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[PATCH] m68k: sys_ptrace cleanup
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- 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: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Roman Zippel authored and Linus Torvalds committed Sep 5, 2005
1 parent b3319f5 commit 69f447c
Showing 1 changed file with 64 additions and 111 deletions.
175 changes: 64 additions & 111 deletions arch/m68k/kernel/ptrace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -103,135 +103,119 @@ 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;
}

ret = -EPERM;
if (pid == 1) /* you may not mess with init */
/* you may not mess with init */
if (unlikely(pid == 1)) {
ret = -EPERM;
goto out_tsk;
}

if (request == PTRACE_ATTACH) {
ret = ptrace_attach(child);
goto out_tsk;
}

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
*/
Expand All @@ -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);
Expand All @@ -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;
Expand All @@ -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);
Expand All @@ -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)
Expand Down

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