summaryrefslogtreecommitdiff
path: root/kernel/trace
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c109
-rw-r--r--kernel/trace/trace.h7
-rw-r--r--kernel/trace/trace_events.c110
3 files changed, 124 insertions, 102 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7943e306cc7f..a8bb7485fd1d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -25,7 +25,7 @@
#include <linux/hardirq.h>
#include <linux/linkage.h>
#include <linux/uaccess.h>
-#include <linux/kprobes.h>
+#include <linux/vmalloc.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/percpu.h>
@@ -319,6 +319,12 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec,
return 0;
}
+void trace_free_pid_list(struct trace_pid_list *pid_list)
+{
+ vfree(pid_list->pids);
+ kfree(pid_list);
+}
+
/**
* trace_find_filtered_pid - check if a pid exists in a filtered_pid list
* @filtered_pids: The list of pids to check
@@ -468,6 +474,107 @@ int trace_pid_show(struct seq_file *m, void *v)
return 0;
}
+/* 128 should be much more than enough */
+#define PID_BUF_SIZE 127
+
+int trace_pid_write(struct trace_pid_list *filtered_pids,
+ struct trace_pid_list **new_pid_list,
+ const char __user *ubuf, size_t cnt)
+{
+ struct trace_pid_list *pid_list;
+ struct trace_parser parser;
+ unsigned long val;
+ int nr_pids = 0;
+ ssize_t read = 0;
+ ssize_t ret = 0;
+ loff_t pos;
+ pid_t pid;
+
+ if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
+ return -ENOMEM;
+
+ /*
+ * Always recreate a new array. The write is an all or nothing
+ * operation. Always create a new array when adding new pids by
+ * the user. If the operation fails, then the current list is
+ * not modified.
+ */
+ pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
+ if (!pid_list)
+ return -ENOMEM;
+
+ pid_list->pid_max = READ_ONCE(pid_max);
+
+ /* Only truncating will shrink pid_max */
+ if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
+ pid_list->pid_max = filtered_pids->pid_max;
+
+ pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
+ if (!pid_list->pids) {
+ kfree(pid_list);
+ return -ENOMEM;
+ }
+
+ if (filtered_pids) {
+ /* copy the current bits to the new max */
+ pid = find_first_bit(filtered_pids->pids,
+ filtered_pids->pid_max);
+ while (pid < filtered_pids->pid_max) {
+ set_bit(pid, pid_list->pids);
+ pid = find_next_bit(filtered_pids->pids,
+ filtered_pids->pid_max,
+ pid + 1);
+ nr_pids++;
+ }
+ }
+
+ while (cnt > 0) {
+
+ pos = 0;
+
+ ret = trace_get_user(&parser, ubuf, cnt, &pos);
+ if (ret < 0 || !trace_parser_loaded(&parser))
+ break;
+
+ read += ret;
+ ubuf += ret;
+ cnt -= ret;
+
+ parser.buffer[parser.idx] = 0;
+
+ ret = -EINVAL;
+ if (kstrtoul(parser.buffer, 0, &val))
+ break;
+ if (val >= pid_list->pid_max)
+ break;
+
+ pid = (pid_t)val;
+
+ set_bit(pid, pid_list->pids);
+ nr_pids++;
+
+ trace_parser_clear(&parser);
+ ret = 0;
+ }
+ trace_parser_put(&parser);
+
+ if (ret < 0) {
+ trace_free_pid_list(pid_list);
+ return ret;
+ }
+
+ if (!nr_pids) {
+ /* Cleared the list of pids */
+ trace_free_pid_list(pid_list);
+ read = ret;
+ pid_list = NULL;
+ }
+
+ *new_pid_list = pid_list;
+
+ return read;
+}
+
static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
{
u64 ts;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 45442d5842f2..a4dce1ef9e03 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -629,6 +629,9 @@ extern unsigned long nsecs_to_usecs(unsigned long nsecs);
extern unsigned long tracing_thresh;
/* PID filtering */
+
+extern int pid_max;
+
bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
pid_t search_pid);
bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
@@ -639,6 +642,10 @@ void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
int trace_pid_show(struct seq_file *m, void *v);
+void trace_free_pid_list(struct trace_pid_list *pid_list);
+int trace_pid_write(struct trace_pid_list *filtered_pids,
+ struct trace_pid_list **new_pid_list,
+ const char __user *ubuf, size_t cnt);
#ifdef CONFIG_TRACER_MAX_TRACE
