Thomas, Zhangjin, I've merged your latest patches in my branch 20230520-nolibc-rv32+stkp2, which was rebased to integrate the updated commit messages and a few missing s-o-b from mine. Please have a look: https://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git However, Thomas, I noticed something puzzling me. While I tested with gcc-9.5 (that I have here along my toolchains) I found that it would systematically fail: sysroot/x86/include/stackprotector.h:46:1: warning: 'no_stack_protector' attribute directive ignored [-Wattributes] 46 | { | ^ !!Stack smashing detected!! qemu: uncaught target signal 6 (Aborted) - core dumped 0 test(s) passed. The reason is that it doesn't support the attribute "no_stack_protector". Upon closer investigation, I noticed that _start() on x86_64 doens't have it, yet it works on more recent compilers! So I don't understand why it works with more recent compilers. I managed to avoid the crash by enclosing the __stack_chk_init() function in a #pragma GCC optimize("-fno-stack-protector") while removing the attribute (though Clang and more recent gcc use this attribute so we shouldn't completely drop it either). I consider this non-critical as we can expect that regtests are run with a reasonably recent compiler version, but if in the long term we can find a more reliable detection for this, it would be nice. For example I found that gcc defines __SSP_ALL__ to 1 when -fstack-protector is used, and 2 when -fstack-protector-all is used. With clang, it's 1 and 3 respectively. Maybe we should use that and drop NOLIBC_STACKPROTECTOR, that would be one less variable to deal with: the code would automatically adapt to whatever cflags the user sets on the compiler, which is generally better. Regards, Willy
