On Fri, Jul 26, 2019 at 01:10:57PM +0100, Mark Rutland wrote:
On Fri, Jul 26, 2019 at 01:27:16PM +0200, Anders Roxell wrote:
When fall-through warnings was enabled by default, commit d93512ef0f0e ("Makefile: Globally enable fall-through warning"), the following warnings was starting to show up:
../arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’: ../arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1) ^ ../arch/arm64/kernel/hw_breakpoint.c:542:3: note: here case 2: ^~~~ ../arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2) ^ ../arch/arm64/kernel/hw_breakpoint.c:546:3: note: here default: ^~~~~~~
Rework so that the compiler doesn't warn about fall-through. Rework so the code looks like the arm code. Since the comment in the function indicates taht this is supposed to behave the same way as arm32 because
Typo: s/taht/that/
it handles 32-bit tasks also.
Cc: stable@vger.kernel.org # v3.16+ Fixes: 6ee33c2712fc ("ARM: hw_breakpoint: correct and simplify alignment fixup code") Signed-off-by: Anders Roxell anders.roxell@linaro.org
The patch itself looks fine, but I don't think this needs a CC to stable, nor does it require that fixes tag, as there's no functional problem.
Hmm... I now see I spoke too soon, and this is making the 1-byte breakpoint work at a 3-byte offset.
Given that:
Acked-by: Mark Rutland mark.rutland@arm.com
... and the fixes and stable tags are appropriate for that portion of the patch.
Sorry for the noise.
Thanks, Mark.
arch/arm64/kernel/hw_breakpoint.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index dceb84520948..ea616adf1cf1 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -535,14 +535,17 @@ int hw_breakpoint_arch_parse(struct perf_event *bp, case 0: /* Aligned */ break;
case 1:/* Allow single byte watchpoint. */if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)break;
/* Fall through */case 1:case 3:/* Allow single byte watchpoint. */if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)break;/* Fall through */-- 2.20.1