From: Nathan Chancellor <natechancellor@gmail.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Joe Lawrence <joe.lawrence@redhat.com>,
Christophe Leroy <christophe.leroy@c-s.fr>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com,
Kees Cook <keescook@chromium.org>,
Fangrui Song <maskray@google.com>
Subject: Re: [PATCH 0/2] link vdso with linker
Date: Tue, 1 Sep 2020 22:21:23 -0700 [thread overview]
Message-ID: <20200902052123.GA2687902@ubuntu-n2-xlarge-x86> (raw)
In-Reply-To: <20200901222523.1941988-1-ndesaulniers@google.com>
On Tue, Sep 01, 2020 at 03:25:21PM -0700, Nick Desaulniers wrote:
> Kees Cook is working on series that adds --orphan-section=warn to arm,
> arm64, and x86. I noticed that ppc vdso were still using cc-ldoption
> for these which I removed. It seems this results in that flag being
> silently dropped.
>
> I'm very confident with the first patch, but the second needs closer
> review around the error mentioned below the fold related to the .got
> section.
>
> Nick Desaulniers (2):
> powerpc/vdso64: link vdso64 with linker
> powerpc/vdso32: link vdso64 with linker
>
> arch/powerpc/include/asm/vdso.h | 17 ++---------------
> arch/powerpc/kernel/vdso32/Makefile | 7 +++++--
> arch/powerpc/kernel/vdso32/vdso32.lds.S | 3 ++-
> arch/powerpc/kernel/vdso64/Makefile | 8 ++++++--
> arch/powerpc/kernel/vdso64/vdso64.lds.S | 1 -
> 5 files changed, 15 insertions(+), 21 deletions(-)
>
> --
> 2.28.0.402.g5ffc5be6b7-goog
>
ppc44x_defconfig and powernv_defconfig start failing with this series
when LD=ld.lld is used.
$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- LLVM=1 O=out/ppc32 distclean ppc44x_defconfig uImage
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_gettimeofday)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_clock_gettime)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_clock_getres)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_time)
...
$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out/ppc64le distclean powernv_defconfig zImage.epapr
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_gettimeofday)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_clock_gettime)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_clock_getres)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_time)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/cacheflush.o:(__kernel_sync_dicache)
...
We need Fangrui's patch to fix ppc44x_defconfig:
https://lore.kernel.org/lkml/20200205005054.k72fuikf6rwrgfe4@google.com/
That exact same fix is needed in arch/powerpc/kernel/vdso64/datapage.S
to fix powernv_defconfig.
Cheers,
Nathan
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <natechancellor@gmail.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>,
Joe Lawrence <joe.lawrence@redhat.com>,
Kees Cook <keescook@chromium.org>,
Fangrui Song <maskray@google.com>,
linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>,
clang-built-linux@googlegroups.com,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 0/2] link vdso with linker
Date: Tue, 1 Sep 2020 22:21:23 -0700 [thread overview]
Message-ID: <20200902052123.GA2687902@ubuntu-n2-xlarge-x86> (raw)
In-Reply-To: <20200901222523.1941988-1-ndesaulniers@google.com>
On Tue, Sep 01, 2020 at 03:25:21PM -0700, Nick Desaulniers wrote:
> Kees Cook is working on series that adds --orphan-section=warn to arm,
> arm64, and x86. I noticed that ppc vdso were still using cc-ldoption
> for these which I removed. It seems this results in that flag being
> silently dropped.
>
> I'm very confident with the first patch, but the second needs closer
> review around the error mentioned below the fold related to the .got
> section.
>
> Nick Desaulniers (2):
> powerpc/vdso64: link vdso64 with linker
> powerpc/vdso32: link vdso64 with linker
>
> arch/powerpc/include/asm/vdso.h | 17 ++---------------
> arch/powerpc/kernel/vdso32/Makefile | 7 +++++--
> arch/powerpc/kernel/vdso32/vdso32.lds.S | 3 ++-
> arch/powerpc/kernel/vdso64/Makefile | 8 ++++++--
> arch/powerpc/kernel/vdso64/vdso64.lds.S | 1 -
> 5 files changed, 15 insertions(+), 21 deletions(-)
>
> --
> 2.28.0.402.g5ffc5be6b7-goog
>
ppc44x_defconfig and powernv_defconfig start failing with this series
when LD=ld.lld is used.
$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- LLVM=1 O=out/ppc32 distclean ppc44x_defconfig uImage
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_gettimeofday)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_clock_gettime)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_clock_getres)
ld.lld: error: relocation R_PPC_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso32/datapage.o
>>> referenced by arch/powerpc/kernel/vdso32/gettimeofday.o:(__kernel_time)
...
$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out/ppc64le distclean powernv_defconfig zImage.epapr
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_gettimeofday)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_clock_gettime)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_clock_getres)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/gettimeofday.o:(__kernel_time)
ld.lld: error: relocation R_PPC64_REL16_LO cannot be used against symbol __kernel_datapage_offset; recompile with -fPIC
>>> defined in arch/powerpc/kernel/vdso64/datapage.o
>>> referenced by arch/powerpc/kernel/vdso64/cacheflush.o:(__kernel_sync_dicache)
...
We need Fangrui's patch to fix ppc44x_defconfig:
https://lore.kernel.org/lkml/20200205005054.k72fuikf6rwrgfe4@google.com/
That exact same fix is needed in arch/powerpc/kernel/vdso64/datapage.S
to fix powernv_defconfig.
Cheers,
Nathan
next prev parent reply other threads:[~2020-09-02 5:21 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-01 22:25 [PATCH 0/2] link vdso with linker Nick Desaulniers
2020-09-01 22:25 ` Nick Desaulniers
2020-09-01 22:25 ` [PATCH 1/2] powerpc/vdso64: link vdso64 " Nick Desaulniers
2020-09-01 22:25 ` Nick Desaulniers
2020-09-02 12:14 ` Michael Ellerman
2020-09-02 12:14 ` Michael Ellerman
2020-09-02 17:41 ` Nick Desaulniers
2020-09-02 17:41 ` Nick Desaulniers
2020-09-02 18:02 ` Christophe Leroy
2021-04-22 22:44 ` Nick Desaulniers
2021-04-22 22:44 ` Nick Desaulniers
2021-04-23 7:40 ` Christophe Leroy
2021-04-23 7:40 ` Christophe Leroy
2021-04-23 17:18 ` Christophe Leroy
2021-04-23 17:18 ` Christophe Leroy
2022-03-02 16:48 ` Christophe Leroy
2020-09-01 22:25 ` [PATCH 2/2] powerpc/vdso32: " Nick Desaulniers
2020-09-01 22:25 ` Nick Desaulniers
2020-09-02 2:58 ` Kees Cook
2020-09-02 2:58 ` Kees Cook
2020-09-02 6:46 ` Christophe Leroy
2020-09-02 6:46 ` Christophe Leroy
2020-09-02 14:14 ` Segher Boessenkool
2020-09-02 14:14 ` Segher Boessenkool
2020-09-02 15:43 ` Christophe Leroy
2020-09-02 15:43 ` Christophe Leroy
2020-09-02 16:57 ` Segher Boessenkool
2020-09-02 16:57 ` Segher Boessenkool
2020-09-02 7:56 ` Christophe Leroy
2020-09-02 7:56 ` Christophe Leroy
2020-09-02 10:16 ` Christophe Leroy
2020-09-02 10:16 ` Christophe Leroy
2020-09-02 5:21 ` Nathan Chancellor [this message]
2020-09-02 5:21 ` [PATCH 0/2] link vdso " Nathan Chancellor
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