diff options
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.h | 8 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_color_mgmt.c | 4 | ||||
| -rw-r--r-- | include/linux/kernel.h | 71 |
3 files changed, 47 insertions, 36 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index d5c6a2e952b3..f6e1dbe212a7 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -62,10 +62,10 @@ enum tis_defaults { /* Some timeout values are needed before it is known whether the chip is * TPM 1.0 or TPM 2.0. */ -#define TIS_TIMEOUT_A_MAX max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_A) -#define TIS_TIMEOUT_B_MAX max(TIS_LONG_TIMEOUT, TPM2_TIMEOUT_B) -#define TIS_TIMEOUT_C_MAX max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_C) -#define TIS_TIMEOUT_D_MAX max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_D) +#define TIS_TIMEOUT_A_MAX max_t(int, TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_A) +#define TIS_TIMEOUT_B_MAX max_t(int, TIS_LONG_TIMEOUT, TPM2_TIMEOUT_B) +#define TIS_TIMEOUT_C_MAX max_t(int, TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_C) +#define TIS_TIMEOUT_D_MAX max_t(int, TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_D) #define TPM_ACCESS(l) (0x0000 | ((l) << 12)) #define TPM_INT_ENABLE(l) (0x0008 | ((l) << 12)) diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index 4ff064623836..b97e2de2c029 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -417,8 +417,8 @@ int drm_plane_create_color_properties(struct drm_plane *plane, { struct drm_device *dev = plane->dev; struct drm_property *prop; - struct drm_prop_enum_list enum_list[max(DRM_COLOR_ENCODING_MAX, - DRM_COLOR_RANGE_MAX)]; + struct drm_prop_enum_list enum_list[max_t(int, DRM_COLOR_ENCODING_MAX, + DRM_COLOR_RANGE_MAX)]; int i, len; if (WARN_ON(supported_encodings == 0 || diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3cbf3cfff4f0..4ae1dfd9bf05 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -792,41 +792,58 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #endif /* CONFIG_TRACING */ /* - * min()/max()/clamp() macros that also do - * strict type-checking.. See the - * "unnecessary" pointer comparison. + * min()/max()/clamp() macros must accomplish three things: + * + * - avoid multiple evaluations of the arguments (so side-effects like + * "x++" happen only once) when non-constant. + * - perform strict type-checking (to generate warnings instead of + * nasty runtime surprises). See the "unnecessary" pointer comparison + * in __typecheck(). + * - retain result as a constant expressions when called with only + * constant expressions (to avoid tripping VLA warnings in stack + * allocation usage). + */ +#define __typecheck(x, y) \ + (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) + +/* + * This returns a constant expression while determining if an argument is + * a constant expression, most importantly without evaluating the argument. + * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de> */ -#define __min(t1, t2, min1, min2, x, y) ({ \ - t1 min1 = (x); \ - t2 min2 = (y); \ - (void) (&min1 == &min2); \ - min1 < min2 ? min1 : min2; }) +#define __is_constexpr(x) \ + (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) + +#define __no_side_effects(x, y) \ + (__is_constexpr(x) && __is_constexpr(y)) + +#define __safe_cmp(x, y) \ + (__typecheck(x, y) && __no_side_effects(x, y)) + +#define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) + +#define __cmp_once(x, y, op) ({ \ + typeof(x) __x = (x); \ + typeof(y) __y = (y); \ + __cmp(__x, __y, op); }) + +#define __careful_cmp(x, y, op) \ + __builtin_choose_expr(__safe_cmp(x, y), \ + __cmp(x, y, op), __cmp_once(x, y, op)) /** * min - return minimum of two values of the same or compatible types * @x: first value * @y: second value */ -#define min(x, y) \ - __min(typeof(x), typeof(y), \ - __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ - x, y) - -#define __max(t1, t2, max1, max2, x, y) ({ \ - t1 max1 = (x); \ - t2 max2 = (y); \ - (void) (&max1 == &max2); \ - max1 > max2 ? max1 : max2; }) +#define min(x, y) __careful_cmp(x, y, <) /** * max - return maximum of two values of the same or compatible types * @x: first value * @y: second value */ -#define max(x, y) \ - __max(typeof(x), typeof(y), \ - __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \ - x, y) +#define max(x, y) __careful_cmp(x, y, >) /** * min3 - return minimum of three values @@ -878,10 +895,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } * @x: first value * @y: second value */ -#define min_t(type, x, y) \ - __min(type, type, \ - __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ - x, y) +#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <) /** * max_t - return maximum of two values, using the specified type @@ -889,10 +903,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } * @x: first value * @y: second value */ -#define max_t(type, x, y) \ - __max(type, type, \ - __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ - x, y) +#define max_t(type, x, y) __careful_cmp((type)(x), (type)(y), >) /** * clamp_t - return a value clamped to a given range using a given type |