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Commit 69f447cf authored by Roman Zippel's avatar Roman Zippel Committed by Linus Torvalds
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[PATCH] m68k: sys_ptrace cleanup 



- create helper function singlestep_disable()
- move variable definitions to the top of the function
- use "out_eio" label as common error destination
- don't clear failure value for PTRACE_SETREGS/PTRACE_GETREGS

Signed-off-by: default avatarRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b3319f50

arch/m68k/kernel/ptrace.c

+64 −111
Original line number Diff line number Diff line
@@ -103,48 +103,56 @@ static inline int put_reg(struct task_struct *task, int regno, 
}



/*

 * Called by kernel/ptrace.c when detaching..

 *

 * Make sure the single step bit is not set.

 */

void ptrace_disable(struct task_struct *child)

static inline void singlestep_disable(struct task_struct *child)

{

	unsigned long tmp;

	/* make sure the single step bit is not set. */

	tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);

	unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);

	put_reg(child, PT_SR, tmp);

	child->thread.work.delayed_trace = 0;

}



/*

 * Called by kernel/ptrace.c when detaching..

 */

void ptrace_disable(struct task_struct *child)

{

	singlestep_disable(child);

	child->thread.work.syscall_trace = 0;

}



asmlinkage int sys_ptrace(long request, long pid, long addr, long data)

{

	struct task_struct *child;

	int ret;

	unsigned long tmp;

	int i, ret = 0;



	lock_kernel();

	ret = -EPERM;

	if (request == PTRACE_TRACEME) {

		/* are we already being traced? */

		if (current->ptrace & PT_PTRACED)

		if (current->ptrace & PT_PTRACED) {

			ret = -EPERM;

			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)

	if (unlikely(!child)) {

		ret = -ESRCH;

		goto out;

	}



	/* you may not mess with init */

	if (unlikely(pid == 1)) {

		ret = -EPERM;

	if (pid == 1)		/* you may not mess with init */

		goto out_tsk;

	}



	if (request == PTRACE_ATTACH) {

		ret = ptrace_attach(child);
@@ -152,86 +160,62 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) 
	}



	ret = ptrace_check_attach(child, request == PTRACE_KILL);

	if (ret < 0)

	if (ret)

		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;

	case PTRACE_PEEKDATA:

		i = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);

		if (i != sizeof(tmp))

			goto out_eio;

		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;

	case PTRACE_PEEKUSR:

		if (addr & 3)

			goto out_eio;

		addr >>= 2;	/* temporary hack. */



		tmp = 0;  /* Default return condition */

		addr = addr >> 2; /* temporary hack. */

		ret = -EIO;

		if (addr < 19) {

		if (addr >= 0 && addr < 19) {

			tmp = get_reg(child, addr);

			if (addr == PT_SR)

				tmp >>= 16;

		} else if (addr >= 21 && addr < 49) {

			tmp = child->thread.fp[addr - 21];

#ifdef CONFIG_M68KFPU_EMU

			/* Convert internal fpu reg representation

			 * into long double format

			 */

			if (FPU_IS_EMU && (addr < 45) && !(addr % 3))

				tmp = ((tmp & 0xffff0000) << 15) |

				      ((tmp & 0x0000ffff) << 16);

#endif

		} else

			break;

		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;

		if (access_process_vm(child, addr, &data, sizeof(data), 1) != sizeof(data))

			goto out_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;



		addr = addr >> 2; /* temporary hack. */

		if (addr & 3)

			goto out_eio;

		addr >>= 2;	/* temporary hack. */



		if (addr == PT_SR) {

			data &= SR_MASK;

			data <<= 16;

			data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);

		}

		if (addr < 19) {

		} else if (addr >= 0 && addr < 19) {

			if (put_reg(child, addr, data))

				break;

			ret = 0;

			break;

		}

		if (addr >= 21 && addr < 48) {

#ifdef CONFIG_M68KFPU_EMU

				goto out_eio;

		} else if (addr >= 21 && addr < 48) {

			/* Convert long double format

			 * into internal fpu reg representation

			 */
@@ -240,60 +224,42 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) 
				data = (data & 0xffff0000) |

