Messages in this thread | | | From | Kees Cook <> | Date | Tue, 23 Aug 2016 22:37:43 -0400 | Subject | Re: [PATCH 2/2] mm/usercopy: enable usercopy size checking for modern versions of gcc |
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On Tue, Aug 23, 2016 at 3:28 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote: > This is a revert of: > > 2fb0815c9ee6 ("gcc4: disable __compiletime_object_size for GCC 4.6+") > > The goal of that commit was to silence the "provably correct" gcc > warnings. But it went too far: it also disabled the runtime warnings. > > Now that the pretty much useless gcc warnings have been properly > disposed of with the previous patch, re-enable this checking on modern > versions of gcc so we can get the runtime warnings again.
As far as I know, this will still be broken since it's __builtin_object_size() that is buggy. Maybe I'm misunderstanding which piece is busted, though?
-Kees
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > --- > include/linux/compiler-gcc.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index e294939..e7f7a68 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -158,7 +158,7 @@ > #define __compiler_offsetof(a, b) \ > __builtin_offsetof(a, b) > > -#if GCC_VERSION >= 40100 && GCC_VERSION < 40600 > +#if GCC_VERSION >= 40100 > # define __compiletime_object_size(obj) __builtin_object_size(obj, 0) > #endif > > -- > 2.7.4 >
-- Kees Cook Nexus Security
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