ksym_tracer: Extract trace entry from struct trace_ksym

struct trace_ksym is used as an entry in hbp list, and is also
used as trace_entry stored in ring buffer.

This is not necessary and is a waste of memory in ring buffer.

There is also a bug that dereferencing field->ksym_hbp in
ksym_trace_output() can be invalid.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A52E2A4.4050007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7d5cc37..ff1ef41 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -215,17 +215,12 @@
 #define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy"
 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 
-struct trace_ksym {
+struct ksym_trace_entry {
 	struct trace_entry	ent;
-	struct hw_breakpoint	*ksym_hbp;
-	unsigned long		ksym_addr;
 	unsigned long		ip;
-#ifdef CONFIG_PROFILE_KSYM_TRACER
-	unsigned long		counter;
-#endif
-	struct hlist_node	ksym_hlist;
+	unsigned char		type;
 	char			ksym_name[KSYM_NAME_LEN];
-	char			p_name[TASK_COMM_LEN];
+	char			cmd[TASK_COMM_LEN];
 };
 
 /*
@@ -343,7 +338,7 @@
 			  TRACE_SYSCALL_ENTER);				\
 		IF_ASSIGN(var, ent, struct syscall_trace_exit,		\
 			  TRACE_SYSCALL_EXIT);				\
-		IF_ASSIGN(var, ent, struct trace_ksym, TRACE_KSYM);	\
+		IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 		__ftrace_bad_type();					\
 	} while (0)