mn10300: switch to generic kernel_execve()

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

arch/mn10300/include/asm/frame.inc

@@ -61,7 +61,7 @@
 ###############################################################################
 .macro RESTORE_ALL
 	# peel back the stack to the calling frame
-	# - this permits execve() to discard extra frames due to kernel syscalls
+	# - we need that when returning from interrupts to kernel mode
 	GET_THREAD_INFO a0
 	mov	(TI_frame,a0),fp
 	mov	fp,sp

arch/mn10300/include/asm/processor.h

@@ -119,20 +119,13 @@ struct thread_struct {
 
 /*
  * do necessary setup to start up a newly executed thread
- * - need to discard the frame stacked by the kernel thread invoking the execve
- *   syscall (see RESTORE_ALL macro)
  */
 static inline void start_thread(struct pt_regs *regs,
 				unsigned long new_pc, unsigned long new_sp)
 {
-	struct thread_info *ti = current_thread_info();
-	struct pt_regs *frame0;
-
-	frame0 = thread_info_to_uregs(ti);
-	frame0->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
-	frame0->pc = new_pc;
-	frame0->sp = new_sp;
-	ti->frame = frame0;
+	regs->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
+	regs->pc = new_pc;
+	regs->sp = new_sp;
 }
 
 

arch/mn10300/include/asm/unistd.h

@@ -383,6 +383,7 @@
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/mn10300/kernel/Makefile

@@ -8,7 +8,7 @@ fpu-obj-$(CONFIG_FPU) := fpu.o fpu-low.o
 
 obj-y   := process.o signal.o entry.o traps.o irq.o \
 	   ptrace.o setup.o time.o sys_mn10300.o io.o \
-	   switch_to.o mn10300_ksyms.o kernel_execve.o $(fpu-obj-y) \
+	   switch_to.o mn10300_ksyms.o $(fpu-obj-y) \
 	   csrc-mn10300.o cevt-mn10300.o
 
 obj-$(CONFIG_SMP) += smp.o smp-low.o

arch/mn10300/kernel/entry.S

@@ -62,6 +62,13 @@ ENTRY(ret_from_kernel_thread)
 	calls	(a0)
 	jmp	sys_exit
 
+ENTRY(ret_from_kernel_execve)
+	add	-12,d0	/* pt_regs -> frame */
+	mov	d0,sp
+	GET_THREAD_INFO a2
+	clr	d0
+	jmp	syscall_exit
+
 ###############################################################################
 #
 # system call handler

arch/mn10300/kernel/kernel_execve.S

-/* MN10300 In-kernel program execution
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-#include <linux/linkage.h>
-#include <asm/unistd.h>
-
-###############################################################################
-#
-# 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, char *const argv[],
-#		    char *const envp[])
-#
-# On entry: D0/D1/8(SP): arguments to function
-# On return: D0: syscall return.
-#
-###############################################################################
-	.globl		kernel_execve
-	.type		kernel_execve,@function
-kernel_execve:
-	mov		a3,a1
-	mov		d0,a0
-	mov		(12,sp),a3
-	mov		+__NR_execve,d0
-	syscall		0
-	mov		a1,a3
-	rets
-
-	.size		kernel_execve,.-kernel_execve