96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
/*
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* Magic syscall break down functions
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*
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* Copyright 2010 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#ifndef __ASM_BLACKFIN_SYSCALL_H__
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#define __ASM_BLACKFIN_SYSCALL_H__
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/*
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* Blackfin syscalls are simple:
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* enter:
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* p0: syscall number
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* r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5
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* exit:
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* r0: return/error value
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*/
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <asm/ptrace.h>
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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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return regs->p0;
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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->p0 = regs->orig_p0;
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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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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 = error ? -error : val;
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}
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/**
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* syscall_get_arguments()
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* @task: unused
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* @regs: the register layout to extract syscall arguments from
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* @i: first syscall argument to extract
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* @n: number of syscall arguments to extract
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* @args: array to return the syscall arguments in
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*
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* args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument
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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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/*
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* Assume the ptrace layout doesn't change -- r5 is first in memory,
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* then r4, ..., then r0. So we simply reverse the ptrace register
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* array in memory to store into the args array.
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*/
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long *aregs = ®s->r0 - i;
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BUG_ON(i > 5 || i + n > 6);
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while (n--)
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*args++ = *aregs--;
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}
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/* See syscall_get_arguments() comments */
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static inline void
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syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
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unsigned int i, unsigned int n, const unsigned long *args)
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{
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long *aregs = ®s->r0 - i;
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BUG_ON(i > 5 || i + n > 6);
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while (n--)
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*aregs-- = *args++;
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}
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#endif
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