[PATCH 2/4] modules: Ensure 64-bit alignment on __ksymtab_* sections

From: deller@kernel.org
To: linux-kernel@vger.kernel.org,
	Masahiro Yamada <masahiroy@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-modules@vger.kernel.org, linux-arch@vger.kernel.org,
	Luis Chamberlain <mcgrof@kernel.org>
Subject: [PATCH 2/4] modules: Ensure 64-bit alignment on __ksymtab_* sections
Date: Wed, 22 Nov 2023 23:18:12 +0100	[thread overview]
Message-ID: <20231122221814.139916-3-deller@kernel.org> (raw)
In-Reply-To: <20231122221814.139916-1-deller@kernel.org>

From: Helge Deller <deller@gmx.de>

On 64-bit architectures without CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
(e.g. ppc64, ppc64le, parisc, s390x,...) the __KSYM_REF() macro stores
64-bit pointers into the __ksymtab* sections.
Make sure that those sections will be correctly aligned at module link time,
otherwise unaligned memory accesses may happen at runtime.

The __kcrctab* sections store 32-bit entities, so use ALIGN(4) for those.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+
---
 scripts/module.lds.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index bf5bcf2836d8..b00415a9ff27 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -15,10 +15,10 @@ SECTIONS {
 		*(.discard.*)
 	}
 
-	__ksymtab		0 : { *(SORT(___ksymtab+*)) }
-	__ksymtab_gpl		0 : { *(SORT(___ksymtab_gpl+*)) }
-	__kcrctab		0 : { *(SORT(___kcrctab+*)) }
-	__kcrctab_gpl		0 : { *(SORT(___kcrctab_gpl+*)) }
+	__ksymtab		0 : ALIGN(8) { *(SORT(___ksymtab+*)) }
+	__ksymtab_gpl		0 : ALIGN(8) { *(SORT(___ksymtab_gpl+*)) }
+	__kcrctab		0 : ALIGN(4) { *(SORT(___kcrctab+*)) }
+	__kcrctab_gpl		0 : ALIGN(4) { *(SORT(___kcrctab_gpl+*)) }
 
 	.ctors			0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
 	.init_array		0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
-- 
2.41.0

