1 files changed, 39 insertions, 13 deletions

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 0cd39954d5a1..28d15ba58a26 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -59,7 +59,7 @@ static void klp_find_object_module(struct klp_object *obj)
 	if (!klp_is_module(obj))
 		return;
 
-	rcu_read_lock_sched();
+	guard(rcu)();
 	/*
 	 * We do not want to block removal of patched modules and therefore
 	 * we do not take a reference here. The patches are removed by
@@ -75,8 +75,6 @@ static void klp_find_object_module(struct klp_object *obj)
 	 */
 	if (mod && mod->klp_alive)
 		obj->mod = mod;
-
-	rcu_read_unlock_sched();
 }
 
 static bool klp_initialized(void)
@@ -90,8 +88,14 @@ static struct klp_func *klp_find_func(struct klp_object *obj,
 	struct klp_func *func;
 
 	klp_for_each_func(obj, func) {
+		/*
+		 * Besides identical old_sympos, also consider old_sympos
+		 * of 0 and 1 are identical.
+		 */
 		if ((strcmp(old_func->old_name, func->old_name) == 0) &&
-		    (old_func->old_sympos == func->old_sympos)) {
+		    ((old_func->old_sympos == func->old_sympos) ||
+		     (old_func->old_sympos == 0 && func->old_sympos == 1) ||
+		     (old_func->old_sympos == 1 && func->old_sympos == 0))) {
 			return func;
 		}
 	}
@@ -219,14 +223,14 @@ 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;
 		}
 
 		/* Format: .klp.sym.sym_objname.sym_name,sympos */
 		cnt = sscanf(strtab + sym->st_name,
-			     ".klp.sym.%55[^.].%511[^,],%lu",
+			     KLP_SYM_PREFIX "%55[^.].%511[^,],%lu",
 			     sym_objname, sym_name, &sympos);
 		if (cnt != 3) {
 			pr_err("symbol %s has an incorrectly formatted name\n",
@@ -305,7 +309,7 @@ static int klp_write_section_relocs(struct module *pmod, Elf_Shdr *sechdrs,
 	 * See comment in klp_resolve_symbols() for an explanation
 	 * of the selected field width value.
 	 */
-	cnt = sscanf(shstrtab + sec->sh_name, ".klp.rela.%55[^.]",
+	cnt = sscanf(shstrtab + sec->sh_name, KLP_RELOC_SEC_PREFIX "%55[^.]",
 		     sec_objname);
 	if (cnt != 1) {
 		pr_err("section %s has an incorrectly formatted name\n",
@@ -521,7 +525,7 @@ static struct klp_object *klp_alloc_object_dynamic(const char *name,
 {
 	struct klp_object *obj;
 
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	obj = kzalloc_obj(*obj);
 	if (!obj)
 		return NULL;
 
@@ -550,7 +554,7 @@ static struct klp_func *klp_alloc_func_nop(struct klp_func *old_func,
 {
 	struct klp_func *func;
 
-	func = kzalloc(sizeof(*func), GFP_KERNEL);
+	func = kzalloc_obj(*func);
 	if (!func)
 		return NULL;
 
@@ -601,9 +605,12 @@ static int klp_add_object_nops(struct klp_patch *patch,
 }
 
 /*
- * Add 'nop' functions which simply return to the caller to run
- * the original function. The 'nop' functions are added to a
- * patch to facilitate a 'replace' mode.
+ * Add 'nop' functions which simply return to the caller to run the
+ * original function.
+ *
+ * They are added only when the atomic replace mode is used and only for
+ * functions which are currently livepatched but are no longer included
+ * in the new livepatch.
  */
 static int klp_add_nops(struct klp_patch *patch)
 {
@@ -1349,6 +1356,25 @@ void klp_module_going(struct module *mod)
 	mutex_unlock(&klp_mutex);
 }
 
+void *klp_find_section_by_name(const struct module *mod, const char *name,
+			       size_t *sec_size)
+{
+	struct klp_modinfo *info = mod->klp_info;
+
+	for (int i = 1; i < info->hdr.e_shnum; i++) {
+		Elf_Shdr *shdr = &info->sechdrs[i];
+
+		if (!strcmp(info->secstrings + shdr->sh_name, name)) {
+			*sec_size = shdr->sh_size;
+			return (void *)shdr->sh_addr;
+		}
+	}
+
+	*sec_size = 0;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(klp_find_section_by_name);
+
 static int __init klp_init(void)
 {
 	klp_root_kobj = kobject_create_and_add("livepatch", kernel_kobj);