151 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			151 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * linux/arch/unicore32/kernel/ptrace.c
 | |
|  *
 | |
|  * Code specific to PKUnity SoC and UniCore ISA
 | |
|  *
 | |
|  * Copyright (C) 2001-2010 GUAN Xue-tao
 | |
|  *
 | |
|  * By Ross Biro 1/23/92
 | |
|  *
 | |
|  * This program is free software; you can redistribute it and/or modify
 | |
|  * it under the terms of the GNU General Public License version 2 as
 | |
|  * published by the Free Software Foundation.
 | |
|  */
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/ptrace.h>
 | |
| #include <linux/signal.h>
 | |
| #include <linux/uaccess.h>
 | |
| #include <linux/sched/task_stack.h>
 | |
| 
 | |
| /*
 | |
|  * this routine will get a word off of the processes privileged stack.
 | |
|  * the offset is how far from the base addr as stored in the THREAD.
 | |
|  * this routine assumes that all the privileged stacks are in our
 | |
|  * data space.
 | |
|  */
 | |
| static inline long get_user_reg(struct task_struct *task, int offset)
 | |
| {
 | |
| 	return task_pt_regs(task)->uregs[offset];
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * this routine will put a word on the processes privileged stack.
 | |
|  * the offset is how far from the base addr as stored in the THREAD.
 | |
|  * this routine assumes that all the privileged stacks are in our
 | |
|  * data space.
 | |
|  */
 | |
| static inline int
 | |
| put_user_reg(struct task_struct *task, int offset, long data)
 | |
| {
 | |
| 	struct pt_regs newregs, *regs = task_pt_regs(task);
 | |
| 	int ret = -EINVAL;
 | |
| 
 | |
| 	newregs = *regs;
 | |
| 	newregs.uregs[offset] = data;
 | |
| 
 | |
| 	if (valid_user_regs(&newregs)) {
 | |
| 		regs->uregs[offset] = data;
 | |
| 		ret = 0;
 | |
| 	}
 | |
| 
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Called by kernel/ptrace.c when detaching..
 | |
|  */
 | |
| void ptrace_disable(struct task_struct *child)
 | |
| {
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * We actually access the pt_regs stored on the kernel stack.
 | |
|  */
 | |
| static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 | |
| 			    unsigned long __user *ret)
 | |
| {
 | |
| 	unsigned long tmp;
 | |
| 
 | |
| 	tmp = 0;
 | |
| 	if (off < sizeof(struct pt_regs))
 | |
| 		tmp = get_user_reg(tsk, off >> 2);
 | |
| 
 | |
| 	return put_user(tmp, ret);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * We actually access the pt_regs stored on the kernel stack.
 | |
|  */
 | |
| static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 | |
| 			     unsigned long val)
 | |
| {
 | |
| 	if (off >= sizeof(struct pt_regs))
 | |
| 		return 0;
 | |
| 
 | |
| 	return put_user_reg(tsk, off >> 2, val);
 | |
| }
 | |
| 
 | |
| long arch_ptrace(struct task_struct *child, long request,
 | |
| 		 unsigned long addr, unsigned long data)
 | |
| {
 | |
| 	int ret;
 | |
| 	unsigned long __user *datap = (unsigned long __user *) data;
 | |
| 
 | |
| 	switch (request) {
 | |
| 	case PTRACE_PEEKUSR:
 | |
| 		ret = ptrace_read_user(child, addr, datap);
 | |
| 		break;
 | |
| 
 | |
| 	case PTRACE_POKEUSR:
 | |
| 		ret = ptrace_write_user(child, addr, data);
 | |
| 		break;
 | |
| 
 | |
| 	case PTRACE_GET_THREAD_AREA:
 | |
| 		ret = put_user(task_pt_regs(child)->UCreg_16,
 | |
| 			       datap);
 | |
| 		break;
 | |
| 
 | |
| 	default:
 | |
| 		ret = ptrace_request(child, request, addr, data);
 | |
| 		break;
 | |
| 	}
 | |
| 
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 | |
| {
 | |
| 	unsigned long ip;
 | |
| 
 | |
| 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 | |
| 		return scno;
 | |
| 	if (!(current->ptrace & PT_PTRACED))
 | |
| 		return scno;
 | |
| 
 | |
| 	/*
 | |
| 	 * Save IP.  IP is used to denote syscall entry/exit:
 | |
| 	 *  IP = 0 -> entry, = 1 -> exit
 | |
| 	 */
 | |
| 	ip = regs->UCreg_ip;
 | |
| 	regs->UCreg_ip = why;
 | |
| 
 | |
| 	current_thread_info()->syscall = scno;
 | |
| 
 | |
| 	/* the 0x80 provides a way for the tracing parent to distinguish
 | |
| 	   between a syscall stop and SIGTRAP delivery */
 | |
| 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 | |
| 				 ? 0x80 : 0));
 | |
| 	/*
 | |
| 	 * this isn't the same as continuing with a signal, but it will do
 | |
| 	 * for normal use.  strace only continues with a signal if the
 | |
| 	 * stopping signal is not SIGTRAP.  -brl
 | |
| 	 */
 | |
| 	if (current->exit_code) {
 | |
| 		send_sig(current->exit_code, current, 1);
 | |
| 		current->exit_code = 0;
 | |
| 	}
 | |
| 	regs->UCreg_ip = ip;
 | |
| 
 | |
| 	return current_thread_info()->syscall;
 | |
| }
 | 
