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

BugLink: https://bugs.launchpad.net/bugs/1845038

commit 849adec4 upstream.

Commit d968d2b8 ("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>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

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;
 		}