On 2025-04-19 11:11:40+0200, Willy Tarreau wrote:
On Wed, Apr 16, 2025 at 08:40:18PM +0200, Thomas Weißschuh wrote:
As byte buffer is overlaid with a 'struct dirent64'. it has to satisfy the structs alignment requirements.
Fixes: 665fa8dea90d ("tools/nolibc: add support for directory access") Signed-off-by: Thomas Weißschuh linux@weissschuh.net
Oh good catch! I already faced crashes in other programs due to AVX memcpy when doing similar casts without thinking about alignment.
@@ -58,6 +58,7 @@ int closedir(DIR *dirp) static __attribute__((unused)) int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) {
- __attribute__((aligned(__alignof__(struct linux_dirent64)))) char buf[sizeof(struct linux_dirent64) + NAME_MAX + 1];
I tend to find it more readable when the attribute is on the same line as the type on variables declaration, often at the end of the line, to keep declarations alignes, even if that makes longer lines. If alignment concerns come back often, we could maybe have __nolibc_align(<align>) and maybe even __nolibc_align_as(<type>) to slightly shorten the lines. Just an idea.
Sounds good, the attribute soup is annoying.
In any case: Acked-by: Willy Tarreau w@1wt.eu
Thanks!
Thomas