From: Thomas Weißschuh Date: Wed, 1 Apr 2026 15:07:27 +0000 (+0200) Subject: tools/nolibc: use __builtin_offsetof() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fd2e9f820005d63769a6662c276b1f52a72ed041;p=thirdparty%2Fkernel%2Flinux.git tools/nolibc: use __builtin_offsetof() The current custom implementation of offsetof() fails UBSAN: runtime error: member access within null pointer of type 'struct ...' This means that all its users, including container_of(), free() and realloc(), fail. Use __builtin_offsetof() instead which does not have this issue and has been available since GCC 4 and clang 3. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://patch.msgid.link/20260401-nolibc-asprintf-v1-1-46292313439f@weissschuh.net --- diff --git a/tools/include/nolibc/stddef.h b/tools/include/nolibc/stddef.h index ecbd13eab1f51..a3976341afdd7 100644 --- a/tools/include/nolibc/stddef.h +++ b/tools/include/nolibc/stddef.h @@ -18,7 +18,7 @@ #endif #ifndef offsetof -#define offsetof(TYPE, FIELD) ((size_t) &((TYPE *)0)->FIELD) +#define offsetof(TYPE, FIELD) __builtin_offsetof(TYPE, FIELD) #endif #endif /* _NOLIBC_STDDEF_H */