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| author |   Helge Deller <deller@gmx.de> | 2022-03-23 16:06:26 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-23 19:00:34 -0700 |
| commit | 2cd50532ce5c798c029a39234ad7f48a174e15ec (patch) | |
| tree | 1b65c9004acc2a82115824031dd137ef332acfa9 | |
| parent | minix: fix bug when opening a file with O_DIRECT (diff) | |
| download | linux-dev-2cd50532ce5c798c029a39234ad7f48a174e15ec.tar.xz linux-dev-2cd50532ce5c798c029a39234ad7f48a174e15ec.zip | |
fat: use pointer to simple type in put_user()
The put_user(val,ptr) macro wants a pointer to a simple type, but in
fat_ioctl_filldir() the d_name field references an "array of chars". Be
more accurate and explicitly give the pointer to the first character of
the d_name[] array.
I noticed that issue while trying to optimize the parisc put_user()
macro and used an intermediate variable to store the pointer. In that
case I got this error:
In file included from include/linux/uaccess.h:11,
from include/linux/compat.h:17,
from fs/fat/dir.c:18:
fs/fat/dir.c: In function `fat_ioctl_filldir':
fs/fat/dir.c:725:33: error: invalid initializer
725 | if (put_user(0, d2->d_name) || \
| ^~
include/asm/uaccess.h:152:33: note: in definition of macro `__put_user'
152 | __typeof__(ptr) __ptr = ptr; \
| ^~~
fs/fat/dir.c:759:1: note: in expansion of macro `FAT_IOCTL_FILLDIR_FUNC'
759 | FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
Andreas Schwab <schwab@linux-m68k.org> suggested to use
__typeof__(&*(ptr)) __ptr = ptr;
instead. This works, but nevertheless it's probably reasonable to fix
the original caller too.
Link: https://lkml.kernel.org/r/Ygo+A9MREmC1H3kr@p100
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: David Laight <David.Laight@aculab.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/fat/dir.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c index c4a274285858..249825017da7 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -722,7 +722,7 @@ static int func(struct dir_context *ctx, const char *name, int name_len, \ if (name_len >= sizeof(d1->d_name)) \ name_len = sizeof(d1->d_name) - 1; \ \ - if (put_user(0, d2->d_name) || \ + if (put_user(0, &d2->d_name[0]) || \ put_user(0, &d2->d_reclen) || \ copy_to_user(d1->d_name, name, name_len) || \ put_user(0, d1->d_name + name_len) || \ |