4 files changed, 93 insertions, 20 deletions

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 52c0da4bdd18..bef3cda44c4c 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -1,6 +1,8 @@
 #ifndef _DYNAMIC_DEBUG_H
 #define _DYNAMIC_DEBUG_H
 
+#include <linux/jump_label.h>
+
 /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
  * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
  * use independent hash functions, to reduce the chance of false positives.
@@ -22,8 +24,6 @@ struct _ddebug {
         const char *function;
         const char *filename;
         const char *format;
-        char primary_hash;
-        char secondary_hash;
         unsigned int lineno:24;
         /*
          * The flags field controls the behaviour at the callsite.
@@ -33,6 +33,7 @@ struct _ddebug {
 #define _DPRINTK_FLAGS_PRINT   (1<<0)  /* printk() a message using the format */
 #define _DPRINTK_FLAGS_DEFAULT 0
         unsigned int flags:8;
+        char enabled;
 } __attribute__((aligned(8)));
 
 
@@ -42,33 +43,35 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 #if defined(CONFIG_DYNAMIC_DEBUG)
 extern int ddebug_remove_module(const char *mod_name);
 
-#define __dynamic_dbg_enabled(dd)  ({        \
-        int __ret = 0;                                                       \
-        if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) &&        \
-                        (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2))))   \
-                                if (unlikely(dd.flags))                      \
-                                        __ret = 1;                           \
-        __ret; })
-
 #define dynamic_pr_debug(fmt, ...) do {                                 \
+        __label__ do_printk;                                            \
+        __label__ out;                                                  \
         static struct _ddebug descriptor                                \
         __used                                                          \
         __attribute__((section("__verbose"), aligned(8))) =             \
-        { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH,  \
-                DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT };        \
-        if (__dynamic_dbg_enabled(descriptor))                          \
-                printk(KERN_DEBUG pr_fmt(fmt),  ##__VA_ARGS__);         \
+        { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,            \
+                _DPRINTK_FLAGS_DEFAULT };                               \
+        JUMP_LABEL(&descriptor.enabled, do_printk);                     \
+        goto out;                                                       \
+do_printk:                                                              \
+        printk(KERN_DEBUG pr_fmt(fmt),  ##__VA_ARGS__);                 \
+out:    ;                                                               \
         } while (0)
 
 
 #define dynamic_dev_dbg(dev, fmt, ...) do {                             \
+        __label__ do_printk;                                            \
+        __label__ out;                                                  \
         static struct _ddebug descriptor                                \
         __used                                                          \
         __attribute__((section("__verbose"), aligned(8))) =             \
-        { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH,  \
-                DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT };        \
-        if (__dynamic_dbg_enabled(descriptor))                          \
-                dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);        \
+        { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__,            \
+                _DPRINTK_FLAGS_DEFAULT };                               \
+        JUMP_LABEL(&descriptor.enabled, do_printk);                     \
+        goto out;                                                       \
+do_printk:                                                              \
+        dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__);                \
+out:    ;                                                               \
         } while (0)
 
 #else
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
new file mode 100644
index 000000000000..b72cd9f92c2e
--- /dev/null
+++ b/include/linux/jump_label.h
@@ -0,0 +1,64 @@
+#ifndef _LINUX_JUMP_LABEL_H
+#define _LINUX_JUMP_LABEL_H
+
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_HAVE_ARCH_JUMP_LABEL)
+# include <asm/jump_label.h>
+# define HAVE_JUMP_LABEL
+#endif
+
+enum jump_label_type {
+        JUMP_LABEL_ENABLE,
+        JUMP_LABEL_DISABLE
+};
+
+struct module;
+
+#ifdef HAVE_JUMP_LABEL
+
+extern struct jump_entry __start___jump_table[];
+extern struct jump_entry __stop___jump_table[];
+
+extern void arch_jump_label_transform(struct jump_entry *entry,
+                                 enum jump_label_type type);
+extern void arch_jump_label_text_poke_early(jump_label_t addr);
+extern void jump_label_update(unsigned long key, enum jump_label_type type);
+extern void jump_label_apply_nops(struct module *mod);
+extern int jump_label_text_reserved(void *start, void *end);
+
+#define enable_jump_label(key) \
+        jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE);
+
+#define disable_jump_label(key) \
+        jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE);
+
+#else
+
+#define JUMP_LABEL(key, label)                  \
+do {                                            \
+        if (unlikely(*key))                     \
+                goto label;                     \
+} while (0)
+
+#define enable_jump_label(cond_var)     \
+do {                                    \
+       *(cond_var) = 1;                 \
+} while (0)
+
+#define disable_jump_label(cond_var)    \
+do {                                    \
+       *(cond_var) = 0;                 \
+} while (0)
+
+static inline int jump_label_apply_nops(struct module *mod)
+{
+        return 0;
+}
+
+static inline int jump_label_text_reserved(void *start, void *end)
+{
+        return 0;
+}
+
+#endif
+
+#endif
diff --git a/include/linux/module.h b/include/linux/module.h
index 8a6b9fdc7ffa..403ac26023ce 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -350,7 +350,10 @@ struct module
         struct tracepoint *tracepoints;
         unsigned int num_tracepoints;
 #endif
-
+#ifdef HAVE_JUMP_LABEL
+        struct jump_entry *jump_entries;
+        unsigned int num_jump_entries;
+#endif
 #ifdef CONFIG_TRACING
         const char **trace_bprintk_fmt_start;
         unsigned int num_trace_bprintk_fmt;
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 103d1b61aacb..a4a90b6726ce 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/rcupdate.h>
+#include <linux/jump_label.h>
 
 struct module;
 struct tracepoint;
@@ -145,7 +146,9 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin,
         extern struct tracepoint __tracepoint_##name;                   \
         static inline void trace_##name(proto)                          \
         {                                                               \
-                if (unlikely(__tracepoint_##name.state))                \
+                JUMP_LABEL(&__tracepoint_##name.state, do_trace);       \
+                return;                                                 \
+do_trace:                                                               \
                         __DO_TRACE(&__tracepoint_##name,                \
                                 TP_PROTO(data_proto),                   \
                                 TP_ARGS(data_args));                    \