Commit 4b44cbb2 authored by Kees Cook's avatar Kees Cook
Browse files

overflow: Make sure size helpers are always inlined 



With kmalloc_obj() performing implicit size calculations, the embedded
size_mul() calls, while marked inline, were not always being inlined.
I noticed a couple places where allocations were making a call out for
things that would otherwise be compile-time calculated. Force the
compilers to always inline these calculations.

Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://patch.msgid.link/20260224232451.work.614-kees@kernel.org


Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent f709859f

include/linux/overflow.h

+4 −4
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ 
 * both the type-agnostic benefits of the macros while also being able to

 * enforce that the return value is, in fact, checked.

 */

static inline bool __must_check __must_check_overflow(bool overflow)

static __always_inline bool __must_check __must_check_overflow(bool overflow)

{

	return unlikely(overflow);

}
@@ -327,7 +327,7 @@ static inline bool __must_check __must_check_overflow(bool overflow) 
 * with any overflow causing the return value to be SIZE_MAX. The

 * lvalue must be size_t to avoid implicit type conversion.

 */

static inline size_t __must_check size_mul(size_t factor1, size_t factor2)

static __always_inline size_t __must_check size_mul(size_t factor1, size_t factor2)

{

	size_t bytes;
@@ -346,7 +346,7 @@ static inline size_t __must_check size_mul(size_t factor1, size_t factor2) 
 * with any overflow causing the return value to be SIZE_MAX. The

 * lvalue must be size_t to avoid implicit type conversion.

 */

static inline size_t __must_check size_add(size_t addend1, size_t addend2)

static __always_inline size_t __must_check size_add(size_t addend1, size_t addend2)

{

	size_t bytes;
@@ -367,7 +367,7 @@ static inline size_t __must_check size_add(size_t addend1, size_t addend2) 
 * argument may be SIZE_MAX (or the result with be forced to SIZE_MAX).

 * The lvalue must be size_t to avoid implicit type conversion.

 */

static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)

static __always_inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)

{

	size_t bytes;