From 383bf44d1a8b18de5c26ec2a48c6822681b50984 Mon Sep 17 00:00:00 2001 From: Miroslav Benes Date: Thu, 14 Jan 2016 11:35:53 +0100 Subject: livepatch: change the error message in asm/livepatch.h header files If anyone includes asm/livepatch.h when CONFIG_LIVEPATCH=n the build fails with the existing error message. Change it to something saner. [jkosina@suse.cz: fixed changelog typo spotted by Josh] Suggested-by: Andrew Morton Signed-off-by: Miroslav Benes Acked-by: Josh Poimboeuf Signed-off-by: Jiri Kosina diff --git a/arch/s390/include/asm/livepatch.h b/arch/s390/include/asm/livepatch.h index 7aa7991..a52b6cc 100644 --- a/arch/s390/include/asm/livepatch.h +++ b/arch/s390/include/asm/livepatch.h @@ -37,7 +37,7 @@ static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) regs->psw.addr = ip; } #else -#error Live patching support is disabled; check CONFIG_LIVEPATCH +#error Include linux/livepatch.h, not asm/livepatch.h #endif #endif diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h index 19c099a..e795f52 100644 --- a/arch/x86/include/asm/livepatch.h +++ b/arch/x86/include/asm/livepatch.h @@ -41,7 +41,7 @@ static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) regs->ip = ip; } #else -#error Live patching support is disabled; check CONFIG_LIVEPATCH +#error Include linux/livepatch.h, not asm/livepatch.h #endif #endif /* _ASM_X86_LIVEPATCH_H */ -- cgit v0.10.2 From 7dcd182bec271ab341b05b66b6006995795fc0e7 Mon Sep 17 00:00:00 2001 From: Jessica Yu Date: Tue, 16 Feb 2016 17:32:33 -0500 Subject: ftrace/module: remove ftrace module notifier Remove the ftrace module notifier in favor of directly calling ftrace_module_enable() and ftrace_release_mod() in the module loader. Hard-coding the function calls directly in the module loader removes dependence on the module notifier call chain and provides better visibility and control over what gets called when, which is important to kernel utilities such as livepatch. This fixes a notifier ordering issue in which the ftrace module notifier (and hence ftrace_module_enable()) for coming modules was being called after klp_module_notify(), which caused livepatch modules to initialize incorrectly. This patch removes dependence on the module notifier call chain in favor of hard coding the corresponding function calls in the module loader. This ensures that ftrace and livepatch code get called in the correct order on patch module load and unload. Fixes: 5156dca34a3e ("ftrace: Fix the race between ftrace and insmod") Signed-off-by: Jessica Yu Reviewed-by: Steven Rostedt Reviewed-by: Petr Mladek Acked-by: Rusty Russell Reviewed-by: Josh Poimboeuf Reviewed-by: Miroslav Benes Signed-off-by: Jiri Kosina diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 0639dcc..76dc15e 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -604,6 +604,7 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size); extern int skip_trace(unsigned long ip); extern void ftrace_module_init(struct module *mod); +extern void ftrace_module_enable(struct module *mod); extern void ftrace_release_mod(struct module *mod); extern void ftrace_disable_daemon(void); @@ -613,8 +614,9 @@ static inline int skip_trace(unsigned long ip) { return 0; } static inline int ftrace_force_update(void) { return 0; } static inline void ftrace_disable_daemon(void) { } static inline void ftrace_enable_daemon(void) { } -static inline void ftrace_release_mod(struct module *mod) {} -static inline void ftrace_module_init(struct module *mod) {} +static inline void ftrace_module_init(struct module *mod) { } +static inline void ftrace_module_enable(struct module *mod) { } +static inline void ftrace_release_mod(struct module *mod) { } static inline __init int register_ftrace_command(struct ftrace_func_command *cmd) { return -EINVAL; diff --git a/kernel/module.c b/kernel/module.c index 8358f46..b05d466 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -981,6 +981,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, mod->exit(); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + ftrace_release_mod(mod); + async_synchronize_full(); /* Store the name of the last unloaded module for diagnostic purposes */ @@ -3295,6 +3297,7 @@ fail: module_put(mod); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); + ftrace_release_mod(mod); free_module(mod); wake_up_all(&module_wq); return ret; @@ -3371,6 +3374,7 @@ static int complete_formation(struct module *mod, struct load_info *info) mod->state = MODULE_STATE_COMING; mutex_unlock(&module_mutex); + ftrace_module_enable(mod); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); return 0; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index eca592f..57a6eea 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4961,7 +4961,7 @@ void ftrace_release_mod(struct module *mod) mutex_unlock(&ftrace_lock); } -static void ftrace_module_enable(struct module *mod) +void ftrace_module_enable(struct module *mod) { struct dyn_ftrace *rec; struct ftrace_page *pg; @@ -5038,38 +5038,8 @@ void ftrace_module_init(struct module *mod) ftrace_process_locs(mod, mod->ftrace_callsites, mod->ftrace_callsites + mod->num_ftrace_callsites); } - -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct module *mod = data; - - switch (val) { - case MODULE_STATE_COMING: - ftrace_module_enable(mod); - break; - case MODULE_STATE_GOING: - ftrace_release_mod(mod); - break; - default: - break; - } - - return 0; -} -#else -static int ftrace_module_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - return 0; -} #endif /* CONFIG_MODULES */ -struct notifier_block ftrace_module_nb = { - .notifier_call = ftrace_module_notify, - .priority = INT_MIN, /* Run after anything that can remove kprobes */ -}; - void __init ftrace_init(void) { extern unsigned long __start_mcount_loc[]; @@ -5098,10 +5068,6 @@ void __init ftrace_init(void) __start_mcount_loc, __stop_mcount_loc); - ret = register_module_notifier(&ftrace_module_nb); - if (ret) - pr_warning("Failed to register trace ftrace module exit notifier\n"); - set_ftrace_early_filters(); return; -- cgit v0.10.2