A reproducer is to build the kernel with the following options:
CONFIG_SLUB=y
CONFIG_SLUB_DEBUG=y
CONFIG_SLUB_DEBUG_ON=y
CONFIG_PM=y
CONFIG_SUSPEND=y
CONFIG_PM_WAKELOCKS=y
Then run:
echo foo > /sys/power/wake_lock && cat /sys/power/wake_lock
Fixes: cb1f69d53ac8 ("sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output")
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202303141634.1e64fd76-yujie.liu@intel.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/sysfs/file.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index c41e7f51150f..cef9a469f73a 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -592,7 +592,7 @@ int sysfs_emit_at(char *buf, int at, const char *fmt, ...) va_list args; int len; - if (WARN(!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE, + if (WARN(!buf || at < 0 || at >= PAGE_SIZE, "invalid sysfs_emit_at: buf:%p at:%d\n", buf, at)) return 0; |