fs: allow no_seek_end_llseek to actually seek

The user-visible impact of the issue is for example that without this
patch sensors-detect breaks when trying to seek in /dev/cpu/0/cpuid.

'~0ULL' is a 'unsigned long long' that when converted to a loff_t,
which is signed, gets turned into -1. later in vfs_setpos we have
'if (offset > maxsize)', which makes it always return EINVAL.

Fixes: b25472f9b9 ("new helpers: no_seek_end_llseek{,_size}()")
Signed-off-by: Wouter van Kesteren <woutershep@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Wouter van Kesteren 2016-02-16 22:20:59 +01:00 committed by Al Viro
parent 18558cae02
commit 2feb55f890

View File

@ -17,6 +17,7 @@
#include <linux/splice.h>
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/fs.h>
#include "internal.h"
#include <asm/uaccess.h>
@ -183,7 +184,7 @@ loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
switch (whence) {
case SEEK_SET: case SEEK_CUR:
return generic_file_llseek_size(file, offset, whence,
~0ULL, 0);
OFFSET_MAX, 0);
default:
return -EINVAL;
}