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_ksym.c b/kernel/trace/trace_ksym.c
index eef97e7..085ff05 100644
--- a/kernel/trace/trace_ksym.c
+++ b/kernel/trace/trace_ksym.c
@@ -37,6 +37,15 @@
#define KSYM_TRACER_OP_LEN 3 /* rw- */
#define KSYM_FILTER_ENTRY_LEN (KSYM_NAME_LEN + KSYM_TRACER_OP_LEN + 1)
+struct trace_ksym {
+ struct hw_breakpoint *ksym_hbp;
+ unsigned long ksym_addr;
+#ifdef CONFIG_PROFILE_KSYM_TRACER
+ unsigned long counter;
+#endif
+ struct hlist_node ksym_hlist;
+};
+
static struct trace_array *ksym_trace_array;
static unsigned int ksym_filter_entry_count;
@@ -71,7 +80,7 @@
{
struct ring_buffer_event *event;
struct trace_array *tr;
- struct trace_ksym *entry;
+ struct ksym_trace_entry *entry;
int pc;
if (!ksym_tracing_enabled)
@@ -85,11 +94,12 @@
if (!event)
return;
- entry = ring_buffer_event_data(event);
+ entry = ring_buffer_event_data(event);
+ entry->ip = instruction_pointer(regs);
+ entry->type = hbp->info.type;
strlcpy(entry->ksym_name, hbp->info.name, KSYM_SYMBOL_LEN);
- entry->ksym_hbp = hbp;
- entry->ip = instruction_pointer(regs);
- strlcpy(entry->p_name, current->comm, TASK_COMM_LEN);
+ strlcpy(entry->cmd, current->comm, TASK_COMM_LEN);
+
#ifdef CONFIG_PROFILE_KSYM_TRACER
ksym_collect_stats(hbp->info.address);
#endif /* CONFIG_PROFILE_KSYM_TRACER */
@@ -380,7 +390,7 @@
{
struct trace_entry *entry = iter->ent;
struct trace_seq *s = &iter->seq;
- struct trace_ksym *field;
+ struct ksym_trace_entry *field;
char str[KSYM_SYMBOL_LEN];
int ret;
@@ -389,12 +399,12 @@
trace_assign_type(field, entry);
- ret = trace_seq_printf(s, "%-15s %-5d %-3d %-20s ", field->p_name,
+ ret = trace_seq_printf(s, "%-15s %-5d %-3d %-20s ", field->cmd,
entry->pid, iter->cpu, field->ksym_name);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- switch (field->ksym_hbp->info.type) {
+ switch (field->type) {
case HW_BREAKPOINT_WRITE:
ret = trace_seq_printf(s, " W ");
break;