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: Petr Mladek <[e-mail]>
Tested-by: Joe Lawrence <[e-mail]>
Signed-off-by: Josh Poimboeuf <[e-mail]>

arch/x86/kernel/module.c

···
 	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;
 
···
 
 		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);
···
 	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

···
 	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;
 		}