From: Arvind Sankar <nivedita@alum.mit.edu>
To: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@suse.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Peter Collingbourne <pcc@google.com>,
James Morse <james.morse@arm.com>, Ingo Molnar <mingo@redhat.com>,
Russell King <linux@armlinux.org.uk>,
Masahiro Yamada <masahiroy@kernel.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
x86@kernel.org, clang-built-linux@googlegroups.com,
linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 4/5] x86/build: Warn on orphan section placement
Date: Sat, 5 Sep 2020 18:48:35 -0400 [thread overview]
Message-ID: <20200905224835.GA1500331@rani.riverdale.lan> (raw)
In-Reply-To: <20200902025347.2504702-5-keescook@chromium.org>
On Tue, Sep 01, 2020 at 07:53:46PM -0700, Kees Cook wrote:
> We don't want to depend on the linker's orphan section placement
> heuristics as these can vary between linkers, and may change between
> versions. All sections need to be explicitly handled in the linker script.
>
> Now that all sections are explicitly handled, enable orphan section
> warnings.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> arch/x86/Makefile | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 4346ffb2e39f..154259f18b8b 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -209,6 +209,10 @@ ifdef CONFIG_X86_64
> LDFLAGS_vmlinux += -z max-page-size=0x200000
> endif
>
> +# We never want expected sections to be placed heuristically by the
> +# linker. All sections should be explicitly named in the linker script.
> +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)
> +
> archscripts: scripts_basic
> $(Q)$(MAKE) $(build)=arch/x86/tools relocs
>
> --
> 2.25.1
>
With LLVM=1 and GCOV_KERNEL/GCOV_PROFILE_ALL enabled, there are
.eh_frame sections created. I see that KASAN and KCSAN currently discard
them. Does GCOV actually need them or should it also discard?
Thanks.
WARNING: multiple messages have this Message-ID (diff)
From: Arvind Sankar <nivedita@alum.mit.edu>
To: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Masahiro Yamada <masahiroy@kernel.org>,
x86@kernel.org, Nick Desaulniers <ndesaulniers@google.com>,
Russell King <linux@armlinux.org.uk>,
Ard Biesheuvel <ardb@kernel.org>,
clang-built-linux@googlegroups.com,
Arvind Sankar <nivedita@alum.mit.edu>,
Ingo Molnar <mingo@redhat.com>, James Morse <james.morse@arm.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Borislav Petkov <bp@suse.de>,
Peter Collingbourne <pcc@google.com>,
Ingo Molnar <mingo@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v7 4/5] x86/build: Warn on orphan section placement
Date: Sat, 5 Sep 2020 18:48:35 -0400 [thread overview]
Message-ID: <20200905224835.GA1500331@rani.riverdale.lan> (raw)
In-Reply-To: <20200902025347.2504702-5-keescook@chromium.org>
On Tue, Sep 01, 2020 at 07:53:46PM -0700, Kees Cook wrote:
> We don't want to depend on the linker's orphan section placement
> heuristics as these can vary between linkers, and may change between
> versions. All sections need to be explicitly handled in the linker script.
>
> Now that all sections are explicitly handled, enable orphan section
> warnings.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> arch/x86/Makefile | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 4346ffb2e39f..154259f18b8b 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -209,6 +209,10 @@ ifdef CONFIG_X86_64
> LDFLAGS_vmlinux += -z max-page-size=0x200000
> endif
>
> +# We never want expected sections to be placed heuristically by the
> +# linker. All sections should be explicitly named in the linker script.
> +LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)
> +
> archscripts: scripts_basic
> $(Q)$(MAKE) $(build)=arch/x86/tools relocs
>
> --
> 2.25.1
>
With LLVM=1 and GCOV_KERNEL/GCOV_PROFILE_ALL enabled, there are
.eh_frame sections created. I see that KASAN and KCSAN currently discard
them. Does GCOV actually need them or should it also discard?
Thanks.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-05 22:48 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 2:53 [PATCH v7 0/5] Warn on orphan section placement Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-02 2:53 ` [PATCH v7 1/5] arm64/build: " Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-07 6:05 ` [tip: core/build] " tip-bot2 for Kees Cook
2020-09-02 2:53 ` [PATCH v7 2/5] arm/build: " Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-07 6:05 ` [tip: core/build] " tip-bot2 for Kees Cook
2020-09-02 2:53 ` [PATCH v7 3/5] arm/boot: " Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-07 6:05 ` [tip: core/build] " tip-bot2 for Kees Cook
2020-09-02 2:53 ` [PATCH v7 4/5] x86/build: " Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-05 22:48 ` Arvind Sankar [this message]
2020-09-05 22:48 ` Arvind Sankar
2020-09-08 20:17 ` Arvind Sankar
2020-09-08 20:17 ` Arvind Sankar
2020-09-07 6:05 ` [tip: core/build] " tip-bot2 for Kees Cook
2020-09-02 2:53 ` [PATCH v7 5/5] x86/boot/compressed: " Kees Cook
2020-09-02 2:53 ` Kees Cook
2020-09-02 14:38 ` kernel test robot
2020-09-02 18:49 ` Kees Cook
2020-09-07 6:05 ` [tip: core/build] " tip-bot2 for Kees Cook
2020-09-02 19:04 ` [PATCH v7 0/5] " Nick Desaulniers
2020-09-02 19:04 ` Nick Desaulniers
2020-09-04 5:58 ` Ingo Molnar
2020-09-04 5:58 ` Ingo Molnar
2020-09-04 18:20 ` Kees Cook
2020-09-04 18:20 ` Kees Cook
2020-09-06 7:24 ` Ingo Molnar
2020-09-06 7:24 ` Ingo Molnar
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