Register 2 is alredy overwritten by the return value when syscall_trace_leave() is called. Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9187/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
		
			
				
	
	
		
			141 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Access to user system call parameters and results
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 *
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 * This file is subject to the terms and conditions of the GNU General Public
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 * License.  See the file "COPYING" in the main directory of this archive
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 * for more details.
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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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 * Copyright (C) 2012 Ralf Baechle <ralf@linux-mips.org>
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 */
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#ifndef __ASM_MIPS_SYSCALL_H
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#define __ASM_MIPS_SYSCALL_H
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#include <linux/compiler.h>
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#include <uapi/linux/audit.h>
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#include <linux/elf-em.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/unistd.h>
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#ifndef __NR_syscall /* Only defined if _MIPS_SIM == _MIPS_SIM_ABI32 */
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#define __NR_syscall 4000
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#endif
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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 current_thread_info()->syscall;
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}
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static inline unsigned long mips_get_syscall_arg(unsigned long *arg,
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	struct task_struct *task, struct pt_regs *regs, unsigned int n)
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{
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	unsigned long usp __maybe_unused = regs->regs[29];
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	switch (n) {
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	case 0: case 1: case 2: case 3:
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		*arg = regs->regs[4 + n];
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		return 0;
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#ifdef CONFIG_32BIT
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	case 4: case 5: case 6: case 7:
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		return get_user(*arg, (int *)usp + n);
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#endif
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#ifdef CONFIG_64BIT
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	case 4: case 5: case 6: case 7:
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#ifdef CONFIG_MIPS32_O32
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		if (test_thread_flag(TIF_32BIT_REGS))
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			return get_user(*arg, (int *)usp + n);
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		else
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#endif
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			*arg = regs->regs[4 + n];
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		return 0;
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#endif
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	default:
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		BUG();
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	}
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	unreachable();
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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->regs[2];
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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 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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	if (error) {
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		regs->regs[2] = -error;
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		regs->regs[7] = -1;
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	} else {
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		regs->regs[2] = val;
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		regs->regs[7] = 0;
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	}
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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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	int ret;
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	/* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */
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	if ((config_enabled(CONFIG_32BIT) ||
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	    test_tsk_thread_flag(task, TIF_32BIT_REGS)) &&
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	    (regs->regs[2] == __NR_syscall)) {
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		i++;
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		n++;
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	}
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	while (n--)
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		ret |= mips_get_syscall_arg(args++, task, regs, i++);
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	/*
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	 * No way to communicate an error because this is a void function.
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	 */
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#if 0
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	return ret;
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#endif
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}
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extern const unsigned long sys_call_table[];
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extern const unsigned long sys32_call_table[];
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extern const unsigned long sysn32_call_table[];
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static inline int syscall_get_arch(void)
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{
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	int arch = AUDIT_ARCH_MIPS;
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#ifdef CONFIG_64BIT
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	if (!test_thread_flag(TIF_32BIT_REGS)) {
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		arch |= __AUDIT_ARCH_64BIT;
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		/* N32 sets only TIF_32BIT_ADDR */
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		if (test_thread_flag(TIF_32BIT_ADDR))
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			arch |= __AUDIT_ARCH_CONVENTION_MIPS64_N32;
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	}
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#endif
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#if defined(__LITTLE_ENDIAN)
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	arch |=  __AUDIT_ARCH_LE;
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#endif
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	return arch;
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}
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#endif	/* __ASM_MIPS_SYSCALL_H */
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