/*
* 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/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/slab.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/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_pt_regs(task);
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_pt_regs(task);
stack += offset;
*(unsigned long *) stack = data;
return 0;
}
static void ptrace_disable_singlestep(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
/*
* Ensure the UBC is not programmed at the next context switch.
*
* Normally this is not needed but there are sequences such as
* singlestep, signal delivery, and continue that leave the
* ubc_pc non-zero leading to spurious SIGTRAPs.
*/
if (child->thread.ubc_pc != 0) {
ubc_usercnt -= 1;
child->thread.ubc_pc = 0;
}
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
ptrace_disable_singlestep(child);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
struct user * dummy = NULL;
int ret;
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 __user *) 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 (!tsk_used_math(child)) {
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 = !!tsk_used_math(child);
else
tmp = 0;
ret = put_user(tmp, (unsigned long __user *)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) {
set_stopped_child_used_math(child);
((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2] = data;
ret = 0;
} else if (addr == (long) &dummy->u_fpvalid) {
conditional_stopped_child_used_math(data, child);
ret = 0;
}
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
ret = -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);
ptrace_disable_singlestep(child);
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->exit_state == EXIT_ZOMBIE) /* already dead */
break;
ptrace_disable_singlestep(child);
child->exit_code = SIGKILL;
wake_up_process(child);
break;
}
case PTRACE_SINGLESTEP: { /* set the trap flag. */
long pc;
struct pt_regs *regs = NULL;
ret = -EIO;
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
if ((child->ptrace & PT_DTRACE) == 0) {
/* Spurious delayed TF traps may occur */
child->ptrace |= PT_DTRACE;
}
pc = get_stack_long(child, (long)®s->pc);
/* Next scheduling will set up UBC */
if (child->thread.ubc_pc == 0)
ubc_usercnt += 1;
child->thread.ubc_pc = pc;
set_tsk_thread_flag(child, TIF_SINGLESTEP);
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;
#ifdef CONFIG_SH_DSP
case PTRACE_GETDSPREGS: {
unsigned long dp;
ret = -EIO;
dp = ((unsigned long) child) + THREAD_SIZE -
sizeof(struct pt_dspregs);
if (*((int *) (dp - 4)) == SR_FD) {
copy_to_user(addr, (void *) dp,
sizeof(struct pt_dspregs));
ret = 0;
}
break;
}
case PTRACE_SETDSPREGS: {
unsigned long dp;
ret = -EIO;
dp = ((unsigned long) child) + THREAD_SIZE -
sizeof(struct pt_dspregs);
if (*((int *) (dp - 4)) == SR_FD) {
copy_from_user((void *) dp, addr,
sizeof(struct pt_dspregs));
ret = 0;
}
break;
}
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
asmlinkage void do_syscall_trace(void)
{
struct task_struct *tsk = current;
if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
!test_thread_flag(TIF_SINGLESTEP))
return;
if (!(tsk->ptrace & PT_PTRACED))
return;
/* 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) &&
!test_thread_flag(TIF_SINGLESTEP) ? 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 (tsk->exit_code) {
send_sig(tsk->exit_code, tsk, 1);
tsk->exit_code = 0;
}
}
