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| author | Peter Lieven <pl@kamp.de> | 2017-01-19 17:43:50 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-01-20 13:22:17 +0100 |
| commit | e12ed72e5c00dd3375b8bd107200e4d7e950276a (patch) | |
| tree | 787c5b2e36040215c20caa1cfe84637391889ced /util | |
| parent | a049223ab1d71834a311f8c7849cdd68deb9e7b2 (diff) | |
| download | qemu-e12ed72e5c00dd3375b8bd107200e4d7e950276a.zip qemu-e12ed72e5c00dd3375b8bd107200e4d7e950276a.tar.gz qemu-e12ed72e5c00dd3375b8bd107200e4d7e950276a.tar.bz2 | |
bitmap: assert that start and nr are non negative
commit e1123a3b introduced a data corruption regression
in the iscsi driver because it passed -1 as nr to bitmap_set
and bitmap_clear. Add an assertion to catch such flaws earlier.
Suggested-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Message-Id: <1484844230-24490-1-git-send-email-pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'util')
| -rw-r--r-- | util/bitmap.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/util/bitmap.c b/util/bitmap.c index 43ed011..c1a84ca 100644 --- a/util/bitmap.c +++ b/util/bitmap.c @@ -164,6 +164,8 @@ void bitmap_set(unsigned long *map, long start, long nr) int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + while (nr - bits_to_set >= 0) { *p |= mask_to_set; nr -= bits_to_set; @@ -184,6 +186,8 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + /* First word */ if (nr - bits_to_set > 0) { atomic_or(p, mask_to_set); @@ -221,6 +225,8 @@ void bitmap_clear(unsigned long *map, long start, long nr) int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + assert(start >= 0 && nr >= 0); + while (nr - bits_to_clear >= 0) { *p &= ~mask_to_clear; nr -= bits_to_clear; @@ -243,6 +249,8 @@ bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr) unsigned long dirty = 0; unsigned long old_bits; + assert(start >= 0 && nr >= 0); + /* First word */ if (nr - bits_to_clear > 0) { old_bits = atomic_fetch_and(p, ~mask_to_clear); |