| Message ID | 20201209155452.28376-1-olaf@aepfle.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1,1/3] tools: allocate bitmaps in units of unsigned long | expand |
On Wed, Dec 09, 2020 at 04:54:49PM +0100, Olaf Hering wrote: > Allocate enough memory so that the returned pointer can be safely > accessed as an array of unsigned long. > > The actual bitmap size in units of bytes, as returned by bitmap_size, > remains unchanged. > > Signed-off-by: Olaf Hering <olaf@aepfle.de> Acked-by: Wei Liu <wl@xen.org> I can see where you're coming from. This (internal) API's returned pointer is being assigned to unsigned long *. > --- > tools/libs/ctrl/xc_bitops.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h > index 3d3a09772a..d6c5ea5138 100644 > --- a/tools/libs/ctrl/xc_bitops.h > +++ b/tools/libs/ctrl/xc_bitops.h > @@ -21,7 +21,10 @@ static inline unsigned long bitmap_size(unsigned long nr_bits) > > static inline void *bitmap_alloc(unsigned long nr_bits) > { > - return calloc(1, bitmap_size(nr_bits)); > + unsigned long longs; > + > + longs = (nr_bits + BITS_PER_LONG - 1) / BITS_PER_LONG; > + return calloc(longs, sizeof(unsigned long)); > } > > static inline void bitmap_set(void *addr, unsigned long nr_bits)
diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h index 3d3a09772a..d6c5ea5138 100644 --- a/tools/libs/ctrl/xc_bitops.h +++ b/tools/libs/ctrl/xc_bitops.h @@ -21,7 +21,10 @@ static inline unsigned long bitmap_size(unsigned long nr_bits) static inline void *bitmap_alloc(unsigned long nr_bits) { - return calloc(1, bitmap_size(nr_bits)); + unsigned long longs; + + longs = (nr_bits + BITS_PER_LONG - 1) / BITS_PER_LONG; + return calloc(longs, sizeof(unsigned long)); } static inline void bitmap_set(void *addr, unsigned long nr_bits)
Allocate enough memory so that the returned pointer can be safely accessed as an array of unsigned long. The actual bitmap size in units of bytes, as returned by bitmap_size, remains unchanged. Signed-off-by: Olaf Hering <olaf@aepfle.de> --- tools/libs/ctrl/xc_bitops.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)