/*
* OpenRISC ptrace.c
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* Modifications for the OpenRISC architecture:
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
* Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.com>
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <stddef.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/audit.h>
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <asm/thread_info.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
/*
* Copy the thread state to a regset that can be interpreted by userspace.
*
* It doesn't matter what our internal pt_regs structure looks like. The
* important thing is that we export a consistent view of the thread state
* to userspace. As such, we need to make sure that the regset remains
* ABI compatible as defined by the struct user_regs_struct:
*
* (Each item is a 32-bit word)
* r0 = 0 (exported for clarity)
* 31 GPRS r1-r31
* PC (Program counter)
* SR (Supervision register)
*/
static int genregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user * ubuf)
{
const struct pt_regs *regs = task_pt_regs(target);
int ret;
/* r0 */
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4);
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
regs->gpr+1, 4, 4*32);
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
®s->pc, 4*32, 4*33);
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
®s->sr, 4*33, 4*34);
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
4*34, -1);
return ret;
}
/*
* Set the thread state from a regset passed in via ptrace
*/
static int genregs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user * ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
int ret;
/* ignore r0 */
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4);
/* r1 - r31 */
if (!ret)
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
regs->gpr+1, 4, 4*32);
/* PC */
if (!ret)
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
®s->pc, 4*32, 4*33);
/*
* Skip SR and padding... userspace isn't allowed to changes bits in
* the Supervision register
*/
if (!ret)
ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
4*33, -1);
return ret;
}
/*
* Define the register sets available on OpenRISC under Linux
*/
enum or1k_regset {
REGSET_GENERAL,
};
static const struct user_regset or1k_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(long),
.align = sizeof(long),
.get = genregs_get,
.set = genregs_set,
},
};
static const struct user_regset_view user_or1k_native_view = {
.name = "or1k",
.e_machine = EM_OPENRISC,
.regsets = or1k_regsets,
.n = ARRAY_SIZE(or1k_regsets),
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_or1k_native_view;
}
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure the single step bit is not set.
*/
void ptrace_disable(struct task_struct *child)
{
pr_debug("ptrace_disable(): TODO\n");
user_disable_single_step(child);
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}
long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
unsigned long data)
{
int ret;
switch (request) {
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
/*
* Notification of system call entry/exit
* - triggered by current->work.syscall_trace
*/
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
tracehook_report_syscall_entry(regs))
/*
* Tracing decided this syscall should not happen.
* We'll return a bogus call number to get an ENOSYS
* error, but leave the original number in <something>.
*/
ret = -1L;
audit_syscall_entry(audit_arch(), regs->gpr[11],
regs->gpr[3], regs->gpr[4],
regs->gpr[5], regs->gpr[6]);
return ret ? : regs->gpr[11];
}
asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
{
int step;
audit_syscall_exit(regs);
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
}
