Messages in this thread | | | From | Nick Desaulniers <> | Date | Thu, 7 Mar 2019 16:53:34 -0800 | Subject | Re: [PATCH] x86/hw_breakpoints: Return -EINVAL in default case in hw_breakpoint_arch_parse |
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On Thu, Mar 7, 2019 at 1:28 PM Nathan Chancellor <natechancellor@gmail.com> wrote: > > When building with -Wsometimes-uninitialized, Clang warns: > > arch/x86/kernel/hw_breakpoint.c:355:2: warning: variable 'align' is used > uninitialized whenever switch default is taken > [-Wsometimes-uninitialized] > > It's not wrong but we can see that arch_build_bp_info will only ever > initialize hw->len to one of the specified switch cases. We can easily > silence Clang by just returning -EINVAL in the default case so that we > can never use align without initializing it first.
And the call site just bubbles up return codes anyways. Thanks for sending. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Link: https://github.com/ClangBuiltLinux/linux/issues/392 > Suggested-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> > --- > arch/x86/kernel/hw_breakpoint.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c > index ff9bfd40429e..d73083021002 100644 > --- a/arch/x86/kernel/hw_breakpoint.c > +++ b/arch/x86/kernel/hw_breakpoint.c > @@ -354,6 +354,7 @@ int hw_breakpoint_arch_parse(struct perf_event *bp, > #endif > default: > WARN_ON_ONCE(1); > + return -EINVAL; > } > > /* > -- > 2.21.0 >
-- Thanks, ~Nick Desaulniers
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