/*
* `ptrace' system call
*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2004-2007 John Williams <john.williams@petalogix.com>
*
* derived from arch/v850/kernel/ptrace.c
*
* Copyright (C) 2002,03 NEC Electronics Corporation
* Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
*
* Derived from arch/mips/kernel/ptrace.c:
*
* Copyright (C) 1992 Ross Biro
* Copyright (C) Linus Torvalds
* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
* Copyright (C) 1996 David S. Miller
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999 MIPS Technologies, Inc.
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/asm-offsets.h>
/* Returns the address where the register at REG_OFFS in P is stashed away. */
static microblaze_reg_t *reg_save_addr(unsigned reg_offs,
struct task_struct *t)
{
struct pt_regs *regs;
/*
* Three basic cases:
*
* (1) A register normally saved before calling the scheduler, is
* available in the kernel entry pt_regs structure at the top
* of the kernel stack. The kernel trap/irq exit path takes
* care to save/restore almost all registers for ptrace'd
* processes.
*
* (2) A call-clobbered register, where the process P entered the
* kernel via [syscall] trap, is not stored anywhere; that's
* OK, because such registers are not expected to be preserved
* when the trap returns anyway (so we don't actually bother to
* test for this case).
*
* (3) A few registers not used at all by the kernel, and so
* normally never saved except by context-switches, are in the
* context switch state.
*/
/* Register saved during kernel entry (or not available). */
regs = task_pt_regs(t);
return (microblaze_reg_t *)((char *)regs + reg_offs);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
int rval;
unsigned long val = 0;
unsigned long copied;
switch (request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
pr_debug("PEEKTEXT/PEEKDATA at %08lX\n", addr);
copied = access_process_vm(child, addr, &val, sizeof(val), 0);
rval = -EIO;
if (copied != sizeof(val))
break;
rval = put_user(val, (unsigned long *)data);
break;
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
pr_debug("POKETEXT/POKEDATA to %08lX\n", addr);
rval = 0;
if (access_process_vm(child, addr, &data, sizeof(data), 1)
== sizeof(data))
break;
rval = -EIO;
break;
/* Read/write the word at location ADDR in the registers. */
case PTRACE_PEEKUSR:
case PTRACE_POKEUSR:
pr_debug("PEEKUSR/POKEUSR : 0x%08lx\n", addr);
rval = 0;
if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
/*
* Special requests that don't actually correspond
* to offsets in struct pt_regs.
*/
if (addr == PT_TEXT_ADDR) {
val = child->mm->start_code;
} else if (addr == PT_DATA_ADDR) {
val = child->mm->start_data;
} else if (addr == PT_TEXT_LEN) {
val = child->mm->end_code
- child->mm->start_code;
} else {
rval = -EIO;
}
} else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) {
microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
if (request == PTRACE_PEEKUSR)
val = *reg_addr;
else
*reg_addr = data;
} else
rval = -EIO;
if (rval == 0 && request == PTRACE_PEEKUSR)
rval = put_user(val, (unsigned long *)data);
break;
/* Continue and stop at next (return from) syscall */
case PTRACE_SYSCALL:
pr_debug("PTRACE_SYSCALL\n");
case PTRACE_SINGLESTEP:
pr_debug("PTRACE_SINGLESTEP\n");
/* Restart after a signal. */
case PTRACE_CONT:
pr_debug("PTRACE_CONT\n");
rval = -EIO;
if (!valid_signal(data))
break;
if (request == PTRACE_SYSCALL)
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
else
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->exit_code = data;
pr_debug("wakeup_process\n");
wake_up_process(child);
rval = 0;
break;
/*
* make the child exit. Best I can do is send it a sigkill.
* perhaps it should be put in the status that it wants to
* exit.
*/
case PTRACE_KILL:
pr_debug("PTRACE_KILL\n");
rval = 0;
if (child->exit_state == EXIT_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
wake_up_process(child);
break;
case PTRACE_DETACH: /* detach a process that was attached. */
pr_debug("PTRACE_DETACH\n");
rval = ptrace_detach(child, data);
break;
default:
/* rval = ptrace_request(child, request, addr, data); noMMU */
rval = -EIO;
}
return rval;
}
void ptrace_disable(struct task_struct *child)
{
/* nothing to do */
}
