Messages in this thread Patch in this message |  | | From | Masahiro Yamada <> | | Subject | [PATCH] modpost: fix section mismatch message for R_ARM_ABS32 | | Date | Mon, 15 May 2023 09:54:19 +0900 |
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The section mismatch check does not show proper warning messages for ARM.
Here, very simple test code.
#include <linux/init.h>
static int __initdata foo;
void set_foo(int x) { foo = x; }
int get_foo(int x) { return foo; }
If I compile it for ARM, modpost does not show the symbol name.
WARNING: modpost: vmlinux.o: section mismatch in reference: set_foo (section: .text) -> (unknown) (section: .init.data) WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> (unknown) (section: .init.data)
If I compile it for other architectures, modpost shows the correct symbol name.
WARNING: modpost: vmlinux.o: section mismatch in reference: set_foo (section: .text) -> foo (section: .init.data) WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)
For R_ARM_ABS32, addend_arm_rel() sets r->r_addend to a wrong value.
arch/arm/kernel/module.c handles R_ARM_ABS32 as follows:
case R_ARM_ABS32: case R_ARM_TARGET1: *(u32 *)loc += sym->st_value;
I just mimicked it in modpost.
Fixes: 56a974fa2d59 ("kbuild: make better section mismatch reports on arm") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> ---
scripts/mod/modpost.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index d4531d09984d..c93780d93caf 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1460,12 +1460,13 @@ static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) { unsigned int r_typ = ELF_R_TYPE(r->r_info); + unsigned int *location = reloc_location(elf, sechdr, r); + Elf_Sym *sym; switch (r_typ) { case R_ARM_ABS32: - /* From ARM ABI: (S + A) | T */ - r->r_addend = (int)(long) - (elf->symtab_start + ELF_R_SYM(r->r_info)); + sym = elf->symtab_start + ELF_R_SYM(r->r_info); + r->r_addend = TO_NATIVE(*location) + sym->st_value; break; case R_ARM_PC24: case R_ARM_CALL: -- 2.39.2
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