generic sys_execve()

Selected by __ARCH_WANT_SYS_EXECVE in unistd.h.  Requires
	* working current_pt_regs()
	* *NOT* doing a syscall-in-kernel kind of kernel_execve()
implementation.  Using generic kernel_execve() is fine.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 09b28b7..c4be3f5 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -289,8 +289,12 @@
 		const struct compat_iovec __user *vec,
 		unsigned long vlen, u32 pos_low, u32 pos_high);
 
-int compat_do_execve(char *filename, compat_uptr_t __user *argv,
-		     compat_uptr_t __user *envp, struct pt_regs *regs);
+int compat_do_execve(const char *filename, const compat_uptr_t __user *argv,
+		     const compat_uptr_t __user *envp, struct pt_regs *regs);
+#ifdef __ARCH_WANT_SYS_EXECVE
+asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv,
+		     const compat_uptr_t __user *envp);
+#endif
 
 asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
 		compat_ulong_t __user *outp, compat_ulong_t __user *exp,