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[POWERPC] ptrace accessors for special regs MSR and TRAP

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This isolates the ptrace code for the special-case registers msr and trap
from the ptrace-layout dispatch code.  This should inline away completely.
It cleanly separates the low-level machine magic that has to be done for
deep reasons, from the superficial details of the ptrace interface.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Roland McGrath 2007-12-20 03:57:51 -08:00 committed by Paul Mackerras
parent a4e4b175b6
commit 26f7713020
1 changed files with 30 additions and 15 deletions
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45
arch/powerpc/kernel/ptrace.c
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@ -60,20 +60,38 @@
#define PT_MAX_PUT_REG PT_CCR
#endif
static unsigned long get_user_msr(struct task_struct *task)
{
return task->thread.regs->msr | task->thread.fpexc_mode;
}
static int set_user_msr(struct task_struct *task, unsigned long msr)
{
task->thread.regs->msr &= ~MSR_DEBUGCHANGE;
task->thread.regs->msr |= msr & MSR_DEBUGCHANGE;
return 0;
}
/*
* We prevent mucking around with the reserved area of trap
* which are used internally by the kernel.
*/
static int set_user_trap(struct task_struct *task, unsigned long trap)
{
task->thread.regs->trap = trap & 0xfff0;
return 0;
}
/*
* Get contents of register REGNO in task TASK.
*/
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
unsigned long tmp = 0;
if (task->thread.regs == NULL)
return -EIO;
if (regno == PT_MSR) {
tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
return tmp | task->thread.fpexc_mode;
}
if (regno == PT_MSR)
return get_user_msr(task);
if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
return ((unsigned long *)task->thread.regs)[regno];
@ -89,15 +107,12 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
if (task->thread.regs == NULL)
return -EIO;
if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
if (regno == PT_MSR)
data = (data & MSR_DEBUGCHANGE)
| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
/* We prevent mucking around with the reserved area of trap
* which are used internally by the kernel
*/
if (regno == PT_TRAP)
data &= 0xfff0;
if (regno == PT_MSR)
return set_user_msr(task, data);
if (regno == PT_TRAP)
return set_user_trap(task, data);
if (regno <= PT_MAX_PUT_REG) {
((unsigned long *)task->thread.regs)[regno] = data;
return 0;
}