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authorPeter Lieven <pl@kamp.de>2017-01-19 17:43:50 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2017-01-20 13:22:17 +0100
commite12ed72e5c00dd3375b8bd107200e4d7e950276a (patch)
tree787c5b2e36040215c20caa1cfe84637391889ced /util
parenta049223ab1d71834a311f8c7849cdd68deb9e7b2 (diff)
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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.c8
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);