sparc64: switch to generic kernel_execve()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/sparc/Kconfig

@@ -75,6 +75,7 @@ config SPARC64
 	select HAVE_C_RECORDMCOUNT
 	select NO_BOOTMEM
 	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 
 config ARCH_DEFCONFIG
 	string

arch/sparc/kernel/sys_sparc_64.c

@@ -729,25 +729,3 @@ SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
 
 	return ret;
 }
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	long __res;
-	register long __g1 __asm__ ("g1") = __NR_execve;
-	register long __o0 __asm__ ("o0") = (long)(filename);
-	register long __o1 __asm__ ("o1") = (long)(argv);
-	register long __o2 __asm__ ("o2") = (long)(envp);
-	asm volatile ("t 0x6d\n\t"
-		      "sub %%g0, %%o0, %0\n\t"
-		      "movcc %%xcc, %%o0, %0\n\t"
-		      : "=r" (__res), "=&r" (__o0)
-		      : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
-		      : "cc");
-	return __res;
-}

arch/sparc/kernel/syscalls.S

@@ -115,13 +115,13 @@ ret_from_syscall:
 	call	schedule_tail
 	 mov	%g7, %o0
 	ldx	[%sp + PTREGS_OFF + PT_V9_I0], %o0
-	brnz,a,pt	%o0, ret_sys_call
+	brnz,pt	%o0, ret_sys_call
 	 ldx	[%g6 + TI_FLAGS], %l0
-	ldx	[%sp + PTREGS_OFF + PT_V9_G1], %l0
-	call	%l0
+	ldx	[%sp + PTREGS_OFF + PT_V9_G1], %l1
+	call	%l1
 	 ldx	[%sp + PTREGS_OFF + PT_V9_G2], %o0
-	call	do_exit	! will not return
-	 mov	0,%o0
+	ba,pt	%xcc, ret_sys_call
+	 mov	0, %o0
 
 	.globl	sparc_exit
 	.type	sparc_exit,#function