3.10-stable patches

added patches:
	ftrace-module-hardcode-ftrace_module_init-call-into-load_module.patch

diff --git a/queue-3.10/ftrace-module-hardcode-ftrace_module_init-call-into-load_module.patch b/queue-3.10/ftrace-module-hardcode-ftrace_module_init-call-into-load_module.patch
new file mode 100644 (file)
index 0000000..3311917
--- /dev/null
+++ b/queue-3.10/ftrace-module-hardcode-ftrace_module_init-call-into-load_module.patch
@@ -0,0 +1,152 @@
+From a949ae560a511fe4e3adf48fa44fefded93e5c2b Mon Sep 17 00:00:00 2001
+From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
+Date: Thu, 24 Apr 2014 10:40:12 -0400
+Subject: ftrace/module: Hardcode ftrace_module_init() call into load_module()
+
+From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
+
+commit a949ae560a511fe4e3adf48fa44fefded93e5c2b upstream.
+
+A race exists between module loading and enabling of function tracer.
+
+       CPU 1                           CPU 2
+       -----                           -----
+  load_module()
+   module->state = MODULE_STATE_COMING
+
+                               register_ftrace_function()
+                                mutex_lock(&ftrace_lock);
+                                ftrace_startup()
+                                 update_ftrace_function();
+                                  ftrace_arch_code_modify_prepare()
+                                   set_all_module_text_rw();
+                                  <enables-ftrace>
+                                   ftrace_arch_code_modify_post_process()
+                                    set_all_module_text_ro();
+
+                               [ here all module text is set to RO,
+                                 including the module that is
+                                 loading!! ]
+
+   blocking_notifier_call_chain(MODULE_STATE_COMING);
+    ftrace_init_module()
+
+     [ tries to modify code, but it's RO, and fails!
+       ftrace_bug() is called]
+
+When this race happens, ftrace_bug() will produces a nasty warning and
+all of the function tracing features will be disabled until reboot.
+
+The simple solution is to treate module load the same way the core
+kernel is treated at boot. To hardcode the ftrace function modification
+of converting calls to mcount into nops. This is done in init/main.c
+there's no reason it could not be done in load_module(). This gives
+a better control of the changes and doesn't tie the state of the
+module to its notifiers as much. Ftrace is special, it needs to be
+treated as such.
+
+The reason this would work, is that the ftrace_module_init() would be
+called while the module is in MODULE_STATE_UNFORMED, which is ignored
+by the set_all_module_text_ro() call.
+
+Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com
+
+Reported-by: Takao Indoh <indou.takao@jp.fujitsu.com>
+Acked-by: Rusty Russell <rusty@rustcorp.com.au>
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/ftrace.h |    2 ++
+ kernel/module.c        |    3 +++
+ kernel/trace/ftrace.c  |   27 ++++-----------------------
+ 3 files changed, 9 insertions(+), 23 deletions(-)
+
+--- a/include/linux/ftrace.h
++++ b/include/linux/ftrace.h
+@@ -524,6 +524,7 @@ static inline int ftrace_modify_call(str
+ 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_disable_daemon(void);
+ extern void ftrace_enable_daemon(void);
+@@ -533,6 +534,7 @@ static inline int ftrace_force_update(vo
+ 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 int register_ftrace_command(struct ftrace_func_command *cmd)
+ {
+       return -EINVAL;
+--- a/kernel/module.c
++++ b/kernel/module.c
+@@ -3279,6 +3279,9 @@ static int load_module(struct load_info
+ 
+       dynamic_debug_setup(info->debug, info->num_debug);
+ 
++      /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
++      ftrace_module_init(mod);
++
+       /* Finally it's fully formed, ready to start executing. */
+       err = complete_formation(mod, info);
+       if (err)
+--- a/kernel/trace/ftrace.c
++++ b/kernel/trace/ftrace.c
+@@ -4222,16 +4222,11 @@ static void ftrace_init_module(struct mo
+       ftrace_process_locs(mod, start, end);
+ }
+ 
+-static int ftrace_module_notify_enter(struct notifier_block *self,
+-                                    unsigned long val, void *data)
++void ftrace_module_init(struct module *mod)
+ {
+-      struct module *mod = data;
+-
+-      if (val == MODULE_STATE_COMING)
+-              ftrace_init_module(mod, mod->ftrace_callsites,
+-                                 mod->ftrace_callsites +
+-                                 mod->num_ftrace_callsites);
+-      return 0;
++      ftrace_init_module(mod, mod->ftrace_callsites,
++                         mod->ftrace_callsites +
++                         mod->num_ftrace_callsites);
+ }
+ 
+ static int ftrace_module_notify_exit(struct notifier_block *self,
+@@ -4245,11 +4240,6 @@ static int ftrace_module_notify_exit(str
+       return 0;
+ }
+ #else
+-static int ftrace_module_notify_enter(struct notifier_block *self,
+-                                    unsigned long val, void *data)
+-{
+-      return 0;
+-}
+ static int ftrace_module_notify_exit(struct notifier_block *self,
+                                    unsigned long val, void *data)
+ {
+@@ -4257,11 +4247,6 @@ static int ftrace_module_notify_exit(str
+ }
+ #endif /* CONFIG_MODULES */
+ 
+-struct notifier_block ftrace_module_enter_nb = {
+-      .notifier_call = ftrace_module_notify_enter,
+-      .priority = INT_MAX,    /* Run before anything that can use kprobes */
+-};
+-
+ struct notifier_block ftrace_module_exit_nb = {
+       .notifier_call = ftrace_module_notify_exit,
+       .priority = INT_MIN,    /* Run after anything that can remove kprobes */
+@@ -4298,10 +4283,6 @@ void __init ftrace_init(void)
+                                 __start_mcount_loc,
+                                 __stop_mcount_loc);
+ 
+-      ret = register_module_notifier(&ftrace_module_enter_nb);
+-      if (ret)
+-              pr_warning("Failed to register trace ftrace module enter notifier\n");
+-
+       ret = register_module_notifier(&ftrace_module_exit_nb);
+       if (ret)
+               pr_warning("Failed to register trace ftrace module exit notifier\n");

diff --git a/queue-3.10/series b/queue-3.10/series
index c2948d6c2a827cb5f9a0dcacdd8199cfb284c47e..a50b6d1edc98629573d01f99e91e98c67dffc530 100644 (file)
--- a/queue-3.10/series
+++ b/queue-3.10/series
@@ -1,3 +1,4 @@
 futex-add-another-early-deadlock-detection-check.patch
 futex-prevent-attaching-to-kernel-threads.patch
 mips-dts-fix-missing-device_type-memory-property-in-memory-nodes.patch
+ftrace-module-hardcode-ftrace_module_init-call-into-load_module.patch