Re: [PATCH] Return real errno from execve in ____call_usermodehelper

[Arnd Bergmann <arnd@arndb.de>]

On Saturday 19 August 2006 10:42, Russell King wrote:
> Maybe what we should be thinking of doing is changing execve() calls
> to kernel_execve() which returns the error code.
> 
> This way, architectures are free to implement execve() whatever way
> they wish - and if they're concerned about using errno, that's their
> own implementation specific detail.

Sounds good, it means we could finally kill __KERNEL_SYSCALLS__ along
with lib/errno.c.

I guess a fallback for those that haven't yet done kernel_execve could be

#ifdef CONFIG_ARCH_KERNEL_EXECVE
extern int kernel_execve(const char *filename,
		char *const argv[], char *const envp[]);
#else
static inline int kernel_execve(const char *filename,
		char *const argv[], char *const envp[]);
{
	int errno;
	mm_segment_t old_fs = get_fs();
	set_fs(KERNEL_DS);
	/* the kernel syscall macro modifies errno */
	execve(filename, argv, envp);
	set_fs(old_fs);
	return errno;
}
#endif

With that in place, we can remove the global errno right away, and the
kernel syscalls for any architecture that implements its own kernel_execve.

	Arnd <><