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/*
* 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;
}
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