Re: [PATCH] syscalls: Update the syscall #defines to match uapi

From: Arnd Bergmann
Date: Mon Aug 12 2019 - 05:49:15 EST

On Sat, Aug 10, 2019 at 3:11 AM Alistair Francis
<alistair.francis@xxxxxxx> wrote:
> Update the #defines around sys_fstat64() and sys_fstatat64() to match
> the #defines around the __NR3264_fstatat and __NR3264_fstat definitions
> in include/uapi/asm-generic/unistd.h. This avoids compiler failures if
> one is defined.

What is the compiler failure you get?

> Signed-off-by: Alistair Francis <alistair.francis@xxxxxxx>
> ---
> include/linux/syscalls.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index 2bcef4c70183..e4bf5e480d60 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -512,7 +512,7 @@ asmlinkage long sys_readlinkat(int dfd, const char __user *path, char __user *bu
> asmlinkage long sys_newfstatat(int dfd, const char __user *filename,
> struct stat __user *statbuf, int flag);
> asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf);
> -#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
> +#if defined(__ARCH_WANT_NEW_STAT) || defined(__ARCH_WANT_STAT64)
> asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user *statbuf);
> asmlinkage long sys_fstatat64(int dfd, const char __user *filename,
> struct stat64 __user *statbuf, int flag);

I think this is wrong: when __ARCH_WANT_NEW_STAT is set, we are
on a 64-bit architecture and only want the sys_newfstat{,at} system
calls, not sys_fstat{,at}64 that gets used on 32-bit machines.

The #if check in the syscalls.h file also matches the definition of
the function.