On Tue, 2025-07-29 at 09:17 -0700, Yonghong Song wrote:
>
> On 7/29/25 2:45 AM, Achill Gilgenast wrote:
> > If not fn_name, mod_len does never get initialized which fails now with
> > gcc15 on Alpine Linux edge:
> >
> > libbpf.c: In function 'find_kernel_btf_id.constprop':
> > libbpf.c:10100:33: error: 'mod_len' may be used uninitialized [-Werror=maybe-uninitialized]
> > 10100 | if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0)
> > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > libbpf.c:10070:21: note: 'mod_len' was declared here
> > 10070 | int ret, i, mod_len;
> > | ^~~~~~~
> >
> > Fixes: 8f8a024272f3 ("libbpf: support "module: Function" syntax for tracing programs")
> > Signed-off-by: Achill Gilgenast <fossdd@xxxxxxxxxx>
>
> The code itself is actually okay. The error is triggered due to'maybe-uninitialized'.
> To silence the compilation error, I think this change is okay.
>
> Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>
I agree with Yonghong, `mod_len` is only read if mod_name != NULL,
meaning that "if (fn_name) { ... mod_name = ...; mod_len = ... }"
block was executed.
Please drop the "Fixes" tag.
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
[...]
