The patch titled
Subject: lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()
has been added to the -mm tree. Its filename is
bitmap-fix-undefined-shift-in-__bitmap_shift_leftright.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/bitmap-fix-undefined-shift-in-__bitmap_shift_leftright.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/bitmap-fix-undefined-shift-in-__bitmap_shift_leftright.patch
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------------------------------------------------------
From: Jan Kara <[email protected]>
Subject: lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()
If __bitmap_shift_left() or __bitmap_shift_right() are asked to shift by a
multiple of BITS_PER_LONG, they will try to shift a long value by
BITS_PER_LONG bits which is undefined. Change the functions to avoid the
undefined shift.
Coverity id: 1192175
Coverity id: 1192174
Signed-off-by: Jan Kara <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
lib/bitmap.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff -puN lib/bitmap.c~bitmap-fix-undefined-shift-in-__bitmap_shift_leftright
lib/bitmap.c
--- a/lib/bitmap.c~bitmap-fix-undefined-shift-in-__bitmap_shift_leftright
+++ a/lib/bitmap.c
@@ -131,7 +131,9 @@ void __bitmap_shift_right(unsigned long
lower = src[off + k];
if (left && off + k == lim - 1)
lower &= mask;
- dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
+ dst[k] = lower >> rem;
+ if (rem)
+ dst[k] |= upper << (BITS_PER_LONG - rem);
if (left && k == lim - 1)
dst[k] &= mask;
}
@@ -172,7 +174,9 @@ void __bitmap_shift_left(unsigned long *
upper = src[k];
if (left && k == lim - 1)
upper &= (1UL << left) - 1;
- dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
+ dst[k + off] = upper << rem;
+ if (rem)
+ dst[k + off] |= lower >> (BITS_PER_LONG - rem);
if (left && k + off == lim - 1)
dst[k + off] &= (1UL << left) - 1;
}
_
Patches currently in -mm which might be from [email protected] are
origin.patch
bitmap-fix-undefined-shift-in-__bitmap_shift_leftright.patch
fallocate-create-fan_modify-and-in_modify-events.patch
fs-ext4-fsyncc-generic_file_fsync-call-based-on-barrier-flag.patch
ocfs2-fix-xattr-check-in-ocfs2_get_xattr_nolock.patch
fs-mpagec-forgotten-write_sync-in-case-of-data-integrity-write.patch
mm-add-strictlimit-knob-v2.patch
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