Hi Jakub, Ankit,
On 28/11/2025 02:00, Jakub Kicinski wrote:
On Wed, 26 Nov 2025 17:55:14 +0100 Matthieu Baerts wrote:
I confirm this, I can reproduce the warning with Clang 21.
It is indeed a false positive, because the code does that:
if (addr.ss_family == AF_INET) raw_addr = &(((struct sockaddr_in *)&addr)->sin_addr); else if (addr.ss_family == AF_INET6) raw_addr = &(((struct sockaddr_in6 *)&addr)->sin6_addr); else xerror("bad family");
"xerror()" calls "exit(1)", so "raw_addr" is never used uninitialized.
I'm not sure why Clang 21 reports that now, and not before, but well, the modification you did in the selftests doesn't hurt:
I think annotating xerror with __noreturn is a better fix.
Good idea, I didn't know about that!
Thank you for the review!
Including kselftest.h will be needed.
Because mptcp_connect.c is a tool that is used by other selftests, but it doesn't interact directly with the selftests, maybe we don't need to include it, and only add this #define in mptcp_connect.c?
#define __noreturn __attribute__((__noreturn__))
(I don't know if a #ifndef/#endif is needed.)
That's a detail, I guess either is fine and shouldn't cause other issues.
Cheers, Matt