Messages in this thread | | | Date | Fri, 26 Jul 2019 13:10:57 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH 1/3] arm64: perf: Mark expected switch fall-through |
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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.
If anything, it fixes:
d93512ef0f0e (" Makefile: Globally enable fall-through warning")
... given the commit message for that patch states:
Now that all the fall-through warnings have been addressed in the kernel, enable the fall-through warning globally.
... and the existence of this patch implies otherwise.
IIUC that patch isn't even in mainline yet, but given this is simple I imagine that Will and Catalin might be happy to pick this up for the next rc.
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; > case 2: > /* Allow halfword watchpoints and breakpoints. */ > if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2) > break; > + /* Fall through */ > + case 1: > + case 3: > + /* Allow single byte watchpoint. */ > + if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1) > + break; > + /* Fall through */ > default: > return -EINVAL; > } > -- > 2.20.1 >
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