linux-kernel - [RFC PATCH 2/5] vmlinux: Avoid weak reference to notes section

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Message-ID: <20240122090851.851120-9-ardb+git@google.com>
Date: Mon, 22 Jan 2024 10:08:54 +0100
From: Ard Biesheuvel <ardb+git@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Ard Biesheuvel <ardb@...nel.org>, Kevin Loughlin <kevinloughlin@...gle.com>, 
	Tom Lendacky <thomas.lendacky@....com>, Dionna Glaze <dionnaglaze@...gle.com>, 
	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, Andy Lutomirski <luto@...nel.org>, 
	Arnd Bergmann <arnd@...db.de>, Martin KaFai Lau <martin.lau@...ux.dev>, 
	Nathan Chancellor <nathan@...nel.org>, Nick Desaulniers <ndesaulniers@...gle.com>, 
	Justin Stitt <justinstitt@...gle.com>, linux-arch@...r.kernel.org, bpf@...r.kernel.org, 
	llvm@...ts.linux.dev
Subject: [RFC PATCH 2/5] vmlinux: Avoid weak reference to notes section

From: Ard Biesheuvel <ardb@...nel.org>

Weak references are references that are permitted to remain unsatisfied
in the final link. This means they cannot be implemented using place
relative relocations, resulting in GOT entries when using position
independent code generation.

The notes section should always exist, so the weak annotations can be
omitted.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
---
 kernel/ksysfs.c | 4 ++--
 lib/buildid.c   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 1d4bc493b2f4..347beb763c59 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -226,8 +226,8 @@ KERNEL_ATTR_RW(rcu_normal);
 /*
  * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
  */
-extern const void __start_notes __weak;
-extern const void __stop_notes __weak;
+extern const void __start_notes;
+extern const void __stop_notes;
 #define	notes_size (&__stop_notes - &__start_notes)
 
 static ssize_t notes_read(struct file *filp, struct kobject *kobj,
diff --git a/lib/buildid.c b/lib/buildid.c
index e3a7acdeef0e..15109fe191ae 100644
--- a/lib/buildid.c
+++ b/lib/buildid.c
@@ -182,8 +182,8 @@ unsigned char vmlinux_build_id[BUILD_ID_SIZE_MAX] __ro_after_init;
  */
 void __init init_vmlinux_build_id(void)
 {
-	extern const void __start_notes __weak;
-	extern const void __stop_notes __weak;
+	extern const void __start_notes;
+	extern const void __stop_notes;
 	unsigned int size = &__stop_notes - &__start_notes;
 
 	build_id_parse_buf(&__start_notes, vmlinux_build_id, size);
-- 
2.43.0.429.g432eaa2c6b-goog