Messages in this thread | | | From | Masahiro Yamada <> | Date | Wed, 20 Mar 2019 22:55:06 +0900 | Subject | Re: [PATCH] x86/vdso: include generic __lshrdi3 in 32-bit vDSO |
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On Sat, Mar 16, 2019 at 4:55 AM Matthias Kaehlcke <mka@chromium.org> wrote: > > Building the 32-bit vDSO with a recent clang version fails due > to undefined symbols: > > arch/x86/entry/vdso/vdso32.so.dbg: undefined symbols found > > The undefined symbol in this case is __lshrdi3, which is part of > the compiler runtime library, however the vDSO isn't linked against > this library. > > Include the kernel version of __lshrdi3 in the 32-bit vDSO build. > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org> > --- > diff --git a/lib/lshrdi3.c b/lib/lshrdi3.c > index 99cfa5721f2d..8a4fc6bcf3a4 100644 > --- a/lib/lshrdi3.c > +++ b/lib/lshrdi3.c > @@ -16,7 +16,7 @@ > * to the Free Software Foundation, Inc. > */ > > -#include <linux/module.h> > +#include <linux/export.h> > #include <linux/libgcc.h> > > long long notrace __lshrdi3(long long u, word_type b) > @@ -42,4 +42,6 @@ long long notrace __lshrdi3(long long u, word_type b) > > return w.ll; > } > +#ifndef BUILD_VDSO > EXPORT_SYMBOL(__lshrdi3); > +#endif
I picked up https://patchwork.kernel.org/patch/10858565/
I do not know if this patch is still needed.
FYI, just a tip to turn EXPORT_SYMBOL into no-op cleanly.
You can use __DISABLE_EXPORTS as drivers/firmware/efi/libstub/Makefile does.
See commit f922c4abdf76.
-- Best Regards Masahiro Yamada
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