Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fixes from Jiri Kosina:
- regression (from 4.4) fix for ordering issue, introduced by an
earlier ftrace change, that broke live patching of modules.
The fix replaces the ftrace module notifier by direct call in order
to make the ordering guaranteed and well-defined. The patch, from
Jessica Yu, has been acked both by Steven and Rusty
- error message fix from Miroslav Benes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
ftrace/module: remove ftrace module notifier
livepatch: change the error message in asm/livepatch.h header files
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 @@
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 @@
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 */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 81de712..c2b340e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -603,6 +603,7 @@
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);
@@ -612,8 +613,9 @@
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 9537da3..794ebe8 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -984,6 +984,8 @@
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 */
@@ -3313,6 +3315,7 @@
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;
@@ -3389,6 +3392,7 @@
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 @@
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 @@
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 @@
__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;