From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39199C433E2 for ; Tue, 14 Jul 2020 09:50:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 152E021D7A for ; Tue, 14 Jul 2020 09:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726785AbgGNJt7 (ORCPT ); Tue, 14 Jul 2020 05:49:59 -0400 Received: from mga05.intel.com ([192.55.52.43]:15581 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbgGNJt7 (ORCPT ); Tue, 14 Jul 2020 05:49:59 -0400 IronPort-SDR: r1Olfr0GnoXm6ueAh4gpt8wUB0OJuUZ1g2I7H1MoRa2kA+XAaJjrgQxMSfU+55yvecp4tVEDLV wqXPrzesVOXQ== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="233719746" X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="233719746" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 02:48:56 -0700 IronPort-SDR: akKlBNFCW4ZuH30XNmfFDJ/JqfwCotDaiI3gr2N16ft+Ek+Negj/NbNi6qG/3F2eQLTDTFlbPY on5RWH5j+GDw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,350,1589266800"; d="scan'208";a="459630798" Received: from rmarti11-mobl.ger.corp.intel.com (HELO localhost) ([10.252.54.57]) by orsmga005.jf.intel.com with ESMTP; 14 Jul 2020 02:48:48 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org Cc: Jarkko Sakkinen , Andi Kleen , Masami Hiramatsu , Jessica Yu , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Steven Rostedt , Ingo Molnar , live-patching@vger.kernel.org (open list:LIVE PATCHING) Subject: [PATCH v2 2/3] module: Add lock_modules() and unlock_modules() Date: Tue, 14 Jul 2020 12:45:37 +0300 Message-Id: <20200714094625.1443261-3-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200714094625.1443261-1-jarkko.sakkinen@linux.intel.com> References: <20200714094625.1443261-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add wrappers to take the modules "big lock" in order to encapsulate conditional compilation (CONFIG_MODULES) inside the wrapper. Cc: Andi Kleen Suggested-by: Masami Hiramatsu Signed-off-by: Jarkko Sakkinen --- include/linux/module.h | 15 ++++++++++ kernel/kprobes.c | 4 +-- kernel/livepatch/core.c | 8 ++--- kernel/module.c | 60 ++++++++++++++++++------------------- kernel/trace/trace_kprobe.c | 4 +-- 5 files changed, 53 insertions(+), 38 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 2e6670860d27..857b84bf9e90 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -902,4 +902,19 @@ static inline bool module_sig_ok(struct module *module) } #endif /* CONFIG_MODULE_SIG */ +#ifdef CONFIG_MODULES +static inline void lock_modules(void) +{ + mutex_lock(&module_mutex); +} + +static inline void unlock_modules(void) +{ + mutex_unlock(&module_mutex); +} +#else +static inline void lock_modules(void) { } +static inline void unlock_modules(void) { } +#endif + #endif /* _LINUX_MODULE_H */ diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d1c354ec89de..bbe3423cb2b8 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -564,7 +564,7 @@ static void kprobe_optimizer(struct work_struct *work) cpus_read_lock(); mutex_lock(&text_mutex); /* Lock modules while optimizing kprobes */ - mutex_lock(&module_mutex); + lock_modules(); /* * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) @@ -589,7 +589,7 @@ static void kprobe_optimizer(struct work_struct *work) /* Step 4: Free cleaned kprobes after quiesence period */ do_free_cleaned_kprobes(); - mutex_unlock(&module_mutex); + unlock_modules(); mutex_unlock(&text_mutex); cpus_read_unlock(); diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index f76fdb925532..d9d9d4973e6b 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -57,7 +57,7 @@ static void klp_find_object_module(struct klp_object *obj) if (!klp_is_module(obj)) return; - mutex_lock(&module_mutex); + lock_modules(); /* * We do not want to block removal of patched modules and therefore * we do not take a reference here. The patches are removed by @@ -74,7 +74,7 @@ static void klp_find_object_module(struct klp_object *obj) if (mod && mod->klp_alive) obj->mod = mod; - mutex_unlock(&module_mutex); + unlock_modules(); } static bool klp_initialized(void) @@ -163,12 +163,12 @@ static int klp_find_object_symbol(const char *objname, const char *name, .pos = sympos, }; - mutex_lock(&module_mutex); + lock_modules(); if (objname) module_kallsyms_on_each_symbol(klp_find_callback, &args); else kallsyms_on_each_symbol(klp_find_callback, &args); - mutex_unlock(&module_mutex); + unlock_modules(); /* * Ensure an address was found. If sympos is 0, ensure symbol is unique; diff --git a/kernel/module.c b/kernel/module.c index bdb3773f3668..3c7001cf754c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -895,7 +895,7 @@ static void module_unload_free(struct module *mod) { struct module_use *use, *tmp; - mutex_lock(&module_mutex); + lock_modules(); list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { struct module *i = use->target; pr_debug("%s unusing %s\n", mod->name, i->name); @@ -904,7 +904,7 @@ static void module_unload_free(struct module *mod) list_del(&use->target_list); kfree(use); } - mutex_unlock(&module_mutex); + unlock_modules(); } #ifdef CONFIG_MODULE_FORCE_UNLOAD @@ -1024,7 +1024,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, if (ret != 0) goto out; - mutex_unlock(&module_mutex); + unlock_modules(); /* Final destruction now no one is using it. */ if (mod->exit != NULL) mod->exit(); @@ -1043,7 +1043,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, wake_up_all(&module_wq); return 0; out: - mutex_unlock(&module_mutex); + unlock_modules(); return ret; } @@ -1448,7 +1448,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, * in the wait_event_interruptible(), which is harmless. */ sched_annotate_sleep(); - mutex_lock(&module_mutex); + lock_modules(); sym = find_symbol(name, &owner, &crc, !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); if (!sym) @@ -1475,7 +1475,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, /* We must make copy under the lock if we failed to get ref. */ strncpy(ownername, module_name(owner), MODULE_NAME_LEN); unlock: - mutex_unlock(&module_mutex); + unlock_modules(); return sym; } @@ -1727,10 +1727,10 @@ static void del_usage_links(struct module *mod) #ifdef CONFIG_MODULE_UNLOAD struct module_use *use; - mutex_lock(&module_mutex); + lock_modules(); list_for_each_entry(use, &mod->target_list, target_list) sysfs_remove_link(use->target->holders_dir, mod->name); - mutex_unlock(&module_mutex); + unlock_modules(); #endif } @@ -1740,14 +1740,14 @@ static int add_usage_links(struct module *mod) #ifdef CONFIG_MODULE_UNLOAD struct module_use *use; - mutex_lock(&module_mutex); + lock_modules(); list_for_each_entry(use, &mod->target_list, target_list) { ret = sysfs_create_link(use->target->holders_dir, &mod->mkobj.kobj, mod->name); if (ret) break; } - mutex_unlock(&module_mutex); + unlock_modules(); if (ret) del_usage_links(mod); #endif @@ -2158,9 +2158,9 @@ static void free_module(struct module *mod) /* We leave it in list to prevent duplicate loads, but make sure * that noone uses it while it's being deconstructed. */ - mutex_lock(&module_mutex); + lock_modules(); mod->state = MODULE_STATE_UNFORMED; - mutex_unlock(&module_mutex); + unlock_modules(); /* Remove dynamic debug info */ ddebug_remove_module(mod->name); @@ -2178,7 +2178,7 @@ static void free_module(struct module *mod) free_module_elf(mod); /* Now we can delete it from the lists */ - mutex_lock(&module_mutex); + lock_modules(); /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); mod_tree_remove(mod); @@ -2186,7 +2186,7 @@ static void free_module(struct module *mod) module_bug_cleanup(mod); /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ synchronize_rcu(); - mutex_unlock(&module_mutex); + unlock_modules(); /* This may be empty, but that's OK */ module_arch_freeing_init(mod); @@ -3474,10 +3474,10 @@ static bool finished_loading(const char *name) * in the