				       ((data & 0x0000ffff) >> 1);

			}

#endif

			child->thread.fp[addr - 21] = data;

			ret = 0;

		}

		} else

			goto out_eio;

		break;



	case PTRACE_SYSCALL:	/* continue and stop at next (return from) syscall */

	case PTRACE_CONT: {	/* restart after signal. */

		long tmp;



		ret = -EIO;

	case PTRACE_CONT:	/* restart after signal. */

		if (!valid_signal(data))

			break;

		if (request == PTRACE_SYSCALL) {

			goto out_eio;



		if (request == PTRACE_SYSCALL)

			child->thread.work.syscall_trace = ~0;

		} else {

		else

			child->thread.work.syscall_trace = 0;

		}

		child->exit_code = data;

		/* make sure the single step bit is not set. */

		tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);

		put_reg(child, PT_SR, tmp);

		child->thread.work.delayed_trace = 0;

		singlestep_disable(child);

		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: {

		long tmp;



		ret = 0;

	case PTRACE_KILL:

		if (child->exit_state == EXIT_ZOMBIE) /* already dead */

			break;

		child->exit_code = SIGKILL;

		/* make sure the single step bit is not set. */

		tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);

		put_reg(child, PT_SR, tmp);

		child->thread.work.delayed_trace = 0;

		singlestep_disable(child);

		wake_up_process(child);

		break;

	}



	case PTRACE_SINGLESTEP: {  /* set the trap flag. */

		long tmp;



		ret = -EIO;

	case PTRACE_SINGLESTEP:	/* set the trap flag. */

		if (!valid_signal(data))

			break;

			goto out_eio;



		child->thread.work.syscall_trace = 0;

		tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);

		put_reg(child, PT_SR, tmp);
@@ -302,39 +268,29 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) 
		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_GETREGS: { /* Get all gp regs from the child. */

		int i;

		unsigned long tmp;

	case PTRACE_GETREGS:	/* Get all gp regs from the child. */

		for (i = 0; i < 19; i++) {

			tmp = get_reg(child, i);

			if (i == PT_SR)

				tmp >>= 16;

			if (put_user(tmp, (unsigned long *)data)) {

				ret = -EFAULT;

			ret = put_user(tmp, (unsigned long *)data);

			if (ret)

				break;

			}

			data += sizeof(long);

		}

		ret = 0;

		break;

	}



	case PTRACE_SETREGS: { /* Set all gp regs in the child. */

		int i;

		unsigned long tmp;

	case PTRACE_SETREGS:	/* Set all gp regs in the child. */

		for (i = 0; i < 19; i++) {

			if (get_user(tmp, (unsigned long *)data)) {

				ret = -EFAULT;

			ret = get_user(tmp, (unsigned long *)data);

			if (ret)

				break;

			}

			if (i == PT_SR) {

				tmp &= SR_MASK;

				tmp <<= 16;
@@ -343,25 +299,19 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) 
			put_reg(child, i, tmp);

			data += sizeof(long);

		}

		ret = 0;

		break;

	}



	case PTRACE_GETFPREGS: { /* Get the child FPU state. */

		ret = 0;

	case PTRACE_GETFPREGS:	/* Get the child FPU state. */

		if (copy_to_user((void *)data, &child->thread.fp,

				 sizeof(struct user_m68kfp_struct)))

			ret = -EFAULT;

		break;

	}



	case PTRACE_SETFPREGS: { /* Set the child FPU state. */

		ret = 0;

	case PTRACE_SETFPREGS:	/* Set the child FPU state. */

		if (copy_from_user(&child->thread.fp, (void *)data,

				   sizeof(struct user_m68kfp_struct)))

			ret = -EFAULT;

		break;

	}



	default:

		ret = ptrace_request(child, request, addr, data);
@@ -372,6 +322,9 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data) 
out:

	unlock_kernel();

	return ret;

out_eio:

	ret = -EIO;

	goto out_tsk;

}



asmlinkage void syscall_trace(void)