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; }