forked from mirrors/linux
b6ef5bb3d9
Add an explicit TIF_SYSCALL bit that indicates if a task is inside a system call. The svc_code in the pt_regs structure is now only valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC can be replaced with TIF_SYSCALL. Overall do_signal is a bit more readable and it saves a few lines of code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
/*
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* Access to user system call parameters and results
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*
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* Copyright IBM Corp. 2008
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.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 only)
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* as published by the Free Software Foundation.
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*/
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#ifndef _ASM_SYSCALL_H
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#define _ASM_SYSCALL_H 1
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#include <linux/sched.h>
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#include <linux/err.h>
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#include <asm/ptrace.h>
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/*
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* The syscall table always contains 32 bit pointers since we know that the
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* address of the function to be called is (way) below 4GB. So the "int"
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* type here is what we want [need] for both 32 bit and 64 bit systems.
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*/
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extern const unsigned int sys_call_table[];
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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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return test_tsk_thread_flag(task, TIF_SYSCALL) ?
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(regs->svc_code & 0xffff) : -1;
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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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regs->gprs[2] = regs->orig_gpr2;
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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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return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 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->gprs[2];
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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->gprs[2] = error ? -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 long mask = -1UL;
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BUG_ON(i + n > 6);
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#ifdef CONFIG_COMPAT
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if (test_tsk_thread_flag(task, TIF_31BIT))
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mask = 0xffffffff;
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#endif
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while (n-- > 0)
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if (i + n > 0)
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args[n] = regs->gprs[2 + i + n] & mask;
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if (i == 0)
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args[0] = regs->orig_gpr2 & mask;
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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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BUG_ON(i + n > 6);
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while (n-- > 0)
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if (i + n > 0)
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regs->gprs[2 + i + n] = args[n];
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if (i == 0)
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regs->orig_gpr2 = args[0];
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}
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#endif /* _ASM_SYSCALL_H */
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