Commit 2772ae4d authored by WANG Xuerui's avatar WANG Xuerui Committed by Huacai Chen
Browse files

modpost: Ignore relaxation and alignment marker relocs on LoongArch 



With recent trunk versions of binutils and gcc, alignment directives are
represented with R_LARCH_ALIGN relocs on LoongArch, which is necessary
for the linker to maintain alignment requirements during its relaxation
passes. And even though the kernel is built with relaxation disabled, so
far a small number of R_LARCH_RELAX marker relocs are still emitted as
part of la.* pseudo instructions in assembly. These two kinds of relocs
do not refer to symbols, which can trip up modpost's section mismatch
checks, because the r_offset of said relocs can be zero or any other
meaningless value, eventually leading to a `from == NULL` condition in
default_mismatch_handler and SIGSEGV.

As the two kinds of relocs are not concerned with symbols, just ignore
them for section mismatch check purposes.

Signed-off-by: default avatarWANG Xuerui <git@xen0n.name>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 0dd3ee31

scripts/mod/modpost.c

+17 −2
Original line number Diff line number Diff line
@@ -1346,6 +1346,14 @@ static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type) 
#define R_LARCH_SUB32		55

#endif



#ifndef R_LARCH_RELAX

#define R_LARCH_RELAX		100

#endif



#ifndef R_LARCH_ALIGN

#define R_LARCH_ALIGN		102

#endif



static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,

				 unsigned int *r_type, unsigned int *r_sym)

{
@@ -1400,9 +1408,16 @@ static void section_rela(struct module *mod, struct elf_info *elf, 
				continue;

			break;

		case EM_LOONGARCH:

			if (!strcmp("__ex_table", fromsec) &&

			    r_type == R_LARCH_SUB32)

			switch (r_type) {

			case R_LARCH_SUB32:

				if (!strcmp("__ex_table", fromsec))

					continue;

				break;

			case R_LARCH_RELAX:

			case R_LARCH_ALIGN:

				/* These relocs do not refer to symbols */

				continue;

			}

			break;

		}