linux/arch/arc/kernel/asm-offsets.c
Vineet Gupta 5c39c0ab5e ARC: [Review] Preparing to fix incorrect syscall restarts due to signals
To avoid multiple syscall restarts (multiple signals) or no restart at
all (sigreturn), we need just an extra bit of state "literally 1 bit" in
struct pt_regs. orig_r8 is the best place to do this, however given the
way it is encoded currently, we can't add anything simplistically.

Current orig_r8:
* syscalls   -> 1 to NR_SYSCALLS
* Exceptions -> NR_SYSCALLS + 1
* Break-point-> NR_SYSCALLS + 2

In new scheme it is a bit-field
* lower short word contains the  exact event type (and a new bit to represent
   restart semantics : if syscall was already / can't be restarted)
* upper short word optionally containing the syscall num - needed by
  likes of tracehooks etc

This patch only changes how orig_r8 is organised and nothing should
change behaviourily.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-02-15 23:15:49 +05:30

62 lines
1.8 KiB
C

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/thread_info.h>
#include <linux/kbuild.h>
#include <asm/hardirq.h>
#include <asm/page.h>
#include <asm/ptrace.h>
int main(void)
{
DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));
DEFINE(TASK_THREAD_INFO, offsetof(struct task_struct, stack));
BLANK();
DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp));
DEFINE(THREAD_CALLEE_REG, offsetof(struct thread_struct, callee_reg));
DEFINE(THREAD_FAULT_ADDR,
offsetof(struct thread_struct, fault_address));
BLANK();
DEFINE(THREAD_INFO_FLAGS, offsetof(struct thread_info, flags));
DEFINE(THREAD_INFO_PREEMPT_COUNT,
offsetof(struct thread_info, preempt_count));
BLANK();
DEFINE(TASK_ACT_MM, offsetof(struct task_struct, active_mm));
DEFINE(TASK_TGID, offsetof(struct task_struct, tgid));
DEFINE(MM_CTXT, offsetof(struct mm_struct, context));
DEFINE(MM_PGD, offsetof(struct mm_struct, pgd));
DEFINE(MM_CTXT_ASID, offsetof(mm_context_t, asid));
BLANK();
DEFINE(PT_status32, offsetof(struct pt_regs, status32));
DEFINE(PT_orig_r8, offsetof(struct pt_regs, orig_r8_word));
DEFINE(PT_sp, offsetof(struct pt_regs, sp));
DEFINE(PT_r0, offsetof(struct pt_regs, r0));
DEFINE(PT_r1, offsetof(struct pt_regs, r1));
DEFINE(PT_r2, offsetof(struct pt_regs, r2));
DEFINE(PT_r3, offsetof(struct pt_regs, r3));
DEFINE(PT_r4, offsetof(struct pt_regs, r4));
DEFINE(PT_r5, offsetof(struct pt_regs, r5));
DEFINE(PT_r6, offsetof(struct pt_regs, r6));
DEFINE(PT_r7, offsetof(struct pt_regs, r7));
return 0;
}