[PATCH 1/2] modules: Ensure natural alignment for .altinstructions and __bug_table sections

From: Helge Deller
Date: Mon Jun 27 2022 - 15:06:30 EST


In the kernel image vmlinux.lds.S linker scripts the .altinstructions
and __bug_table sections are 32- or 64-bit aligned because they hold 32-
and/or 64-bit values.

But for modules the module.lds.S linker script doesn't define a default
alignment yet, so the linker chooses the default byte-alignment, which
then leads to unnecessary unaligned memory accesses at runtime.

This patch adds the missing alignments.

Signed-off-by: Helge Deller <deller@xxxxxx>
---
scripts/module.lds.S | 2 ++
1 file changed, 2 insertions(+)

diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 1d0e1e4dc3d2..3a3aa2354ed8 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -27,6 +27,8 @@ SECTIONS {
.ctors 0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
.init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }

+ .altinstructions 0 : ALIGN(8) { KEEP(*(.altinstructions)) }
+ __bug_table 0 : ALIGN(8) { KEEP(*(__bug_table)) }
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }

__patchable_function_entries : { *(__patchable_function_entries) }
--
2.35.3