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| author | Kees Cook <keescook@chromium.org> | 2024-02-29 22:22:26 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2024-03-01 16:03:32 -0800 |
| commit | bd1ebf2467f9c5d157bec7b025e83f8ffdae1318 (patch) | |
| tree | 57b4a79108735efa9116de055fd038ef4014b96f /include/linux/overflow.h | |
| parent | e606e4b71798cc1df20e987dde2468e9527bd376 (diff) | |
overflow: Allow non-type arg to type_max() and type_min()
A common use of type_max() is to find the max for the type of a
variable. Using the pattern type_max(typeof(var)) is needlessly
verbose. Instead, since typeof(type) == type we can just explicitly
call typeof() on the argument to type_max() and type_min(). Add
wrappers for readability.
We can do some replacements right away:
$ git grep '\btype_\(min\|max\)(typeof' | wc -l
11
Link: https://lore.kernel.org/r/20240301062221.work.840-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include/linux/overflow.h')
| -rw-r--r-- | include/linux/overflow.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/overflow.h b/include/linux/overflow.h index bc390f026128..aa691f2119b0 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -31,8 +31,10 @@ * credit to Christian Biere. */ #define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type))) -#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T))) -#define type_min(T) ((T)((T)-type_max(T)-(T)1)) +#define __type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T))) +#define type_max(t) __type_max(typeof(t)) +#define __type_min(T) ((T)((T)-type_max(T)-(T)1)) +#define type_min(t) __type_min(typeof(t)) /* * Avoids triggering -Wtype-limits compilation warning, @@ -207,10 +209,10 @@ static inline bool __must_check __must_check_overflow(bool overflow) #define __overflows_type_constexpr(x, T) ( \ is_unsigned_type(typeof(x)) ? \ - (x) > type_max(typeof(T)) : \ + (x) > type_max(T) : \ is_unsigned_type(typeof(T)) ? \ - (x) < 0 || (x) > type_max(typeof(T)) : \ - (x) < type_min(typeof(T)) || (x) > type_max(typeof(T))) + (x) < 0 || (x) > type_max(T) : \ + (x) < type_min(T) || (x) > type_max(T)) #define __overflows_type(x, T) ({ \ typeof(T) v = 0; \ |