[PATCH 4.4 65/78] arm64: compat: Allow single-byte watchpoints on all addresses

Greg Kroah-Hartman
2019-08-22T17:46:23Z

From: Will Deacon <will@kernel.org>

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>

---
arch/arm64/kernel/hw_breakpoint.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -504,13 +504,14 @@ int arch_validate_hwbkpt_settings(struct
/* 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;
}