arch/sh/kernel/ptrace.c - maze/linux - Git at Google

 /*
  * 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 *) 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 *)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 *dummy = 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)&dummy->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;
 	}
 }
	/*
	* 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 *) 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 *)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 *dummy = 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)&dummy->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;
	}
	}