Re: [PATCH] linux: Fix fstatat with !XSTAT_IS_XSTAT64 and __TIMESIZE=64 (BZ #29730)

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 28/10/22 17:54, Aurelien Jarno wrote:
> Commit 6e8a0aac2f883 ("time: Fix overflow itimer tests on 32-bit
> systems") changed in_time_t_range to assume a 32-bit time_t. Therefore
> stop calling it from __fstatat for systems with 64-bit time_t.
> 
> Resolves: BZ #29730

Although this change is not incorrect, I think the fix I just sent [1] is 
slight better because it just alias non-LFS stat to LFS stat for mips 
(which is also a small runtime and code optimization), while avoiding 
touching generic code (so we need to check if trigger another issue on 
different architecture).

[1] https://sourceware.org/pipermail/libc-alpha/2022-October/143089.html

> ---
>  sysdeps/unix/sysv/linux/fstatat.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/fstatat.c b/sysdeps/unix/sysv/linux/fstatat.c
> index 055fb4762e..afe93b6cf4 100644
> --- a/sysdeps/unix/sysv/linux/fstatat.c
> +++ b/sysdeps/unix/sysv/linux/fstatat.c
> @@ -33,9 +33,13 @@ __fstatat (int fd, const char *file, struct stat *buf, int flag)
>        if (! in_ino_t_range (st64.st_ino)
>  	  || ! in_off_t_range (st64.st_size)
>  	  || ! in_blkcnt_t_range (st64.st_blocks)
> +/* in_time_t_range assumes that all usages are for sizeof(time_t) == 32.  */
> +# if __TIMESIZE != 64
>  	  || ! in_time_t_range (st64.st_atim.tv_sec)
>  	  || ! in_time_t_range (st64.st_mtim.tv_sec)
> -	  || ! in_time_t_range (st64.st_ctim.tv_sec))
> +	  || ! in_time_t_range (st64.st_ctim.tv_sec)
> +# endif
> +	 )
>  	return INLINE_SYSCALL_ERROR_RETURN_VALUE (EOVERFLOW);
>  
>        /* Clear internal pad and reserved fields.  */