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linux-next/arch/mips/kernel/entry.S
Linus Torvalds 9977d9b379 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 
Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild
2012-12-12 12:22:13 -08:00

213 lines
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ArmAsm
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/isadep.h>
#include <asm/thread_info.h>
#include <asm/war.h>
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/mipsmtregs.h>
#endif
#ifndef CONFIG_PREEMPT
#define resume_kernel restore_all
#else
#define __ret_from_irq ret_from_exception
#endif
.text
.align 5
#ifndef CONFIG_PREEMPT
FEXPORT(ret_from_exception)
local_irq_disable # preempt stop
b __ret_from_irq
#endif
FEXPORT(ret_from_irq)
LONG_S s0, TI_REGS($28)
FEXPORT(__ret_from_irq)
/*
* We can be coming here from a syscall done in the kernel space,
* e.g. a failed kernel_execve().
*/
resume_userspace_check:
LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
andi t0, t0, KU_USER
beqz t0, resume_kernel
resume_userspace:
local_irq_disable # make sure we dont miss an
# interrupt setting need_resched
# between sampling and return
LONG_L a2, TI_FLAGS($28) # current->work
andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
bnez t0, work_pending
j restore_all
#ifdef CONFIG_PREEMPT
resume_kernel:
local_irq_disable
lw t0, TI_PRE_COUNT($28)
bnez t0, restore_all
need_resched:
LONG_L t0, TI_FLAGS($28)
andi t1, t0, _TIF_NEED_RESCHED
beqz t1, restore_all
LONG_L t0, PT_STATUS(sp) # Interrupts off?
andi t0, 1
beqz t0, restore_all
jal preempt_schedule_irq
b need_resched
#endif
FEXPORT(ret_from_kernel_thread)
jal schedule_tail # a0 = struct task_struct *prev
move a0, s1
jal s0
j syscall_exit
FEXPORT(ret_from_fork)
jal schedule_tail # a0 = struct task_struct *prev
FEXPORT(syscall_exit)
local_irq_disable # make sure need_resched and
# signals dont change between
# sampling and return
LONG_L a2, TI_FLAGS($28) # current->work
li t0, _TIF_ALLWORK_MASK
and t0, a2, t0
bnez t0, syscall_exit_work
restore_all: # restore full frame
#ifdef CONFIG_MIPS_MT_SMTC
#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
/* Re-arm any temporarily masked interrupts not explicitly "acked" */
mfc0 v0, CP0_TCSTATUS
ori v1, v0, TCSTATUS_IXMT
mtc0 v1, CP0_TCSTATUS
andi v0, TCSTATUS_IXMT
_ehb
mfc0 t0, CP0_TCCONTEXT
DMT 9 # dmt t1
jal mips_ihb
mfc0 t2, CP0_STATUS
andi t3, t0, 0xff00
or t2, t2, t3
mtc0 t2, CP0_STATUS
_ehb
andi t1, t1, VPECONTROL_TE
beqz t1, 1f
EMT
1:
mfc0 v1, CP0_TCSTATUS
/* We set IXMT above, XOR should clear it here */
xori v1, v1, TCSTATUS_IXMT
or v1, v0, v1
mtc0 v1, CP0_TCSTATUS
_ehb
xor t0, t0, t3
mtc0 t0, CP0_TCCONTEXT
#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
/* Detect and execute deferred IPI "interrupts" */
LONG_L s0, TI_REGS($28)
LONG_S sp, TI_REGS($28)
jal deferred_smtc_ipi
LONG_S s0, TI_REGS($28)
#endif /* CONFIG_MIPS_MT_SMTC */
.set noat
RESTORE_TEMP
RESTORE_AT
RESTORE_STATIC
restore_partial: # restore partial frame
#ifdef CONFIG_TRACE_IRQFLAGS
SAVE_STATIC
SAVE_AT
SAVE_TEMP
LONG_L v0, PT_STATUS(sp)
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
and v0, ST0_IEP
#else
and v0, ST0_IE
#endif
beqz v0, 1f
jal trace_hardirqs_on
b 2f
1: jal trace_hardirqs_off
2:
RESTORE_TEMP
RESTORE_AT
RESTORE_STATIC
#endif
RESTORE_SOME
RESTORE_SP_AND_RET
.set at
work_pending:
andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
beqz t0, work_notifysig
work_resched:
jal schedule
local_irq_disable # make sure need_resched and
# signals dont change between
# sampling and return
LONG_L a2, TI_FLAGS($28)
andi t0, a2, _TIF_WORK_MASK # is there any work to be done
# other than syscall tracing?
beqz t0, restore_all
andi t0, a2, _TIF_NEED_RESCHED
bnez t0, work_resched
work_notifysig: # deal with pending signals and
# notify-resume requests
move a0, sp
li a1, 0
jal do_notify_resume # a2 already loaded
j resume_userspace_check
FEXPORT(syscall_exit_partial)
local_irq_disable # make sure need_resched doesn't
# change between and return
LONG_L a2, TI_FLAGS($28) # current->work
li t0, _TIF_ALLWORK_MASK
and t0, a2
beqz t0, restore_partial
SAVE_STATIC
syscall_exit_work:
LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
andi t0, t0, KU_USER
beqz t0, resume_kernel
li t0, _TIF_WORK_SYSCALL_EXIT
and t0, a2 # a2 is preloaded with TI_FLAGS
beqz t0, work_pending # trace bit set?
local_irq_enable # could let syscall_trace_leave()
# call schedule() instead
move a0, sp
jal syscall_trace_leave
b resume_userspace
#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT)
/*
* MIPS32R2 Instruction Hazard Barrier - must be called
*
* For C code use the inline version named instruction_hazard().
*/
LEAF(mips_ihb)
.set mips32r2
jr.hb ra
nop
END(mips_ihb)
#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */
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