Eric Lee / linux-smarc-t335x-v3.2

Download as
Browse Code ยป

Commit dcefafb6ac90ece8d68a6c203105f3d313e52da4

Authored by Wu Fengguang
Committed by Linus Torvalds
1 parent 2cb9a75d13
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

/dev/mem: dont allow seek to last page 

So as to return a uniform error -EOVERFLOW instead of a random one:

# kmem-seek 0xfffffffffffffff0
seek /dev/kmem: Device or resource busy
# kmem-seek 0xfffffffffffffff1
seek /dev/kmem: Block device required

Suggested by OGAWA Hirofumi.

Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 13 additions and 6 deletions Side-by-side Diff

... ... @@ -708,13 +708,20 @@
708 708  
709 709 mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
710 710 switch (orig) {
711   - case 0:
  711 + case SEEK_CUR:
  712 + offset += file->f_pos;
  713 + if ((unsigned long long)offset <
  714 + (unsigned long long)file->f_pos) {
  715 + ret = -EOVERFLOW;
  716 + break;
  717 + }
  718 + case SEEK_SET:
  719 + /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
  720 + if ((unsigned long long)offset >= ~0xFFFULL) {
  721 + ret = -EOVERFLOW;
  722 + break;
  723 + }
712 724 file->f_pos = offset;
713   - ret = file->f_pos;
714   - force_successful_syscall_return();
715   - break;
716   - case 1:
717   - file->f_pos += offset;
718 725 ret = file->f_pos;
719 726 force_successful_syscall_return();
720 727 break;