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From:   Kees Cook <keescook@chromium.org>
To:     Ingo Molnar <mingo@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Fangrui Song <maskray@google.com>,
        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>,
        Borislav Petkov <bp@suse.de>, Ingo Molnar <mingo@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Arvind Sankar <nivedita@alum.mit.edu>,
        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: [PATCH v6 16/29] arm/build: Explicitly keep .ARM.attributes sections
Date:   Fri, 21 Aug 2020 12:42:57 -0700
Message-Id: <20200821194310.3089815-17-keescook@chromium.org>
In-Reply-To: <20200821194310.3089815-1-keescook@chromium.org>
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In preparation for adding --orphan-handling=warn, explicitly keep the
.ARM.attributes section (at address 0[1]) by expanding the existing
ELF_DETAILS macro into ARM_DETAILS.

[1] https://reviews.llvm.org/D85867

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOdk-racgq5pxsoGS6Vtifbtrk5fmkmnoLxrQMaOvV0nPWw@mail.gmail.com/
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/include/asm/vmlinux.lds.h | 4 ++++
 arch/arm/kernel/vmlinux-xip.lds.S  | 2 +-
 arch/arm/kernel/vmlinux.lds.S      | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h
index a08f4301b718..c4af5182ab48 100644
--- a/arch/arm/include/asm/vmlinux.lds.h
+++ b/arch/arm/include/asm/vmlinux.lds.h
@@ -52,6 +52,10 @@
 		ARM_MMU_DISCARD(*(__ex_table))				\
 		COMMON_DISCARDS
 
+#define ARM_DETAILS							\
+		ELF_DETAILS						\
+		.ARM.attributes 0 : { *(.ARM.attributes) }
+
 #define ARM_STUBS_TEXT							\
 		*(.gnu.warning)						\
 		*(.glue_7)						\
diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 904c31fa20ed..57fcbf55f913 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -150,7 +150,7 @@ SECTIONS
 	_end = .;
 
 	STABS_DEBUG
-	ELF_DETAILS
+	ARM_DETAILS
 }
 
 /*
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index bb950c896a67..1d3d3b599635 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -149,7 +149,7 @@ SECTIONS
 	_end = .;
 
 	STABS_DEBUG
-	ELF_DETAILS
+	ARM_DETAILS
 }
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
-- 
2.25.1