aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2009-07-23 12:01:22 +0800
committerSteven Rostedt <rostedt@goodmis.org>2009-07-23 20:54:40 -0400
commit75e33751ca8bbb72dd6f1a74d2810ddc8cbe4bdf (patch)
tree35402f5e41b3e823ceed21ee535045f39cd5465a
parent8e068542a8d9efec55126284d2f5cb32f003d507 (diff)
downloadlinux-2.6.38-lt-ux500-75e33751ca8bbb72dd6f1a74d2810ddc8cbe4bdf.tar.gz
tracing/ksym_tracer: support quick clear for ksym_trace_filter -- v2
It's rather boring to clear symbol one by one in ksym_trace_filter file, so, this patch will let ksym_trace_filter file support quickly clear all break points. We can write "0" to this file and it will clear all symbols for example: # cat ksym_trace_filter ksym_filter_head:rw- global_trace:rw- # echo 0 > ksym_trace_filter # cat ksym_trace_filter # Changelog v1->v2: Add other ways to clear all breakpoints by writing NULL or "*:---" to ksym_trace_filter file base on K.Prasad's suggestion Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> LKML-Reference: <4A67E092.3080202@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_ksym.c53
1 files changed, 35 insertions, 18 deletions
diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c
index cd5cb656c3d..2fde875ead4 100644
--- a/kernel/trace/trace_ksym.c
+++ b/kernel/trace/trace_ksym.c
@@ -163,8 +163,6 @@ static int parse_ksym_trace_str(char *input_string, char **ksymname,
{
int ret;
- strstrip(input_string);
-
*ksymname = strsep(&input_string, ":");
*addr = kallsyms_lookup_name(*ksymname);
@@ -262,6 +260,25 @@ static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf,
return cnt;
}
+static void __ksym_trace_reset(void)
+{
+ struct trace_ksym *entry;
+ struct hlist_node *node, *node1;
+
+ mutex_lock(&ksym_tracer_mutex);
+ hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head,
+ ksym_hlist) {
+ unregister_kernel_hw_breakpoint(entry->ksym_hbp);
+ ksym_filter_entry_count--;
+ hlist_del_rcu(&(entry->ksym_hlist));
+ synchronize_rcu();
+ kfree(entry->ksym_hbp->info.name);
+ kfree(entry->ksym_hbp);
+ kfree(entry);
+ }
+ mutex_unlock(&ksym_tracer_mutex);
+}
+
static ssize_t ksym_trace_filter_write(struct file *file,
const char __user *buffer,
size_t count, loff_t *ppos)
@@ -282,6 +299,21 @@ static ssize_t ksym_trace_filter_write(struct file *file,
}
input_string[count] = '\0';
+ strstrip(input_string);
+
+ /*
+ * Clear all breakpoints if:
+ * 1: echo > ksym_trace_filter
+ * 2: echo 0 > ksym_trace_filter
+ * 3: echo "*:---" > ksym_trace_filter
+ */
+ if (!input_string[0] || !strcmp(input_string, "0") ||
+ !strcmp(input_string, "*:---")) {
+ __ksym_trace_reset();
+ kfree(input_string);
+ return count;
+ }
+
ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr);
if (ret < 0) {
kfree(input_string);
@@ -341,23 +373,8 @@ static const struct file_operations ksym_tracing_fops = {
static void ksym_trace_reset(struct trace_array *tr)
{
- struct trace_ksym *entry;
- struct hlist_node *node, *node1;
-
ksym_tracing_enabled = 0;
-
- mutex_lock(&ksym_tracer_mutex);
- hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head,
- ksym_hlist) {
- unregister_kernel_hw_breakpoint(entry->ksym_hbp);
- ksym_filter_entry_count--;
- hlist_del_rcu(&(entry->ksym_hlist));
- synchronize_rcu();
- kfree(entry->ksym_hbp->info.name);
- kfree(entry->ksym_hbp);
- kfree(entry);
- }
- mutex_unlock(&ksym_tracer_mutex);
+ __ksym_trace_reset();
}
static int ksym_trace_init(struct trace_array *tr)