105 lines
2.4 KiB
C
105 lines
2.4 KiB
C
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/*
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* Access to user system call parameters and results
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*
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* Copyright (C) 2008 Imagination Technologies Ltd.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License v.2.
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*
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* See asm-generic/syscall.h for descriptions of what we must do here.
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*/
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#ifndef _ASM_METAG_SYSCALL_H
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#define _ASM_METAG_SYSCALL_H
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#include <linux/sched.h>
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#include <linux/err.h>
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#include <linux/uaccess.h>
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#include <asm/switch.h>
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static inline long syscall_get_nr(struct task_struct *task,
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struct pt_regs *regs)
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{
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unsigned long insn;
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/*
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* FIXME there's no way to find out how we got here other than to
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* examine the memory at the PC to see if it is a syscall
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* SWITCH instruction.
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*/
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if (get_user(insn, (unsigned long *)(regs->ctx.CurrPC - 4)))
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return -1;
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if (insn == __METAG_SW_ENCODING(SYS))
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return regs->ctx.DX[0].U1;
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else
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return -1L;
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}
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static inline void syscall_rollback(struct task_struct *task,
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struct pt_regs *regs)
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{
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/* do nothing */
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}
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static inline long syscall_get_error(struct task_struct *task,
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struct pt_regs *regs)
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{
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unsigned long error = regs->ctx.DX[0].U0;
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return IS_ERR_VALUE(error) ? error : 0;
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}
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static inline long syscall_get_return_value(struct task_struct *task,
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struct pt_regs *regs)
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{
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return regs->ctx.DX[0].U0;
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}
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static inline void syscall_set_return_value(struct task_struct *task,
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struct pt_regs *regs,
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int error, long val)
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{
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regs->ctx.DX[0].U0 = (long) error ?: val;
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}
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static inline void syscall_get_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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unsigned long *args)
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{
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unsigned int reg, j;
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BUG_ON(i + n > 6);
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for (j = i, reg = 6 - i; j < (i + n); j++, reg--) {
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if (reg % 2)
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args[j] = regs->ctx.DX[(reg + 1) / 2].U0;
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else
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args[j] = regs->ctx.DX[reg / 2].U1;
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}
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}
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static inline void syscall_set_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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const unsigned long *args)
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{
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unsigned int reg;
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BUG_ON(i + n > 6);
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for (reg = 6 - i; i < (i + n); i++, reg--) {
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if (reg % 2)
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regs->ctx.DX[(reg + 1) / 2].U0 = args[i];
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else
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regs->ctx.DX[reg / 2].U1 = args[i];
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}
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}
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#define NR_syscalls __NR_syscalls
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/* generic syscall table */
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extern const void *sys_call_table[];
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#endif /* _ASM_METAG_SYSCALL_H */
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