From: Sami Tolvanen <samitolvanen@xxxxxxxxxx> commit dd2776222abb9893e5b5c237a2c8c880d8854cee upstream. 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> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20201211184633.3213045-6-samitolvanen@xxxxxxxxxx Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- scripts/module.lds.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) --- 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 */
