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/* $Id: ptrace.c,v 1.13 2001/10/01 02:21:50 gniibe Exp $
*
* linux/arch/sh/kernel/ptrace.c
*
* Original x86 implementation:
* By Ross Biro 1/23/92
* edited by Linus Torvalds
*
* SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* This routine will get a word off of the process kernel stack.
*/
static inline int get_stack_long(struct task_struct *task, int offset)
{
unsigned char *stack;
stack = (unsigned char *)task + THREAD_SIZE - sizeof(struct pt_regs);
stack += offset;
return (*((int *)stack));
}
/*
* This routine will put a word on the process kernel stack.
*/
static inline int put_stack_long(struct task_struct *task, int offset,
unsigned long data)
{
unsigned char *stack;
stack = (unsigned char *)task + THREAD_SIZE - sizeof(struct pt_regs);
stack += offset;
*(unsigned long *) stack = data;
return 0;
}
static void
compute_next_pc(struct pt_regs *regs, unsigned short inst,
unsigned long *pc1, unsigned long *pc2)
{
int nib[4]
= { (inst >> 12) & 0xf,
(inst >> 8) & 0xf,
(inst >> 4) & 0xf,
inst & 0xf};
/* bra & bsr */
if (nib[0] == 0xa || nib[0] == 0xb) {
*pc1 = regs->pc + 4 + ((short) ((inst & 0xfff) << 4) >> 3);
*pc2 = (unsigned long) -1;
return;
}
/* bt & bf */
if (nib[0] == 0x8 && (nib[1] == 0x9 || nib[1] == 0xb)) {
*pc1 = regs->pc + 4 + ((char) (inst & 0xff) << 1);
*pc2 = regs->pc + 2;
return;
}
/* bt/s & bf/s */
if (nib[0] == 0x8 && (nib[1] == 0xd || nib[1] == 0xf)) {
*pc1 = regs->pc + 4 + ((char) (inst & 0xff) << 1);
*pc2 = regs->pc + 4;
return;
}
/* jmp & jsr */
if (nib[0] == 0x4 && nib[3] == 0xb
&& (nib[2] == 0x0 || nib[2] == 0x2)) {
*pc1 = regs->regs[nib[1]];
*pc2 = (unsigned long) -1;
return;
}
/* braf & bsrf */
if (nib[0] == 0x0 && nib[3] == 0x3
&& (nib[2] == 0x0 || nib[2] == 0x2)) {
*pc1 = regs->pc + 4 + regs->regs[nib[1]];
*pc2 = (unsigned long) -1;
return;
}
if (inst == 0x000b) {
*pc1 = regs->pr;
*pc2 = (unsigned long) -1;
return;
}
*pc1 = regs->pc + 2;
*pc2 = (unsigned long) -1;
return;
}
/* Tracing by user break controller. */
static void
ubc_set_tracing(int asid, unsigned long nextpc1, unsigned nextpc2)
{
ctrl_outl(nextpc1, UBC_BARA);
ctrl_outb(asid, UBC_BASRA);
if(UBC_TYPE_SH7729){
ctrl_outl(0x0fff, UBC_BAMRA);
ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
}else{
ctrl_outb(BAMR_12, UBC_BAMRA);
ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
}
if (nextpc2 != (unsigned long) -1) {
ctrl_outl(nextpc2, UBC_BARB);
ctrl_outb(asid, UBC_BASRB);
if(UBC_TYPE_SH7729){
ctrl_outl(0x0fff, UBC_BAMRB);
ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRB);
}else{
ctrl_outb(BAMR_12, UBC_BAMRB);
ctrl_outw(BBR_INST | BBR_READ, UBC_BBRB);
}
}
if(UBC_TYPE_SH7729)
ctrl_outl(BRCR_PCBA | BRCR_PCBB | BRCR_PCTE, UBC_BRCR);
else
ctrl_outw(BRCR_PCBA | BRCR_PCBB, UBC_BRCR);
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
/* nothing to do.. */
}
asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child, *tsk = current;
struct user * dummy = NULL;
int ret;
lock_kernel();
ret = -EPERM;
if (request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
ret = 0;
goto out;
}
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* you may not mess with init */
goto out_tsk;
if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);
goto out_tsk;
}
ret = -ESRCH;
if (!(child->ptrace & PT_PTRACED))
goto out_tsk;
if (child->state != TASK_STOPPED) {
if (request != PTRACE_KILL)
goto out_tsk;
}
