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Commit 6a2e5e52 authored by Matthew Leach's avatar Matthew Leach Committed by Catalin Marinas
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arm64: ptrace: fix compat registes get/set to be endian clean 



On a BE system the wrong half of the X registers is retrieved/written
when attempting to get/set the value of aarch32 registers through
ptrace.

Ensure that types are the correct width so that the relevant
casting occurs.

Signed-off-by: default avatarMatthew Leach <matthew.leach@arm.com>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b3bf6aa7

arch/arm64/kernel/ptrace.c

+19 −21
Original line number Diff line number Diff line
@@ -636,28 +636,27 @@ static int compat_gpr_get(struct task_struct *target, 


	for (i = 0; i < num_regs; ++i) {

		unsigned int idx = start + i;

		void *reg;

		compat_ulong_t reg;



		switch (idx) {

		case 15:

			reg = (void *)&task_pt_regs(target)->pc;

			reg = task_pt_regs(target)->pc;

			break;

		case 16:

			reg = (void *)&task_pt_regs(target)->pstate;

			reg = task_pt_regs(target)->pstate;

			break;

		case 17:

			reg = (void *)&task_pt_regs(target)->orig_x0;

			reg = task_pt_regs(target)->orig_x0;

			break;

		default:

			reg = (void *)&task_pt_regs(target)->regs[idx];

			reg = task_pt_regs(target)->regs[idx];

		}



		ret = copy_to_user(ubuf, reg, sizeof(compat_ulong_t));



		ret = copy_to_user(ubuf, &reg, sizeof(reg));

		if (ret)

			break;

		else

			ubuf += sizeof(compat_ulong_t);



		ubuf += sizeof(reg);

	}



	return ret;
@@ -685,28 +684,28 @@ static int compat_gpr_set(struct task_struct *target, 


	for (i = 0; i < num_regs; ++i) {

		unsigned int idx = start + i;

		void *reg;

		compat_ulong_t reg;



		ret = copy_from_user(&reg, ubuf, sizeof(reg));

		if (ret)

			return ret;



		ubuf += sizeof(reg);



		switch (idx) {

		case 15:

			reg = (void *)&newregs.pc;

			newregs.pc = reg;

			break;

		case 16:

			reg = (void *)&newregs.pstate;

			newregs.pstate = reg;

			break;

		case 17:

			reg = (void *)&newregs.orig_x0;

			newregs.orig_x0 = reg;

			break;

		default:

			reg = (void *)&newregs.regs[idx];

			newregs.regs[idx] = reg;

		}



		ret = copy_from_user(reg, ubuf, sizeof(compat_ulong_t));



		if (ret)

			goto out;

		else

			ubuf += sizeof(compat_ulong_t);

	}



	if (valid_user_regs(&newregs.user_regs))
@@ -714,7 +713,6 @@ static int compat_gpr_set(struct task_struct *target, 
	else

		ret = -EINVAL;



out:

	return ret;

}