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Commit f195e2bf authored by Andreas Schwab's avatar Andreas Schwab Committed by Geert Uytterhoeven
Browse files

m68k: ptrace fixes 



This fixes the following issues in ptrace:

- when single stepping into the signal handler stop at the first insn of
  the handler
- handle non-zero stkadj when accessing pc and sr in ptregs
- correctly handle PT_SR in PTRACE_POKEUSR
- report -EIO when trying to read unknown offset in PTRACE_PEEKUSR

Additionally, the handling of the special case that PT_SR accesses a 16
bit word instead of a 32 bit word has been moved into get_reg/put_reg.

Signed-off-by: default avatarAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent faa47b46

arch/m68k/kernel/entry.S

+5 −1
Original line number Diff line number Diff line
@@ -179,7 +179,11 @@ do_signal_return: 
	addql	#8,%sp

	RESTORE_SWITCH_STACK

	addql	#4,%sp

	jbra	resume_userspace

	tstl	%d0

	jeq	resume_userspace

	| when single stepping into handler stop at the first insn

	btst	#6,%curptr@(TASK_INFO+TINFO_FLAGS+2)

	jeq	resume_userspace



do_delayed_trace:

	bclr	#7,%sp@(PT_OFF_SR)	| clear trace bit in SR

arch/m68k/kernel/ptrace.c

+29 −16
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ 
/* Mapping from PT_xxx to the stack offset at which the register is

   saved.  Notice that usp has no stack-slot and needs to be treated

   specially (see get_reg/put_reg below). */

static int regoff[] = {

static const int regoff[] = {

	[0]	= PT_REG(d1),

	[1]	= PT_REG(d2),

	[2]	= PT_REG(d3),
@@ -81,6 +81,14 @@ static inline long get_reg(struct task_struct *task, int regno) 
		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);

	else

		return 0;

	/* Need to take stkadj into account. */

	if (regno == PT_SR || regno == PT_PC) {

		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));

		addr = (unsigned long *) ((unsigned long)addr + stkadj);

		/* The sr is actually a 16 bit register.  */

		if (regno == PT_SR)

			return *(unsigned short *)addr;

	}

	return *addr;

}
@@ -98,6 +106,16 @@ static inline int put_reg(struct task_struct *task, int regno, 
		addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);

	else

		return -1;

	/* Need to take stkadj into account. */

	if (regno == PT_SR || regno == PT_PC) {

		long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));

		addr = (unsigned long *) ((unsigned long)addr + stkadj);

		/* The sr is actually a 16 bit register.  */

		if (regno == PT_SR) {

			*(unsigned short *)addr = data;

			return 0;

		}

	}

	*addr = data;

	return 0;

}
@@ -107,7 +125,7 @@ static inline int put_reg(struct task_struct *task, int regno, 
 */

static inline void singlestep_disable(struct task_struct *child)

{

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

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

	put_reg(child, PT_SR, tmp);

	clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);

}
@@ -122,15 +140,15 @@ void ptrace_disable(struct task_struct *child) 


void user_enable_single_step(struct task_struct *child)

{

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

	put_reg(child, PT_SR, tmp | (T1_BIT << 16));

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

	put_reg(child, PT_SR, tmp | T1_BIT);

	set_tsk_thread_flag(child, TIF_DELAYED_TRACE);

}



void user_enable_block_step(struct task_struct *child)

{

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

	put_reg(child, PT_SR, tmp | (T0_BIT << 16));

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

	put_reg(child, PT_SR, tmp | T0_BIT);

}



void user_disable_single_step(struct task_struct *child)
@@ -152,8 +170,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 


		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];

			/* Convert internal fpu reg representation
@@ -163,7 +179,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
				tmp = ((tmp & 0xffff0000) << 15) |

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

		} else

			break;

			goto out_eio;

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

		break;
@@ -174,9 +190,9 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 


		if (addr == PT_SR) {

			data &= SR_MASK;

			data <<= 16;

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

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

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

		}

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

			if (put_reg(child, addr, data))

				goto out_eio;

		} else if (addr >= 21 && addr < 48) {
@@ -196,8 +212,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
	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;

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

			if (ret)

				break;
@@ -212,8 +226,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
				break;

			if (i == PT_SR) {

				tmp &= SR_MASK;

				tmp <<= 16;

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

				tmp |= get_reg(child, PT_SR) & ~SR_MASK;

			}

			put_reg(child, i, tmp);

			data += sizeof(long);