In order to improve kernel text protection, we need separate .init.text/ .init.data/.text in separate sections. However, RISC-V linker relaxation code is not aware of any alignment between sections. As a result, it may relax any RISCV_CALL relocations between sections to JAL without realizing that an inter section alignment may move the address farther. That may lead to a relocation truncated fit error. However, linker relaxation code is aware of the individual section alignments.
The detailed discussion on this issue can be found here. https://github.com/riscv/riscv-gnu-toolchain/issues/738 Keep the .init.text section aligned so that linker relaxation will take that as a hint while relaxing inter section calls. Here are the code size changes for each section because of this change. section change in size (in bytes) .head.text +4 .text +40 .init.text +6530 .exit.text +84 The only significant increase in size happened for .init.text because all intra relocations also use 2MB alignment. Suggested-by: Jim Wilson <[email protected]> Signed-off-by: Atish Patra <[email protected]> --- arch/riscv/kernel/vmlinux.lds.S | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 3ffbd6cbdb86..cacd7898ba7f 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -30,7 +30,13 @@ SECTIONS . = ALIGN(PAGE_SIZE); __init_begin = .; - INIT_TEXT_SECTION(PAGE_SIZE) + __init_text_begin = .; + .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) ALIGN(SECTION_ALIGN) { \ + _sinittext = .; \ + INIT_TEXT \ + _einittext = .; \ + } + . = ALIGN(8); __soc_early_init_table : { __soc_early_init_table_start = .; -- 2.25.1
