Messages in this thread | | | Date | Wed, 27 Nov 2013 15:36:11 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: override __compiletime_object_size() |
| |
* Jan Beulich <JBeulich@suse.com> wrote:
> >>> On 27.11.13 at 15:03, Ingo Molnar <mingo@kernel.org> wrote: > > > * Jan Beulich <JBeulich@suse.com> wrote: > > > >> As discussed in the context of commits 3df7b41a ("x86: Unify > >> copy_from_user() size checking") and 7a3d9b0f ("x86: Unify > >> copy_to_user() and add size checking to it"), we want to leverage > >> __builtin_object_size() also on newer gcc versions, but with other > >> architectures still using another model of copy_*_user() verification > >> we can't replace the global definition. Do it in the (only) header > >> needing the construct for now. > >> > >> Signed-off-by: Jan Beulich <jbeulich@suse.com> > >> Cc: Arjan van de Ven <arjan@linux.intel.com> > >> Cc: Guenter Roeck <linux@roeck-us.net> > >> --- > >> arch/x86/include/asm/uaccess.h | 6 ++++++ > >> 1 file changed, 6 insertions(+) > >> > >> --- 3.13-rc1/arch/x86/include/asm/uaccess.h > >> +++ 3.13-rc1-x86-compiletime-object-size/arch/x86/include/asm/uaccess.h > >> @@ -584,6 +584,12 @@ __copy_from_user_overflow(int size, unsi > >> > >> #endif > >> > >> +/* linux/compiler-gcc4.h restricts this to gcc < 4.6, which doesn't suit us. */ > >> +#if defined(__GNUC__) && GCC_VERSION >= 40100 > >> +# undef __compiletime_object_size > >> +# define __compiletime_object_size(obj) __builtin_object_size(obj, 0) > >> +#endif > >> + > > > > Would be nice to have a more verbose changelog that explains what > > benefits this brings us. > > That makes no sense to me - the benefits of this construct should > have been explained with its introduction; the change here just > makes it being used under wider range of compilers (and the code > comment already says exactly that).
Yes indeed - I should have read the referenced changelog...
Thanks, will apply it as-is, if there are no objections from others.
Thanks,
Ingo
| |