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/*
* 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.
*
* 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
* Copyright (C) 2000 Ulf Carlsson
*
* At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
* binaries.
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/user.h>
#include <asm/mipsregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
/*
* 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.. */
}
/*
* Tracing a 32-bit process with a 64-bit strace and vice versa will not
* work. I don't know how to fix this.
*/
asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
{
struct task_struct *child;
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 != current)
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 int 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 int *) (unsigned long) data);
break;
}
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
unsigned int tmp;
regs = (struct pt_regs *) ((unsigned long) child +
KERNEL_STACK_SIZE - 32 - sizeof(struct pt_regs));
ret = 0;
switch (addr) {
case 0 ... 31:
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
if (child->used_math) {
unsigned long *fregs =
(void *) child->thread.fpu.hard.fp_regs;
#ifndef CONFIG_SMP
if (last_task_used_math == child) {
set_cp0_status(ST0_CU1, ST0_CU1);
save_fp(child);
set_cp0_status(ST0_CU1, 0);
last_task_used_math = NULL;
}
#endif
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers.
*/
if (addr & 1)
tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
else
tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
} else {
tmp = -EIO;
}
break;
case PC:
tmp = regs->cp0_epc;
break;
case CAUSE:
tmp = regs->cp0_cause;
break;
case BADVADDR:
tmp = regs->cp0_badvaddr;
break;
case MMHI:
tmp = regs->hi;
break;
case MMLO:
tmp = regs->lo;
break;
case FPC_CSR:
tmp = child->thread.fpu.hard.control;
break;
case FPC_EIR: { /* implementation / version register */
unsigned int flags;
__save_flags(flags);
set_cp0_status(ST0_CU1, ST0_CU1);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
__restore_flags(flags);
break;
}
default:
tmp = 0;
ret = -EIO;
goto out_tsk;
}
ret = put_user(tmp, (unsigned *) (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: {
struct pt_regs *regs;
ret = 0;
regs = (struct pt_regs *) ((unsigned long) child +
KERNEL_STACK_SIZE - 32 - sizeof(struct pt_regs));
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
break;
case FPR_BASE ... FPR_BASE + 31: {
unsigned long *fregs =
(void *) child->thread.fpu.hard.fp_regs;
if (child->used_math) {
#ifndef CONFIG_SMP
if (last_task_used_math == child) {
set_cp0_status(ST0_CU1, ST0_CU1);
save_fp(child);
set_cp0_status(ST0_CU1, 0);
last_task_used_math = NULL;
regs->cp0_status &= ~ST0_CU1;
}
#endif
} else {
/* FP not yet used */
memset(&child->thread.fpu.hard, ~0,
sizeof(child->thread.fpu.hard));
child->thread.fpu.hard.control = 0;
}
/*
* The odd registers are actually the high order bits
* of the values stored in the even registers - unless
* we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long) data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
}
break;
}
case PC:
regs->cp0_epc = data;
break;
case MMHI:
regs->hi = data;
break;
case MMLO:
regs->lo = data;
break;
case FPC_CSR:
child->thread.fpu.hard.control = data;
break;
default:
/* The rest are not allowed. */
ret = -EIO;
break;
}
goto out;
}
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
ret = -EIO;
if ((unsigned int) 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: {
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
wake_up_process(child);
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 int sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
int ret;
lock_kernel();
#if 0
printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
(int) request, (int) pid, (unsigned long) addr,
(unsigned long) data);
#endif
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;
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 != current)
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: {
struct pt_regs *regs;
unsigned long tmp;
regs = (struct pt_regs *) ((unsigned long) child +
KERNEL_STACK_SIZE - 32 - sizeof(struct pt_regs));
ret = 0;
switch (addr) {
case 0 ... 31:
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
if (child->used_math) {
unsigned long long *fregs
= (unsigned long long *)
&child->thread.fpu.hard.fp_regs[0];
#ifndef CONFIG_SMP
if (last_task_used_math == child) {
set_cp0_status(ST0_CU1, ST0_CU1);
save_fp(child);
set_cp0_status(ST0_CU1, 0);
last_task_used_math = NULL;
}
#endif
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers.
*/
if (addr & 1)
tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
else
tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
} else {
tmp = -EIO;
}
break;
case PC:
tmp = regs->cp0_epc;
break;
case CAUSE:
tmp = regs->cp0_cause;
break;
case BADVADDR:
tmp = regs->cp0_badvaddr;
break;
case MMHI:
tmp = regs->hi;
break;
case MMLO:
tmp = regs->lo;
break;
case FPC_CSR:
tmp = child->thread.fpu.hard.control;
break;
case FPC_EIR: { /* implementation / version register */
unsigned int flags;
__save_flags(flags);
set_cp0_status(ST0_CU1, ST0_CU1);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
__restore_flags(flags);
break;
}
default:
tmp = 0;
ret = -EIO;
goto out_tsk;
}
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: {
struct pt_regs *regs;
ret = 0;
regs = (struct pt_regs *) ((unsigned long) child +
KERNEL_STACK_SIZE - 32 - sizeof(struct pt_regs));
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
break;
case FPR_BASE ... FPR_BASE + 31: {
unsigned long *fregs =
(void *) child->thread.fpu.hard.fp_regs;
if (child->used_math) {
#ifndef CONFIG_SMP
if (last_task_used_math == child) {
set_cp0_status(ST0_CU1, ST0_CU1);
save_fp(child);
set_cp0_status(ST0_CU1, 0);
last_task_used_math = NULL;
regs->cp0_status &= ~ST0_CU1;
}
#endif
} else {
/* FP not yet used */
memset(&child->thread.fpu.hard, ~0,
sizeof(child->thread.fpu.hard));
child->thread.fpu.hard.control = 0;
}
/*
* The odd registers are actually the high order bits
* of the values stored in the even registers - unless
* we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long) data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
}
break;
}
case PC:
regs->cp0_epc = data;
break;
case MMHI:
regs->hi = data;
break;
case MMLO:
regs->lo = data;
break;
case FPC_CSR:
child->thread.fpu.hard.control = data;
break;
default:
/* The rest are not allowed. */
ret = -EIO;
break;
}
goto out;
}
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: {
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
wake_up_process(child);
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)
{
if ((current->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 */
current->exit_code = SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
? 0x80 : 0);
current->state = TASK_STOPPED;
notify_parent(current, 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 (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
}
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