LLD always splits sections with LTO, which increases module sizes. This
change adds linker script rules to merge the split sections in the final
module.
Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
scripts/module.lds.S | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 69b9b71a6a47..18d5b8423635 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -23,6 +23,30 @@ SECTIONS {
.init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
+
+ __patchable_function_entries : { *(__patchable_function_entries) }
+
+ /*
+ * With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
+ * -ffunction-sections, which increases the size of the final module.
+ * Merge the split sections in the final binary.
+ */
+ .bss : {
+ *(.bss .bss.[0-9a-zA-Z_]*)
+ *(.bss..L*)
+ }
+
+ .data : {
+ *(.data .data.[0-9a-zA-Z_]*)
+ *(.data..L*)
+ }
+
+ .rodata : {
+ *(.rodata .rodata.[0-9a-zA-Z_]*)
+ *(.rodata..L*)
+ }
+
+ .text : { *(.text .text.[0-9a-zA-Z_]*) }
}
/* bring in arch-specific sections */
--
2.29.2.576.ga3fc446d84-goog
