Commit ee4a3916 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
Browse files

powerpc: fixing ptrace_get_reg to return an error 



Currently ptrace_get_reg returns error as a value
what make impossible to tell whether it is a correct value or error code.

The patch adds a parameter which points to the real return data and
returns an error code.

As get_user_msr() never fails and it is used in multiple places so it has not
been changed by this patch.

Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
parent 3cc33d50

arch/powerpc/include/asm/ptrace.h

+2 −1
Original line number Diff line number Diff line
@@ -92,7 +92,8 @@ static inline long regs_return_value(struct pt_regs *regs) 
	} while(0)



struct task_struct;

extern unsigned long ptrace_get_reg(struct task_struct *task, int regno);

extern int ptrace_get_reg(struct task_struct *task, int regno,

			  unsigned long *data);

extern int ptrace_put_reg(struct task_struct *task, int regno,

			  unsigned long data);

arch/powerpc/kernel/ptrace.c

+18 −11
Original line number Diff line number Diff line
@@ -180,9 +180,10 @@ static int set_user_msr(struct task_struct *task, unsigned long msr) 
}



#ifdef CONFIG_PPC64

static unsigned long get_user_dscr(struct task_struct *task)

static int get_user_dscr(struct task_struct *task, unsigned long *data)

{

	return task->thread.dscr;

	*data = task->thread.dscr;

	return 0;

}



static int set_user_dscr(struct task_struct *task, unsigned long dscr)
@@ -192,7 +193,7 @@ static int set_user_dscr(struct task_struct *task, unsigned long dscr) 
	return 0;

}

#else

static unsigned long get_user_dscr(struct task_struct *task)

static int get_user_dscr(struct task_struct *task, unsigned long *data)

{

	return -EIO;

}
@@ -216,19 +217,23 @@ static int set_user_trap(struct task_struct *task, unsigned long trap) 
/*

 * Get contents of register REGNO in task TASK.

 */

unsigned long ptrace_get_reg(struct task_struct *task, int regno)

int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data)

{

	if (task->thread.regs == NULL)

	if ((task->thread.regs == NULL) || !data)

		return -EIO;



	if (regno == PT_MSR)

		return get_user_msr(task);

	if (regno == PT_MSR) {

		*data = get_user_msr(task);

		return 0;

	}



	if (regno == PT_DSCR)

		return get_user_dscr(task);

		return get_user_dscr(task, data);



	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))

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

	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) {

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

		return 0;

	}



	return -EIO;

}
@@ -1560,7 +1565,9 @@ long arch_ptrace(struct task_struct *child, long request, 


		CHECK_FULL_REGS(child->thread.regs);

		if (index < PT_FPR0) {

			tmp = ptrace_get_reg(child, (int) index);

			ret = ptrace_get_reg(child, (int) index, &tmp);

			if (ret)

				break;

		} else {

			unsigned int fpidx = index - PT_FPR0;

arch/powerpc/kernel/ptrace32.c

+12 −3
Original line number Diff line number Diff line
@@ -95,7 +95,9 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 


		CHECK_FULL_REGS(child->thread.regs);

		if (index < PT_FPR0) {

			tmp = ptrace_get_reg(child, index);

			ret = ptrace_get_reg(child, index, &tmp);

			if (ret)

				break;

		} else {

			flush_fp_to_thread(child);

			/*
@@ -148,7 +150,11 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 
			tmp = ((u64 *)child->thread.fpr)

				[FPRINDEX_3264(numReg)];

		} else { /* register within PT_REGS struct */

			tmp = ptrace_get_reg(child, numReg);

			unsigned long tmp2;

			ret = ptrace_get_reg(child, numReg, &tmp2);

			if (ret)

				break;

			tmp = tmp2;

		} 

		reg32bits = ((u32*)&tmp)[part];

		ret = put_user(reg32bits, (u32 __user *)data);
@@ -232,7 +238,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 
			break;

		CHECK_FULL_REGS(child->thread.regs);

		if (numReg < PT_FPR0) {

			unsigned long freg = ptrace_get_reg(child, numReg);

			unsigned long freg;

			ret = ptrace_get_reg(child, numReg, &freg);

			if (ret)

				break;

			if (index % 2)

				freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);

			else

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