No, let's not. Why? Because if we do that we may inadvertently create an ABI which is hard to support across the board.
Stefani Seibold <stef...@seibold.net> wrote: >Am Mittwoch, den 12.12.2012, 15:34 -0800 schrieb H. Peter Anvin: >> On 12/12/2012 12:19 PM, stef...@seibold.net wrote: >> > diff --git a/arch/x86/vdso/vdso32/vclock_gettime.c >b/arch/x86/vdso/vdso32/vclock_gettime.c >> > new file mode 100644 >> > index 0000000..c9a1909 >> > --- /dev/null >> > +++ b/arch/x86/vdso/vdso32/vclock_gettime.c >> > @@ -0,0 +1,7 @@ >> > +/* >> > + * since vgtod layout differs between X86_64 and x86_32, it is not >possible to >> > + * provide a 32 bit vclock with a 64 bit kernel >> > + */ >> > +#ifdef CONFIG_X86_32 >> > +#include "../vclock_gettime.c" >> > +#endif >> >> This is where this goes fail. Sorry, it is not acceptable to >introduce >> an ABI on x86-32 without providing it also on x86-64 in compatibility >mode. >> >> I also don't believe it is not possible... it might require some more > >> cleverness; perhaps we need to do the 32-bit vgtod in such a way that >it >> *is* compatible with 64 bits. >> > >The comment is ambiguous: > >Since vgtod layout differs between X86_64 and x86_32 AND the vgtod is >not inside the accessible address space of a 32 bit program, it is >CURRENTLY not possible to provide a 32 bit vclock with a 64 bit kernel > >As i understand VDSO it is an alternativ way, so if there is no support >for it, there must be a fall back to the system call interface in the >program or lib, which tries to use it. > >So there is no drawback for 32 bit programs running on a 64 bit kernel. > > >I think this feature is not so important and can implemented in a >subsequent patch, because a 64 bit kernel system mostly runs 64 bit >programs. Let us fix this things step by step. > >- Stefani -- Sent from my mobile phone. Please excuse brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
