From: Catalin Marinas <catalin.marinas@arm.com>
Date: Thu, 15 Aug 2019 15:44:00 +0000 (+0100)
Subject: arm64: Tighten the PR_{SET, GET}_TAGGED_ADDR_CTRL prctl() unused arguments
X-Git-Tag: v5.4-rc1~100^2~6^9~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3e91ec89f527b9870fe42dcbdb74fd389d123a95;p=platform%2Fkernel%2Flinux-rpi.git

arm64: Tighten the PR_{SET, GET}_TAGGED_ADDR_CTRL prctl() unused arguments

Require that arg{3,4,5} of the PR_{SET,GET}_TAGGED_ADDR_CTRL prctl and
arg2 of the PR_GET_TAGGED_ADDR_CTRL prctl() are zero rather than ignored
for future extensions.

Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---

diff --git a/kernel/sys.c b/kernel/sys.c
index c6c4d53..ec48396 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2499,9 +2499,13 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		error = PAC_RESET_KEYS(me, arg2);
 		break;
 	case PR_SET_TAGGED_ADDR_CTRL:
+		if (arg3 || arg4 || arg5)
+			return -EINVAL;
 		error = SET_TAGGED_ADDR_CTRL(arg2);
 		break;
 	case PR_GET_TAGGED_ADDR_CTRL:
+		if (arg2 || arg3 || arg4 || arg5)
+			return -EINVAL;
 		error = GET_TAGGED_ADDR_CTRL();
 		break;
 	default: