On Fri, Sep 04, 2015 at 10:58:31AM +0200, Ingo Molnar wrote: > > * Mikko Rapeli <[email protected]> wrote: > > > On Thu, Sep 03, 2015 at 09:42:32AM +0200, Ingo Molnar wrote: > > > > > > * Mikko Rapeli <[email protected]> wrote: > > > > > > > Hi Ingo, Thomas and Peter, > > > > > > > > Do you have any pointers for me how > > > > arch/x86/include/uapi/asm/sigcontext32.h > > > > could be fixed to also compile in userspace? Is definition of > > > > _fpx_sw_bytes > > > > or _fpstate_ia32 even needed there? > > > > > > > > Instructions to reproduce the userspace build failure are here: > > > > https://lkml.org/lkml/2015/5/30/98 > > > > > > Yeah, so this is a real bug in the headers, good find. > > > > > > Also note that somewhat luckily your testcase is artificial, no real > > > user-space > > > code can contain that code at the moment because the header never built > > > standalone > > > in the past either AFAICS. > > > > > > So it's an old header file dependency bug, to make it build in user-space > > > you need > > > to do this workaround: > > > > > > #include <asm/sigcontext.h> > > > #include <asm/sigcontext32.h> > > > > > > If you only include sigcontext32.h: > > > > > > #include <asm/sigcontext32.h> > > > > > > it will fail to build. > > > > > > To fix the bug: > > > > > > > > --- a/arch/x86/include/uapi/asm/sigcontext32.h > > > > > +++ b/arch/x86/include/uapi/asm/sigcontext32.h > > > > > @@ -45,7 +45,6 @@ struct _fpstate_ia32 { > > > > > __u32 padding[44]; > > > > > union { > > > > > __u32 padding2[12]; > > > > > - struct _fpx_sw_bytes sw_reserved; > > > > > }; > > > > > }; > > > > > > No, those fields are real and compat sigframe handling user-space might > > > be relying > > > on them. > > > > > > Does the fix below work for you? > > > > Unfortunately no: > > > > cc -Wall -c -nostdinc -I /usr/lib/gcc/i586-linux-gnu/5/include -I > > /usr/lib/gcc/i > > 586-linux-gnu/5/include-fixed -I . -I ../headers_compile_test_include -I > > ../head > > ers_compile_test_include/i586-linux-gnu ./asm/sigcontext32.c > > In file included from ./asm/sigcontext32.c:1:0: > > ./asm/sigcontext32.h:12:8: error: redefinition of ‘struct _fpreg’ > > struct _fpreg { > > ^ > > In file included from ./asm/sigcontext32.h:6:0, > > from ./asm/sigcontext32.c:1: > > ./asm/sigcontext.h:56:8: note: originally defined here > > struct _fpreg { > > ^ > > In file included from ./asm/sigcontext32.c:1:0: > > ./asm/sigcontext32.h:17:8: error: redefinition of ‘struct _fpxreg’ > > struct _fpxreg { > > ^ > > In file included from ./asm/sigcontext32.h:6:0, > > from ./asm/sigcontext32.c:1: > > ./asm/sigcontext.h:61:8: note: originally defined here > > struct _fpxreg { > > ^ > > In file included from ./asm/sigcontext32.c:1:0: > > ./asm/sigcontext32.h:23:8: error: redefinition of ‘struct _xmmreg’ > > struct _xmmreg { > > ^ > > In file included from ./asm/sigcontext32.h:6:0, > > from ./asm/sigcontext32.c:1: > > ./asm/sigcontext.h:67:8: note: originally defined here > > struct _xmmreg { > > ^ > > FAILED: ./asm/sigcontext32.h > > > > I guess this was the reason why I ended with the hack. > > sigcontext32.h is a 64-bit only header (for compat functionality), and you > are > trying to build this on i386, right?
Yes, i386 32bit. > In theory we could unify them mostly, the two structures match mostly, except > that > '_fpstate_ia32::padding' is named 'padding1' in _fpstate, and there's also > some > legacy uglies wrt. user-space sigcontext definitions. > > So this either gets cleaned up properly, with the legacy hacks/wrappers > clearly > isolated, or we could state that you shouldn't build 64-bit headers in 32-bit > environments. Should the sigcontext32.h have some 32bit ifdefs maybe? I assume that the exported header files should be the same for both 64 and 32 bit i386/x86 -Mikko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
