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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: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Andreas Schwab 2009-05-19 15:38:01 +02:00 committed by Geert Uytterhoeven
parent faa47b4669
commit f195e2bff3
2 changed files with 34 additions and 17 deletions
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6
arch/m68k/kernel/entry.S
View File

@ -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

45
arch/m68k/kernel/ptrace.c
View File

@ -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);