android_kernel_xiaomi_sm8350/arch/m68knommu/kernel/entry.S
Wilson Callan 2d7f16d6d1 m68knommu: fix signal handling return path
The return from software signal handling pushes code on the stack
that system calls to the kernels cleanup code. This is borrowed
directly from the m68k linux signal handler.

The rt signal case is not quite right for the restricted instruction
set of the ColdFire parts. And neither the normal signal case or rt
signal case properly flushes/pushes the appropriate cache lines.

Rework the return path to just call back through some code fragments
in the kernel proper (with no MMU in the way we can do this). No
cache problems, and less code overall.

Original patch submitted by Wilson Callan <wcallan@savantav.com>

Greg fixed the rt signal return path to use the proper system call

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01 08:08:35 -07:00

152 lines
2.8 KiB
ArmAsm

/*
* linux/arch/m68knommu/kernel/entry.S
*
* Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
* Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
* Kenneth Albanowski <kjahds@kjahds.com>,
* Copyright (C) 2000 Lineo Inc. (www.lineo.com)
*
* Based on:
*
* linux/arch/m68k/kernel/entry.S
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file README.legal in the main directory of this archive
* for more details.
*
* Linux/m68k support by Hamish Macdonald
*
* 68060 fixes by Jesper Skov
* ColdFire support by Greg Ungerer (gerg@snapgear.com)
* 5307 fixes by David W. Miller
* linux 2.4 support David McCullough <davidm@snapgear.com>
*/
#include <linux/sys.h>
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/asm-offsets.h>
#include <asm/entry.h>
#include <asm/unistd.h>
.text
.globl buserr
.globl trap
.globl ret_from_exception
.globl ret_from_signal
.globl sys_fork
.globl sys_clone
.globl sys_vfork
ENTRY(buserr)
SAVE_ALL
moveq #-1,%d0
movel %d0,%sp@(PT_ORIG_D0)
movel %sp,%sp@- /* stack frame pointer argument */
jsr buserr_c
addql #4,%sp
jra ret_from_exception
ENTRY(trap)
SAVE_ALL
moveq #-1,%d0
movel %d0,%sp@(PT_ORIG_D0)
movel %sp,%sp@- /* stack frame pointer argument */
jsr trap_c
addql #4,%sp
jra ret_from_exception
#ifdef TRAP_DBG_INTERRUPT
.globl dbginterrupt
ENTRY(dbginterrupt)
SAVE_ALL
moveq #-1,%d0
movel %d0,%sp@(PT_ORIG_D0)
movel %sp,%sp@- /* stack frame pointer argument */
jsr dbginterrupt_c
addql #4,%sp
jra ret_from_exception
#endif
ENTRY(reschedule)
/* save top of frame */
pea %sp@
jbsr set_esp0
addql #4,%sp
pea ret_from_exception
jmp schedule
ENTRY(ret_from_fork)
movel %d1,%sp@-
jsr schedule_tail
addql #4,%sp
jra ret_from_exception
ENTRY(sys_fork)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr m68k_fork
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_vfork)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr m68k_vfork
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_clone)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr m68k_clone
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_sigsuspend)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr do_sigsuspend
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_rt_sigsuspend)
SAVE_SWITCH_STACK
pea %sp@(SWITCH_STACK_SIZE)
jbsr do_rt_sigsuspend
addql #4,%sp
RESTORE_SWITCH_STACK
rts
ENTRY(sys_sigreturn)
SAVE_SWITCH_STACK
jbsr do_sigreturn
RESTORE_SWITCH_STACK
rts
ENTRY(sys_rt_sigreturn)
SAVE_SWITCH_STACK
jbsr do_rt_sigreturn
RESTORE_SWITCH_STACK
rts
ENTRY(ret_from_user_signal)
moveq #__NR_sigreturn,%d0
trap #0
ENTRY(ret_from_user_rt_signal)
move #__NR_rt_sigreturn,%d0
trap #0