Re: [PATCH 00/21] objtool: vmlinux.o and CLANG LTO support

From: Josh Poimboeuf
Date: Fri Jan 15 2021 - 14:30:19 EST


On Fri, Jan 15, 2021 at 07:54:29PM +0100, Sedat Dilek wrote:
> > > I tried this series on top of clang-cfi and it segfaults here.
> > >
> > > + info OBJTOOL vmlinux.o
> > > + [ != silent_ ]
> > > + printf %-7s %s\n OBJTOOL vmlinux.o
> > > OBJTOOL vmlinux.o
> > > + tools/objtool/objtool orc generate --duplicate --mcount --vmlinux
> > > --no-fp --no-unreachable --retpoline --uaccess vmlinux.o
> > > Segmentation fault
> > > + on_exit
> > > + [ 139 -ne 0 ]
> > > + cleanup
> > > + rm -f .btf.*
> > > + rm -f .tmp_System.map
> > > + rm -f .tmp_initcalls.lds
> > > + rm -f .tmp_symversions.lds
> > > + rm -f .tmp_vmlinux*
> > > + rm -f System.map
> > > + rm -f vmlinux
> > > + rm -f vmlinux.o
> > > make[3]: *** [Makefile:1213: vmlinux] Error 139
> > >
> >
> > I re-tried with the latest clang-lto Git and switched to Debian's LLVM-11.0.1.
> > This build was successful.
> > No objtool-vmlinux warnings observed.
> >
> > In the next step I try with my selfmade LLVM-11.1.0-rc1 (to see if it's broken).
> >
>
> Good, my selfmade LLVM-11.1.0-rc1 is not broken with clang-lto.
>
> + info OBJTOOL vmlinux.o
> + [ != silent_ ]
> + printf %-7s %s\n OBJTOOL vmlinux.o
> OBJTOOL vmlinux.o
> + tools/objtool/objtool orc generate --duplicate --mcount --vmlinux
> --no-fp --no-unreachable --retpoline --uaccess vmlinux.o
> + make -f ./scripts/Makefile.modpost MODPOST_VMLINUX=1
> scripts/mod/modpost -m -o vmlinux.symvers vmlinux.o
> + info MODINFO modules.builtin.modinfo
>
> Josh and Sami, any idea what's going on with clang-cfi an this patchset?

No idea, I haven't seen this. Are you still able to recreate?

--
Josh