frv: switch to generic kernel_execve

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/frv/include/asm/processor.h

@@ -92,14 +92,12 @@ extern struct task_struct *__kernel_current_task;
 
 /*
  * do necessary setup to start up a newly executed thread.
- * - need to discard the frame stacked by init() invoking the execve syscall
  */
 #define start_thread(_regs, _pc, _usp)			\
 do {							\
-	__frame = __kernel_frame0_ptr;			\
-	__frame->pc	= (_pc);			\
-	__frame->psr	&= ~PSR_S;			\
-	__frame->sp	= (_usp);			\
+	_regs->pc	= (_pc);			\
+	_regs->psr	&= ~PSR_S;			\
+	_regs->sp	= (_usp);			\
 } while(0)
 
 /* Free all resources held by a thread. */

arch/frv/include/asm/unistd.h

@@ -373,6 +373,7 @@
 #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/frv/kernel/Makefile

@@ -8,7 +8,7 @@ heads-$(CONFIG_MMU)		:= head-mmu-fr451.o
 extra-y:= head.o vmlinux.lds
 
 obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o \
-	 kernel_execve.o process.o traps.o ptrace.o signal.o dma.o \
+	 process.o traps.o ptrace.o signal.o dma.o \
 	 sys_frv.o time.o setup.o frv_ksyms.o \
 	 debug-stub.o irq.o sleep.o uaccess.o
 

arch/frv/kernel/entry.S

@@ -871,6 +871,11 @@ ret_from_kernel_thread:
 	calll		@(gr21,gr0)
 	bra		sys_exit
 
+	.globl		ret_from_kernel_execve
+ret_from_kernel_execve:
+	ori		gr28,0,sp
+	bra		__syscall_exit
+
 ###################################################################################################
 #
 # Return to user mode is not as complex as all this looks,

arch/frv/kernel/kernel_execve.S

-/* in-kernel program execution
- *
- * Copyright (C) 2006 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 License
- * as published by the Free Software Foundation; either version
- * 2 of the License, 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: GR8/GR9/GR10: arguments to function
-# On return: GR8: syscall return.
-#
-###############################################################################
-	.globl		kernel_execve
-	.type		kernel_execve,@function
-kernel_execve:
-	setlos		__NR_execve,gr7
-	tira		gr0,#0
-	bralr
-
-	.size		kernel_execve,.-kernel_execve