From: Will Deacon <will@kernel.org>
Date: Mon, 29 Jul 2019 10:06:17 +0000 (+0100)
Subject: arm64: compat: Allow single-byte watchpoints on all addresses
X-Git-Tag: v4.4.190~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b90ebda8518042332bb3ee7be4d642378999cf1;p=thirdparty%2Fkernel%2Fstable.git

arm64: compat: Allow single-byte watchpoints on all addresses

commit 849adec41203ac5837c40c2d7e08490ffdef3c2c upstream.

Commit d968d2b801d8 ("ARM: 7497/1: hw_breakpoint: allow single-byte
watchpoints on all addresses") changed the validation requirements for
hardware watchpoints on arch/arm/. Update our compat layer to implement
the same relaxation.

Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index eeebfc3155262..036fbb9598211 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -504,13 +504,14 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
 			/* Aligned */
 			break;
 		case 1:
-			/* Allow single byte watchpoint. */
-			if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
-				break;
 		case 2:
 			/* Allow halfword watchpoints and breakpoints. */
 			if (info->ctrl.len == ARM_BREAKPOINT_LEN_2)
 				break;
+		case 3:
+			/* Allow single byte watchpoint. */
+			if (info->ctrl.len == ARM_BREAKPOINT_LEN_1)
+				break;
 		default:
 			return -EINVAL;
 		}