From 1c4a7587d1bbee0fd53b63af60e4244a62775f57 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 1 Nov 2023 02:46:27 +0900 Subject: [PATCH] modpost: fix section mismatch message for RELA The section mismatch check prints a bogus symbol name on some architectures. [test code] #include int __initdata foo; int get_foo(void) { return foo; } If you compile it with GCC for riscv or loongarch, modpost will show an incorrect symbol name: WARNING: modpost: vmlinux: section mismatch in reference: get_foo+0x8 (section: .text) -> done (section: .init.data) To get the correct symbol address, the st_value must be added. This issue has never been noticed since commit 93684d3b8062 ("kbuild: include symbol names in section mismatch warnings") presumably because st_value becomes zero on most architectures when the referenced symbol is looked up. It is not true for riscv or loongarch, at least. With this fix, modpost will show the correct symbol name: WARNING: modpost: vmlinux: section mismatch in reference: get_foo+0x8 (section: .text) -> foo (section: .init.data) Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers --- scripts/mod/modpost.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 973b5e5ae2dddc..cb6406f485a960 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1383,13 +1383,15 @@ static void section_rela(struct module *mod, struct elf_info *elf, const Elf_Rela *rela; for (rela = start; rela < stop; rela++) { + Elf_Sym *tsym; Elf_Addr taddr, r_offset; unsigned int r_type, r_sym; r_offset = TO_NATIVE(rela->r_offset); get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym); - taddr = TO_NATIVE(rela->r_addend); + tsym = elf->symtab_start + r_sym; + taddr = tsym->st_value + TO_NATIVE(rela->r_addend); switch (elf->hdr->e_machine) { case EM_RISCV: @@ -1404,7 +1406,7 @@ static void section_rela(struct module *mod, struct elf_info *elf, break; } - check_section_mismatch(mod, elf, elf->symtab_start + r_sym, + check_section_mismatch(mod, elf, tsym, fsecndx, fromsec, r_offset, taddr); } }