modpost: fix section mismatch message for RELA

[ Upstream commit 1c4a7587d1 ]

The section mismatch check prints a bogus symbol name on some
architectures.

[test code]

  #include <linux/init.h>

  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 93684d3b80 ("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 <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Masahiro Yamada 2023-11-01 02:46:27 +09:00 committed by Greg Kroah-Hartman
parent 9a07b662e5
commit b1205cc72b
1 changed files with 4 additions and 2 deletions

View File

@ -1496,13 +1496,15 @@ static void section_rela(struct module *mod, struct elf_info *elf,
return;
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:
@ -1517,7 +1519,7 @@ 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);
}
}