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Commit 26f77130 authored by Roland McGrath's avatar Roland McGrath Committed by Paul Mackerras
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[POWERPC] ptrace accessors for special regs MSR and TRAP 



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: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent a4e4b175

arch/powerpc/kernel/ptrace.c

+30 −15
Original line number Diff line number Diff line
@@ -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

		 */

		return set_user_msr(task, data);

	if (regno == PT_TRAP)

			data &= 0xfff0;

		return set_user_trap(task, data);



	if (regno <= PT_MAX_PUT_REG) {

		((unsigned long *)task->thread.regs)[regno] = data;

		return 0;

	}