wait_event_interruptible(), which is harmless. */ sched_annotate_sleep(); - mutex_lock(&module_mutex); + lock_modules(); mod = find_module_all(name, strlen(name), true); ret = !mod || mod->state == MODULE_STATE_LIVE; - mutex_unlock(&module_mutex); + unlock_modules(); return ret; } @@ -3589,7 +3589,7 @@ static noinline int do_init_module(struct module *mod) ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + mod->init_layout.size); - mutex_lock(&module_mutex); + lock_modules(); /* Drop initial reference. */ module_put(mod); trim_init_extable(mod); @@ -3621,7 +3621,7 @@ static noinline int do_init_module(struct module *mod) if (llist_add(&freeinit->node, &init_free_list)) schedule_work(&init_free_wq); - mutex_unlock(&module_mutex); + unlock_modules(); wake_up_all(&module_wq); return 0; @@ -3663,12 +3663,12 @@ static int add_unformed_module(struct module *mod) mod->state = MODULE_STATE_UNFORMED; again: - mutex_lock(&module_mutex); + lock_modules(); old = find_module_all(mod->name, strlen(mod->name), true); if (old != NULL) { if (old->state != MODULE_STATE_LIVE) { /* Wait in case it fails to load. */ - mutex_unlock(&module_mutex); + unlock_modules(); err = wait_event_interruptible(module_wq, finished_loading(mod->name)); if (err) @@ -3684,7 +3684,7 @@ static int add_unformed_module(struct module *mod) err = 0; out: - mutex_unlock(&module_mutex); + unlock_modules(); out_unlocked: return err; } @@ -3693,7 +3693,7 @@ static int complete_formation(struct module *mod, struct load_info *info) { int err; - mutex_lock(&module_mutex); + lock_modules(); /* Find duplicate symbols (must be called under lock). */ err = verify_exported_symbols(mod); @@ -3710,12 +3710,12 @@ static int complete_formation(struct module *mod, struct load_info *info) /* Mark state as coming so strong_try_module_get() ignores us, * but kallsyms etc. can see us. */ mod->state = MODULE_STATE_COMING; - mutex_unlock(&module_mutex); + unlock_modules(); return 0; out: - mutex_unlock(&module_mutex); + unlock_modules(); return err; } @@ -3913,9 +3913,9 @@ static int load_module(struct load_info *info, const char __user *uargs, klp_module_going(mod); bug_cleanup: /* module_bug_cleanup needs module_mutex protection */ - mutex_lock(&module_mutex); + lock_modules(); module_bug_cleanup(mod); - mutex_unlock(&module_mutex); + unlock_modules(); ddebug_cleanup: ftrace_release_mod(mod); @@ -3929,14 +3929,14 @@ static int load_module(struct load_info *info, const char __user *uargs, free_unload: module_unload_free(mod); unlink_mod: - mutex_lock(&module_mutex); + lock_modules(); /* Unlink carefully: kallsyms could be walking list. */ list_del_rcu(&mod->list); mod_tree_remove(mod); wake_up_all(&module_wq); /* Wait for RCU-sched synchronizing before releasing mod->list. */ synchronize_rcu(); - mutex_unlock(&module_mutex); + unlock_modules(); free_module: /* Free lock-classes; relies on the preceding sync_rcu() */ lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); @@ -4292,7 +4292,7 @@ static char *module_flags(struct module *mod, char *buf) /* Called by the /proc file system to return a list of modules. */ static void *m_start(struct seq_file *m, loff_t *pos) { - mutex_lock(&module_mutex); + lock_modules(); return seq_list_start(&modules, *pos); } @@ -4303,7 +4303,7 @@ static void *m_next(struct seq_file *m, void *p, loff_t *pos) static void m_stop(struct seq_file *m, void *p) { - mutex_unlock(&module_mutex); + unlock_modules(); } static int m_show(struct seq_file *m, void *p) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index aefb6065b508..710ec6a6aa8f 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -122,9 +122,9 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) if (!p) return true; *p = '\0'; - mutex_lock(&module_mutex); + lock_modules(); ret = !!find_module(tk->symbol); - mutex_unlock(&module_mutex); + unlock_modules(); *p = ':'; return ret; -- 2.25.1