Commit bf770d6d authored by Josh Poimboeuf's avatar Josh Poimboeuf
Browse files

x86/module: Improve relocation error messages 



Add the section number and reloc index to relocation error messages to
help find the faulty relocation.

Acked-by: default avatarPetr Mladek <pmladek@suse.com>
Tested-by: default avatarJoe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
parent 1ba9f897

arch/x86/kernel/module.c

+9 −6
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs, 
	DEBUGP("%s relocate section %u to %u\n",

	       apply ? "Applying" : "Clearing",

	       relsec, sechdrs[relsec].sh_info);



	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {

		size_t size;
@@ -162,15 +163,17 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs, 


		if (apply) {

			if (memcmp(loc, &zero, size)) {

				pr_err("x86/modules: Invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n",

				       (int)ELF64_R_TYPE(rel[i].r_info), loc, val);

				pr_err("x86/modules: Invalid relocation target, existing value is nonzero for sec %u, idx %u, type %d, loc %lx, val %llx\n",

				       relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),

				       (unsigned long)loc, val);

				return -ENOEXEC;

			}

			write(loc, &val, size);

		} else {

			if (memcmp(loc, &val, size)) {

				pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for type %d, loc %p, val %Lx\n",

					(int)ELF64_R_TYPE(rel[i].r_info), loc, val);

				pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for sec %u, idx %u, type %d, loc %lx, val %llx\n",

					relsec, i, (int)ELF64_R_TYPE(rel[i].r_info),

					(unsigned long)loc, val);

				return -ENOEXEC;

			}

			write(loc, &zero, size);
@@ -179,8 +182,8 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs, 
	return 0;



overflow:

	pr_err("overflow in relocation type %d val %Lx\n",

	       (int)ELF64_R_TYPE(rel[i].r_info), val);

	pr_err("overflow in relocation type %d val %llx sec %u idx %d\n",

	       (int)ELF64_R_TYPE(rel[i].r_info), val, relsec, i);

	pr_err("`%s' likely not compiled with -mcmodel=kernel\n",

	       me->name);

	return -ENOEXEC;

kernel/livepatch/core.c

+2 −2
Original line number Diff line number Diff line
@@ -217,8 +217,8 @@ static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab, 
	for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {

		sym = (Elf_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info);

		if (sym->st_shndx != SHN_LIVEPATCH) {

			pr_err("symbol %s is not marked as a livepatch symbol\n",

			       strtab + sym->st_name);

			pr_err("symbol %s at rela sec %u idx %d is not marked as a livepatch symbol\n",

			       strtab + sym->st_name, symndx, i);

			return -EINVAL;

		}