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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>
This commit is contained in:
Li Zefan 2009-07-07 13:52:36 +08:00 committed by Ingo Molnar
parent 9d22b53660
commit db59504d89
2 changed files with 22 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
kernel/trace/trace.h
View File

@ -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)

26
kernel/trace/trace_ksym.c
View File

@ -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 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs)
{
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 @@ void ksym_hbp_handler(struct hw_breakpoint *hbp, struct pt_regs *regs)
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 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
{
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 @@ static enum print_line_t ksym_trace_output(struct trace_iterator *iter)
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;