FAILED: patch "[PATCH] arm64: compat: Allow single-byte watchpoints on all addresses" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 849adec41203ac5837c40c2d7e08490ffdef3c2c Mon Sep 17 00:00:00 2001
From: Will Deacon <will@kernel.org>
Date: Mon, 29 Jul 2019 11:06:17 +0100
Subject: [PATCH] arm64: compat: Allow single-byte watchpoints on all addresses

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>

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index dceb84520948..67b3bae50b92 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -536,13 +536,14 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 			/* Aligned */
 			break;
 		case 1:
-			/* Allow single byte watchpoint. */
-			if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
-				break;
 		case 2:
 			/* Allow halfword watchpoints and breakpoints. */
 			if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
 				break;
+		case 3:
+			/* Allow single byte watchpoint. */
+			if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
+				break;
 		default:
 			return -EINVAL;
 		}