Messages in this thread Patch in this message | | | From | Bart Van Assche <> | Subject | [PATCH] kernel.h: Avoid that sparse complains about using sizeof(void) | Date | Thu, 5 Jul 2018 09:17:09 -0700 |
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The macro __is_constexpr() causes sparse to report the following:
warning: expression using sizeof(void)
Avoid this by using __builtin_constant_p() instead.
Fixes: 3c8ba0d61d04 ("kernel.h: Retain constant expression output for max()/min()") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Uecker <Martin.Uecker@med.uni-goettingen.de> Cc: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: <stable@vger.kernel.org> --- include/linux/kernel.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d23123238534..a9f0d0d48971 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -811,13 +811,19 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #define __typecheck(x, y) \ (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) +#ifndef __CHECKER__ /* * 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> + * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>. However, this + * macro causes sparse to report the warning "expression using sizeof(void)". + * Hence use __builtin_constant_p() instead when using sparse. */ #define __is_constexpr(x) \ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) +#else +#define __is_constexpr(x) __builtin_constant_p((x)) +#endif #define __no_side_effects(x, y) \ (__is_constexpr(x) && __is_constexpr(y)) -- 2.18.0
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