void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index fd831a972bae..fd449eb138cf 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -15,7 +15,6 @@
#include <linux/kthread.h>
#include <linux/tracefs.h>
#include <linux/uaccess.h>
-#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/sort.h>
@@ -499,9 +498,6 @@ static void ftrace_clear_events(struct trace_array *tr)
mutex_unlock(&event_mutex);
}
-/* Shouldn't this be in a header? */
-extern int pid_max;
-
static void
event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
{
@@ -634,8 +630,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
/* Wait till all users are no longer using pid filtering */
synchronize_sched();
- vfree(pid_list->pids);
- kfree(pid_list);
+ trace_free_pid_list(pid_list);
}
static void ftrace_clear_event_pids(struct trace_array *tr)
@@ -1587,13 +1582,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
struct trace_pid_list *filtered_pids = NULL;
struct trace_pid_list *pid_list;
struct trace_event_file *file;
- struct trace_parser parser;
- unsigned long val;
- loff_t this_pos;
- ssize_t read = 0;
- ssize_t ret = 0;
- pid_t pid;
- int nr_pids = 0;
+ ssize_t ret;
if (!cnt)
return 0;
@@ -1602,93 +1591,15 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
if (ret < 0)
return ret;
- if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
- return -ENOMEM;
-
mutex_lock(&event_mutex);
+
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
- /*
- * Always recreate a new array. The write is an all or nothing
- * operation. Always create a new array when adding new pids by
- * the user. If the operation fails, then the current list is
- * not modified.
- */
- pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
- if (!pid_list) {
- read = -ENOMEM;
- goto out;
- }
- pid_list->pid_max = READ_ONCE(pid_max);
- /* Only truncating will shrink pid_max */
- if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
- pid_list->pid_max = filtered_pids->pid_max;
- pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
- if (!pid_list->pids) {
- kfree(pid_list);
- read = -ENOMEM;
- goto out;
- }
- if (filtered_pids) {
- /* copy the current bits to the new max */
- pid = find_first_bit(filtered_pids->pids,
- filtered_pids->pid_max);
- while (pid < filtered_pids->pid_max) {
- set_bit(pid, pid_list->pids);
- pid = find_next_bit(filtered_pids->pids,
- filtered_pids->pid_max,
- pid + 1);
- nr_pids++;
- }
- }
-
- while (cnt > 0) {
-
- this_pos = 0;
-
- ret = trace_get_user(&parser, ubuf, cnt, &this_pos);
- if (ret < 0 || !trace_parser_loaded(&parser))
- break;
-
- read += ret;
- ubuf += ret;
- cnt -= ret;
-
- parser.buffer[parser.idx] = 0;
-
- ret = -EINVAL;
- if (kstrtoul(parser.buffer, 0, &val))
- break;
- if (val >= pid_list->pid_max)
- break;
-
- pid = (pid_t)val;
-
- set_bit(pid, pid_list->pids);
- nr_pids++;
-
- trace_parser_clear(&parser);
- ret = 0;
- }
- trace_parser_put(&parser);
-
- if (ret < 0) {
- vfree(pid_list->pids);
- kfree(pid_list);
- read = ret;
+ ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
+ if (ret < 0)
goto out;
- }
- if (!nr_pids) {
- /* Cleared the list of pids */
- vfree(pid_list->pids);
- kfree(pid_list);
- read = ret;
- if (!filtered_pids)
- goto out;
- pid_list = NULL;
- }
rcu_assign_pointer(tr->filtered_pids, pid_list);
list_for_each_entry(file, &tr->events, list) {
@@ -1697,10 +1608,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
if (filtered_pids) {
synchronize_sched();
-
- vfree(filtered_pids->pids);
- kfree(filtered_pids);
- } else {
+ trace_free_pid_list(filtered_pids);
+ } else if (pid_list) {
/*
* Register a probe that is called before all other probes
* to set ignore_pid if next or prev do not match.
@@ -1738,9 +1647,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
out:
mutex_unlock(&event_mutex);
- ret = read;
- if (read > 0)
- *ppos += read;
+ if (ret > 0)
+ *ppos += ret;
return ret;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-03 05:37:05 +0000