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352c1d95e3
Historically, pt_regs have had orig_r8, an overloaded container for (1) backup copy of r8 (syscall number Trap Exceptions) (2) additional system state: (syscall/Exception/Interrupt) There is no point in keeping (1) since syscall number is never clobbered in-place, in pt_regs, unlike r0 which duals as first syscall arg as well as syscall return value and in case of syscall restart, the orig arg0 needs restoring (from orig_r0) after having been updated in-place with syscall ret value. This further paves way to convert (2) to contain ECR itself (rather than current madeup values) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _ASM_ARC_SYSCALL_H
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#define _ASM_ARC_SYSCALL_H 1
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <asm/unistd.h>
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#include <asm/ptrace.h> /* in_syscall() */
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static inline long
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syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
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{
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if (user_mode(regs) && in_syscall(regs))
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return regs->r8;
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else
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return -1;
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}
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static inline void
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syscall_rollback(struct task_struct *task, struct pt_regs *regs)
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{
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regs->r0 = regs->orig_r0;
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}
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static inline long
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syscall_get_error(struct task_struct *task, struct pt_regs *regs)
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{
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/* 0 if syscall succeeded, otherwise -Errorcode */
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return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
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}
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static inline long
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syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
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{
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return regs->r0;
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}
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static inline void
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syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
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int error, long val)
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{
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regs->r0 = (long) error ?: val;
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}
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/*
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* @i: argument index [0,5]
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* @n: number of arguments; n+i must be [1,6].
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*/
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static inline void
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syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
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unsigned int i, unsigned int n, unsigned long *args)
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{
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unsigned long *inside_ptregs = &(regs->r0);
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inside_ptregs -= i;
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BUG_ON((i + n) > 6);
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while (n--) {
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args[i++] = (*inside_ptregs);
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inside_ptregs--;
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}
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}
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#endif
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