5.10-stable review patch. If anyone has any objections, please let me know.
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From: David Laight David.Laight@ACULAB.COM
[ Upstream commit 495bba17cdf95e9703af1b8ef773c55ef0dfe703 ]
Always pass a 'type' through to __clamp_once(), pass '__auto_type' from clamp() itself.
The expansion of __types_ok3() is reasonable so it isn't worth the added complexity of avoiding it when a fixed type is used for all three values.
Link: https://lkml.kernel.org/r/8f69f4deac014f558bab186444bac2e8@AcuMS.aculab.com Signed-off-by: David Laight david.laight@aculab.com Cc: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: Arnd Bergmann arnd@kernel.org Cc: Christoph Hellwig hch@infradead.org Cc: Dan Carpenter dan.carpenter@linaro.org Cc: Jason A. Donenfeld Jason@zx2c4.com Cc: Jens Axboe axboe@kernel.dk Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com Cc: Mateusz Guzik mjguzik@gmail.com Cc: Matthew Wilcox willy@infradead.org Cc: Pedro Falcato pedro.falcato@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Eliav Farber farbere@amazon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/minmax.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
--- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -183,29 +183,29 @@ #define __clamp(val, lo, hi) \ ((val) >= (hi) ? (hi) : ((val) <= (lo) ? (lo) : (val)))
-#define __clamp_once(val, lo, hi, uval, ulo, uhi) ({ \ - __auto_type uval = (val); \ - __auto_type ulo = (lo); \ - __auto_type uhi = (hi); \ +#define __clamp_once(type, val, lo, hi, uval, ulo, uhi) ({ \ + type uval = (val); \ + type ulo = (lo); \ + type uhi = (hi); \ BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ "clamp() low limit " #lo " greater than high limit " #hi); \ BUILD_BUG_ON_MSG(!__types_ok3(uval, ulo, uhi), \ "clamp("#val", "#lo", "#hi") signedness error"); \ __clamp(uval, ulo, uhi); })
-#define __careful_clamp(val, lo, hi) \ - __clamp_once(val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) +#define __careful_clamp(type, val, lo, hi) \ + __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_))
/** - * clamp - return a value clamped to a given range with strict typechecking + * clamp - return a value clamped to a given range with typechecking * @val: current value * @lo: lowest allowable value * @hi: highest allowable value * - * This macro does strict typechecking of @lo/@hi to make sure they are of the - * same type as @val. See the unnecessary pointer comparisons. + * This macro checks @val/@lo/@hi to make sure they have compatible + * signedness. */ -#define clamp(val, lo, hi) __careful_clamp(val, lo, hi) +#define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi)
/** * clamp_t - return a value clamped to a given range using a given type @@ -217,7 +217,7 @@ * This macro does no typechecking and uses temporary variables of type * @type to make all the comparisons. */ -#define clamp_t(type, val, lo, hi) __careful_clamp((type)(val), (type)(lo), (type)(hi)) +#define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi)
/** * clamp_val - return a value clamped to a given range using val's type @@ -230,7 +230,7 @@ * type and @lo and @hi are literals that will otherwise be assigned a signed * integer type. */ -#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) +#define clamp_val(val, lo, hi) __careful_clamp(typeof(val), val, lo, hi)
/* * Do not check the array parameter using __must_be_array().