Helge Deller <deller@xxxxxx> writes: > 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@xxxxxxxxxxxxxx> suggested to use > __typeof__(&*(ptr)) __ptr = ptr; > instead. This works, but nevertheless it's probably reasonable to > fix the original caller too. > > Signed-off-by: Helge Deller <deller@xxxxxx> Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> > __ > v2: Adjusted the description with input from David Laight > <David.Laight@xxxxxxxxxx> and Andreas Schwab <schwab@xxxxxxxxxxxxxx>. > > 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) || \ -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
