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>

1 files changed, 4 insertions, 9 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7d5cc37b8fca..ff1ef411a176 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -215,17 +215,12 @@ struct syscall_trace_exit {
 #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 @@ extern void __ftrace_bad_type(void);
                           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)