Three changes here: 1. Shorter variable names in arch/arc/kernel/unwind.c:unwind_add_table, to make it easier to read. 2. Rewrite free_mod_mem() so it is more obvious that MOD_DATA need to be freed last. 3. Clean up the use of CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC. Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Signed-off-by: Song Liu <song@xxxxxxxxxx> --- This is the follow up patch on top of [1]. I would recommend fold this into [1]. [1] https://lore.kernel.org/linux-modules/20230207002802.2514802-1-song@xxxxxxxxxx/T/#u --- arch/arc/kernel/unwind.c | 15 ++++------ kernel/module/main.c | 61 +++++++++++----------------------------- 2 files changed, 22 insertions(+), 54 deletions(-) diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c index 933451f4494f..9270d0a713c3 100644 --- a/arch/arc/kernel/unwind.c +++ b/arch/arc/kernel/unwind.c @@ -369,8 +369,8 @@ void *unwind_add_table(struct module *module, const void *table_start, unsigned long table_size) { struct unwind_table *table; - struct module_memory *mod_mem_core_text; - struct module_memory *mod_mem_init_text; + struct module_memory *core_text; + struct module_memory *init_text; if (table_size <= 0) return NULL; @@ -379,14 +379,11 @@ void *unwind_add_table(struct module *module, const void *table_start, if (!table) return NULL; - mod_mem_core_text = &module->mem[MOD_TEXT]; - mod_mem_init_text = &module->mem[MOD_INIT_TEXT]; + core_text = &module->mem[MOD_TEXT]; + init_text = &module->mem[MOD_INIT_TEXT]; - init_unwind_table(table, module->name, - mod_mem_core_text->base, mod_mem_core_text->size, - mod_mem_init_text->base, mod_mem_init_text->size, - table_start, table_size, - NULL, 0); + init_unwind_table(table, module->name, core_text->base, core_text->size, + init_text->base, init_text->size, table_start, table_size, NULL, 0); init_unwind_hdr(table, unw_hdr_alloc); diff --git a/kernel/module/main.c b/kernel/module/main.c index c598f11e7016..2724bc1b9a90 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -927,26 +927,17 @@ static ssize_t store_uevent(struct module_attribute *mattr, struct module_attribute module_uevent = __ATTR(uevent, 0200, NULL, store_uevent); -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC - -static ssize_t show_coresize(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - return sprintf(buffer, "%u\n", mk->mod->mem[MOD_TEXT].size); -} - -#else - static ssize_t show_coresize(struct module_attribute *mattr, struct module_kobject *mk, char *buffer) { - unsigned int size = 0; + unsigned int size = mk->mod->mem[MOD_TEXT].size; - for_class_mod_mem_type(type, core) - size += mk->mod->mem[type].size; + if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) { + for_class_mod_mem_type(type, core_data) + size += mk->mod->mem[type].size; + } return sprintf(buffer, "%u\n", size); } -#endif static struct module_attribute modinfo_coresize = __ATTR(coresize, 0444, show_coresize, NULL); @@ -1170,17 +1161,11 @@ void __weak module_arch_freeing_init(struct module *mod) { } -#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC static bool mod_mem_use_vmalloc(enum mod_mem_type type) { - return mod_mem_type_is_core_data(type); -} -#else -static bool mod_mem_use_vmalloc(enum mod_mem_type type) -{ - return false; + return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) && + mod_mem_type_is_core_data(type); } -#endif static void *module_memory_alloc(unsigned int size, enum mod_mem_type type) { @@ -1199,34 +1184,21 @@ static void module_memory_free(void *ptr, enum mod_mem_type type) static void free_mod_mem(struct module *mod) { - /* free the memory in the right order to avoid use-after-free */ - static enum mod_mem_type mod_mem_free_order[MOD_MEM_NUM_TYPES] = { - /* first free init sections */ - MOD_INIT_TEXT, - MOD_INIT_DATA, - MOD_INIT_RODATA, - - /* then core sections, except rw data */ - MOD_TEXT, - MOD_RODATA, - MOD_RO_AFTER_INIT, - - /* rw data need to be freed last, as it hosts mod */ - MOD_DATA, - }; - int i; - - BUILD_BUG_ON(ARRAY_SIZE(mod_mem_free_order) != MOD_MEM_NUM_TYPES); - - for (i = 0; i < MOD_MEM_NUM_TYPES; i++) { - enum mod_mem_type type = mod_mem_free_order[i]; + for_each_mod_mem_type(type) { struct module_memory *mod_mem = &mod->mem[type]; + if (type == MOD_DATA) + continue; + /* Free lock-classes; relies on the preceding sync_rcu(). */ lockdep_free_key_range(mod_mem->base, mod_mem->size); if (mod_mem->size) module_memory_free(mod_mem->base, type); } + + /* MOD_DATA hosts mod, so free it at last */ + lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size); + module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA); } /* Free a module, remove from lists, etc. */ @@ -2211,8 +2183,7 @@ static int move_module(struct module *mod, struct load_info *info) if (!(shdr->sh_flags & SHF_ALLOC)) continue; - dest = mod->mem[type].base + - (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK); + dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK); if (shdr->sh_type != SHT_NOBITS) memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); -- 2.30.2
