[PATCH 7/7] modpost: detect section mismatch for R_ARM_REL32

From: Masahiro Yamada
Date: Thu Jun 01 2023 - 08:11:38 EST


For ARM, modpost fails to detect some types of section mismatches.

[test code]

.section .init.data,"aw"
bar:
.long 0

.section .data,"aw"
.globl foo
foo:
.long bar - .

It is apparently a bad reference, but modpost does not report anything.

The test code above produces the following relocations.

Relocation section '.rel.data' at offset 0xe8 contains 1 entry:
Offset Info Type Sym.Value Sym. Name
00000000 00000403 R_ARM_REL32 00000000 .init.data

Currently, R_ARM_REL32 is just skipped.

Handle it like R_ARM_ABS32.

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

scripts/mod/modpost.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 55d142bb000b..9f0c87064ca5 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1281,6 +1281,7 @@ static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)

switch (r_typ) {
case R_ARM_ABS32:
+ case R_ARM_REL32:
inst = TO_NATIVE(*(uint32_t *)loc);
r->r_addend = inst + sym->st_value;
break;
--
2.39.2