On Wed, Apr 16, 2025 at 08:40:17PM +0200, Thomas Weißschuh wrote:
Both constructors and main() may be executed with different function signatures than they are actually using. This is intentional but trips up UBSAN.
Disable the function sanitizer of UBSAN in _start_c().
Signed-off-by: Thomas Weißschuh linux@weissschuh.net
tools/include/nolibc/crt.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h index c4b10103bbec50f1a3a0a4562e34fdbd1b43ce6f..961cfe777c3564e705dfdd581de828b374d05b0b 100644 --- a/tools/include/nolibc/crt.h +++ b/tools/include/nolibc/crt.h @@ -7,6 +7,8 @@ #ifndef _NOLIBC_CRT_H #define _NOLIBC_CRT_H +#include "compiler.h"
char **environ __attribute__((weak)); const unsigned long *_auxv __attribute__((weak)); @@ -25,6 +27,9 @@ extern void (*const __fini_array_end[])(void) __attribute__((weak)); void _start_c(long *sp); __attribute__((weak,used)) +#if __nolibc_has_feature(undefined_behavior_sanitizer)
- __attribute__((no_sanitize("function")))
+#endif
I'm wondering if it wouldn't be more reliable with:
#if __nolibc_has_attribute(no_sanitize) __attribute__((no_sanitize("function"))) #endif
Because in the end, what you want is to always place that attribute whenever it's supported, no ?
void _start_c(long *sp) { long argc;
Willy