John Snow <js...@redhat.com> writes: > From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > > Functions to serialize / deserialize(restore) HBitmap. HBitmap should be > saved to linear sequence of bits independently of endianness and bitmap > array element (unsigned long) size. Therefore Little Endian is chosen. > > These functions are appropriate for dirty bitmap migration, restoring > the bitmap in several steps is available. To save performance, every > step writes only the last level of the bitmap. All other levels are > restored by hbitmap_deserialize_finish() as a last step of restoring. > So, HBitmap is inconsistent while restoring. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > [Fix left shift operand to 1UL; add "finish" parameter. - Fam] > Signed-off-by: Fam Zheng <f...@redhat.com> > > Signed-off-by: John Snow <js...@redhat.com> [...] > diff --git a/util/hbitmap.c b/util/hbitmap.c > index f303975..5d1a21c 100644 > --- a/util/hbitmap.c > +++ b/util/hbitmap.c > @@ -397,6 +397,143 @@ bool hbitmap_get(const HBitmap *hb, uint64_t item) > return (hb->levels[HBITMAP_LEVELS - 1][pos >> BITS_PER_LEVEL] & bit) != > 0; > } > > +uint64_t hbitmap_serialization_granularity(const HBitmap *hb) > +{ > + /* Require at least 64 bit granularity to be safe on both 64 bit and 32 > bit > + * hosts. */ > + return 64 << hb->granularity; > +}
Coverity reports: *** CID 1365378: Integer handling issues (OVERFLOW_BEFORE_WIDEN) /util/hbitmap.c: 404 in hbitmap_serialization_granularity() 398 } 399 400 uint64_t hbitmap_serialization_granularity(const HBitmap *hb) 401 { 402 /* Require at least 64 bit granularity to be safe on both 64 bit and 32 bit 403 * hosts. */ >>> CID 1365378: Integer handling issues (OVERFLOW_BEFORE_WIDEN) >>> Potentially overflowing expression "0x40 << hb->granularity" with type "int" (32 bits, signed) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "uint64_t" (64 bits, unsigned). 404 return 64 << hb->granularity; 405 } 406 407 /* Start should be aligned to serialization granularity, chunk size should be 408 * aligned to serialization granularity too, except for last chunk. 409 */ Use (uint64_t)64 << hb->granularity for an unsigned 64 bit shift. [...]