if (child->p_pptr != tsk)
goto out_tsk;
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
int copied;
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
break;
ret = put_user(tmp,(unsigned long *) data);
break;
}
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
tmp = get_stack_long(child, addr);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
if (!child->used_math) {
if (addr == (long)&dummy->fpu.fpscr)
tmp = FPSCR_INIT;
else
tmp = 0;
} else
tmp = ((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2];
} else if (addr == (long) &dummy->u_fpvalid)
tmp = child->used_math;
else
tmp = 0;
ret = put_user(tmp, (unsigned long *)data);
break;
}
/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = 0;
if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
break;
ret = -EIO;
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
ret = put_stack_long(child, addr, data);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
child->used_math = 1;
((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2] = data;
ret = 0;
} else if (addr == (long) &dummy->u_fpvalid) {
child->used_math = data?1:0;
ret = 0;
}
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
ret = -EIO;
if ((unsigned long) data > _NSIG)
break;
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
wake_up_process(child);
ret = 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: {
ret = 0;
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
wake_up_process(child);
break;
}
case PTRACE_SINGLESTEP: { /* set the trap flag. */
long tmp, pc;
struct pt_regs *dummy = NULL;
struct pt_regs *regs;
unsigned long nextpc1, nextpc2;
unsigned short insn;
ret = -EIO;
if ((unsigned long) data > _NSIG)
break;
child->ptrace &= ~PT_TRACESYS;
if ((child->ptrace & PT_DTRACE) == 0) {
/* Spurious delayed TF traps may occur */
child->ptrace |= PT_DTRACE;
}
/* Compute next pc. */
pc = get_stack_long(child, (long)&dummy->pc);
regs = (struct pt_regs *)((unsigned long)child + THREAD_SIZE - sizeof(struct pt_regs));
if (access_process_vm(child, pc&~3, &tmp, sizeof(tmp), 0) != sizeof(tmp))
break;
#ifdef __LITTLE_ENDIAN__
if (pc & 3)
insn = tmp >> 16;
else
insn = tmp & 0xffff;
#else
if (pc & 3)
insn = tmp & 0xffff;
else
insn = tmp >> 16;
#endif
compute_next_pc (regs, insn, &nextpc1, &nextpc2);
if (nextpc1 & 0x80000000)
break;
if (nextpc2 != (unsigned long) -1 && (nextpc2 & 0x80000000))
break;
ubc_set_tracing(child->mm->context & MMU_CONTEXT_ASID_MASK,
nextpc1, nextpc2);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
}
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
case PTRACE_SETOPTIONS: {
if (data & PTRACE_O_TRACESYSGOOD)
child->ptrace |= PT_TRACESYSGOOD;
else
child->ptrace &= ~PT_TRACESYSGOOD;
ret = 0;
break;
}
default:
ret = -EIO;
break;
}
out_tsk:
free_task_struct(child);
out:
unlock_kernel();
return ret;
}
asmlinkage void syscall_trace(void)
{
struct task_struct *tsk = current;
if ((tsk->ptrace & (PT_PTRACED|PT_TRACESYS))
!= (PT_PTRACED|PT_TRACESYS))
return;
/* the 0x80 provides a way for the tracing parent to distinguish
between a syscall stop and SIGTRAP delivery */
tsk->exit_code = SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
? 0x80 : 0);
tsk->state = TASK_STOPPED;
notify_parent(tsk, SIGCHLD);
schedule();
/*
* 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 (tsk->exit_code) {
send_sig(tsk->exit_code, tsk, 1);
tsk->exit_code = 0;
}
}
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