Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

5 files changed, 77 insertions, 13 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d017c2c82c44..1ee417fcbfa5 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -109,12 +109,18 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
 static void ftrace_global_list_func(unsigned long ip,
                                     unsigned long parent_ip)
 {
-        struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+        struct ftrace_ops *op;
+
+        if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+                return;
 
+        trace_recursion_set(TRACE_GLOBAL_BIT);
+        op = rcu_dereference_raw(ftrace_global_list); /*see above*/
         while (op != &ftrace_list_end) {
                 op->func(ip, parent_ip);
                 op = rcu_dereference_raw(op->next); /*see above*/
         };
+        trace_recursion_clear(TRACE_GLOBAL_BIT);
 }
 
 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
@@ -1638,12 +1644,12 @@ static void ftrace_startup_enable(int command)
         ftrace_run_update_code(command);
 }
 
-static void ftrace_startup(struct ftrace_ops *ops, int command)
+static int ftrace_startup(struct ftrace_ops *ops, int command)
 {
         bool hash_enable = true;
 
         if (unlikely(ftrace_disabled))
-                return;
+                return -ENODEV;
 
         ftrace_start_up++;
         command |= FTRACE_ENABLE_CALLS;
@@ -1662,6 +1668,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command)
                 ftrace_hash_rec_enable(ops, 1);
 
         ftrace_startup_enable(command);
+
+        return 0;
 }
 
 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
@@ -2501,7 +2509,7 @@ static void __enable_ftrace_function_probe(void)
 
         ret = __register_ftrace_function(&trace_probe_ops);
         if (!ret)
-                ftrace_startup(&trace_probe_ops, 0);
+                ret = ftrace_startup(&trace_probe_ops, 0);
 
         ftrace_probe_registered = 1;
 }
@@ -3466,7 +3474,11 @@ device_initcall(ftrace_nodyn_init);
 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
 static inline void ftrace_startup_enable(int command) { }
 /* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command)   do { } while (0)
+# define ftrace_startup(ops, command)                   \
+        ({                                              \
+                (ops)->flags |= FTRACE_OPS_FL_ENABLED;  \
+                0;                                      \
+        })
 # define ftrace_shutdown(ops, command)  do { } while (0)
 # define ftrace_startup_sysctl()        do { } while (0)
 # define ftrace_shutdown_sysctl()       do { } while (0)
@@ -3484,6 +3496,10 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
 {
         struct ftrace_ops *op;
 
+        if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+                return;
+
+        trace_recursion_set(TRACE_INTERNAL_BIT);
         /*
          * Some of the ops may be dynamically allocated,
          * they must be freed after a synchronize_sched().
@@ -3496,6 +3512,7 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
                 op = rcu_dereference_raw(op->next);
         };
         preempt_enable_notrace();
+        trace_recursion_clear(TRACE_INTERNAL_BIT);
 }
 
 static void clear_ftrace_swapper(void)
@@ -3799,7 +3816,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
 
         ret = __register_ftrace_function(ops);
         if (!ret)
-                ftrace_startup(ops, 0);
+                ret = ftrace_startup(ops, 0);
 
 
  out_unlock:
@@ -4045,7 +4062,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         ftrace_graph_return = retfunc;
         ftrace_graph_entry = entryfunc;
 
-        ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+        ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
 
 out:
         mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0ef7b4b2a1f7..b0c7aa407943 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2216,7 +2216,7 @@ static noinline void trace_recursive_fail(void)
 
         printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:"
                     "HC[%lu]:SC[%lu]:NMI[%lu]\n",
-                    current->trace_recursion,
+                    trace_recursion_buffer(),
                     hardirq_count() >> HARDIRQ_SHIFT,
                     softirq_count() >> SOFTIRQ_SHIFT,
                     in_nmi());
@@ -2226,9 +2226,9 @@ static noinline void trace_recursive_fail(void)
 
 static inline int trace_recursive_lock(void)
 {
-        current->trace_recursion++;
+        trace_recursion_inc();
 
-        if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
+        if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH))
                 return 0;
 
         trace_recursive_fail();
@@ -2238,9 +2238,9 @@ static inline int trace_recursive_lock(void)
 
 static inline void trace_recursive_unlock(void)
 {
-        WARN_ON_ONCE(!current->trace_recursion);
+        WARN_ON_ONCE(!trace_recursion_buffer());
 
-        current->trace_recursion--;
+        trace_recursion_dec();
 }
 
 #else
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6b69c4bd306f..229f8591f61d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -784,4 +784,19 @@ extern const char *__stop___trace_bprintk_fmt[];
         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 #include "trace_entries.h"
 
+/* Only current can touch trace_recursion */
+#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
+#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
+
+/* Ring buffer has the 10 LSB bits to count */
+#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
+
+/* for function tracing recursion */
+#define TRACE_INTERNAL_BIT              (1<<11)
+#define TRACE_GLOBAL_BIT                (1<<12)
+
+#define trace_recursion_set(bit)        do { (current)->trace_recursion |= (bit); } while (0)
+#define trace_recursion_clear(bit)      do { (current)->trace_recursion &= ~(bit); } while (0)
+#define trace_recursion_test(bit)       ((current)->trace_recursion & (bit))
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 2fe110341359..686ec399f2a8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1657,7 +1657,12 @@ static struct ftrace_ops trace_ops __initdata  =
 
 static __init void event_trace_self_test_with_function(void)
 {
-        register_ftrace_function(&trace_ops);
+        int ret;
+        ret = register_ftrace_function(&trace_ops);
+        if (WARN_ON(ret < 0)) {
+                pr_info("Failed to enable function tracer for event tests\n");
+                return;
+        }
         pr_info("Running tests again, along with the function tracer\n");
         event_trace_self_tests();
         unregister_ftrace_function(&trace_ops);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cf535ccedc86..e37de492a9e1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -353,6 +353,33 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 }
 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 
+#if BITS_PER_LONG == 32
+const char *
+ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
+                         const struct trace_print_flags_u64 *symbol_array)
+{
+        int i;
+        const char *ret = p->buffer + p->len;
+
+        for (i = 0;  symbol_array[i].name; i++) {
+
+                if (val != symbol_array[i].mask)
+                        continue;
+
+                trace_seq_puts(p, symbol_array[i].name);
+                break;
+        }
+
+        if (!p->len)
+                trace_seq_printf(p, "0x%llx", val);
+
+        trace_seq_putc(p, 0);
+
+        return ret;
+}
+EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
+#endif
+
 const char *
 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 {