Re: [musl] [PATCH] set EINVAL for sigismember when sig is invalid

[Thorsten Glaser <tg@evolvis.org>]

On Tue, 29 Oct 2024, lihua.zhao.cn@windriver.com wrote:

> int sigismember(const sigset_t *set, int sig)
> {
> 	unsigned s = sig-1;
>-	if (s >= _NSIG-1) return 0;
>+	if (s < 0 || s >= _NSIG-1) {

unsigned s can never be 0, and assignment from int will wrap around,
so the >= is enough.

There’s UB if sig == INT_MIN though.

- 	unsigned s = sig-1;
+ 	unsigned s = sig;
+ 	++s;

Or:

- 	unsigned s = sig-1;
+ 	unsigned s = (unsigned)sig - 1U;

bye,
//mirabilos
-- 
In traditional syntax ' is ignored, but in c99 everything between two ' is
handled as character constant.  Therefore you cannot use ' in a preproces-
sing file in c99 mode.	-- Ragge
No faith left in ISO C99, undefined behaviour, etc.