Merge tag 'v3.10.101' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / tracepoint.h

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 2f322c38bd4d61d01e63bb89d2fa134e9b809ae6..fe6f0b3fe49c75cc56e3560bbcee18325b55ae43 100644 (file)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -14,8 +14,11 @@
  * See the file COPYING for more details.
  */
 
+#include <linux/smp.h>
 #include <linux/errno.h>
 #include <linux/types.h>
+#include <linux/percpu.h>
+#include <linux/cpumask.h>
 #include <linux/rcupdate.h>
 #include <linux/static_key.h>
 
@@ -60,6 +63,12 @@ struct tp_module {
        unsigned int num_tracepoints;
        struct tracepoint * const *tracepoints_ptrs;
 };
+bool trace_module_has_bad_taint(struct module *mod);
+#else
+static inline bool trace_module_has_bad_taint(struct module *mod)
+{
+       return false;
+}
 #endif /* CONFIG_MODULES */
 
 struct tracepoint_iter {
@@ -145,8 +154,8 @@ static inline void tracepoint_synchronize_unregister(void)
                                TP_PROTO(data_proto),                   \
                                TP_ARGS(data_args),                     \
                                TP_CONDITION(cond),                     \
-                               rcu_idle_exit(),                        \
-                               rcu_idle_enter());                      \
+                               rcu_irq_enter(),                        \
+                               rcu_irq_exit());                        \
        }
 #else
 #define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
@@ -238,6 +247,50 @@ static inline void tracepoint_synchronize_unregister(void)
 
 #endif /* CONFIG_TRACEPOINTS */
 
+#ifdef CONFIG_TRACING
+/**
+ * tracepoint_string - register constant persistent string to trace system
+ * @str - a constant persistent string that will be referenced in tracepoints
+ *
+ * If constant strings are being used in tracepoints, it is faster and
+ * more efficient to just save the pointer to the string and reference
+ * that with a printf "%s" instead of saving the string in the ring buffer
+ * and wasting space and time.
+ *
+ * The problem with the above approach is that userspace tools that read
+ * the binary output of the trace buffers do not have access to the string.
+ * Instead they just show the address of the string which is not very
+ * useful to users.
+ *
+ * With tracepoint_string(), the string will be registered to the tracing
+ * system and exported to userspace via the debugfs/tracing/printk_formats
+ * file that maps the string address to the string text. This way userspace
+ * tools that read the binary buffers have a way to map the pointers to
+ * the ASCII strings they represent.
+ *
+ * The @str used must be a constant string and persistent as it would not
+ * make sense to show a string that no longer exists. But it is still fine
+ * to be used with modules, because when modules are unloaded, if they
+ * had tracepoints, the ring buffers are cleared too. As long as the string
+ * does not change during the life of the module, it is fine to use
+ * tracepoint_string() within a module.
+ */
+#define tracepoint_string(str)                                         \
+       ({                                                              \
+               static const char *___tp_str __tracepoint_string = str; \
+               ___tp_str;                                              \
+       })
+#define __tracepoint_string    __attribute__((section("__tracepoint_str")))
+#else
+/*
+ * tracepoint_string() is used to save the string address for userspace
+ * tracing tools. When tracing isn't configured, there's no need to save
+ * anything.
+ */
+# define tracepoint_string(str) str
+# define __tracepoint_string
+#endif
+
 /*
  * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
  * (void). "void" is a special value in a function prototype and can
@@ -253,15 +306,19 @@ static inline void tracepoint_synchronize_unregister(void)
  * "void *__data, proto" as the callback prototype.
  */
 #define DECLARE_TRACE_NOARGS(name)                                     \
-               __DECLARE_TRACE(name, void, , 1, void *__data, __data)
+       __DECLARE_TRACE(name, void, ,                                   \
+                       cpu_online(raw_smp_processor_id()),             \
+                       void *__data, __data)
 
 #define DECLARE_TRACE(name, proto, args)                               \
-               __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), 1,   \
-                               PARAMS(void *__data, proto),            \
-                               PARAMS(__data, args))
+       __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),              \
+                       cpu_online(raw_smp_processor_id()),             \
+                       PARAMS(void *__data, proto),                    \
+                       PARAMS(__data, args))
 
 #define DECLARE_TRACE_CONDITION(name, proto, args, cond)               \
-       __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
+       __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),              \
+                       cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
                        PARAMS(void *__data, proto),                    \
                        PARAMS(__data, args))