struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
int *ent_cpu, u64 *ent_ts)
{
- return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+ /* __find_next_entry will reset ent_size */
+ int ent_size = iter->ent_size;
+ struct trace_entry *entry;
+
+ /*
+ * The __find_next_entry() may call peek_next_entry(), which may
+ * call ring_buffer_peek() that may make the contents of iter->ent
+ * undefined. Need to copy iter->ent now.
+ */
+ if (iter->ent && iter->ent != iter->temp) {
+ if (!iter->temp || iter->temp_size < iter->ent_size) {
+ kfree(iter->temp);
+ iter->temp = kmalloc(iter->ent_size, GFP_KERNEL);
+ if (!iter->temp)
+ return NULL;
+ }
+ memcpy(iter->temp, iter->ent, iter->ent_size);
+ iter->temp_size = iter->ent_size;
+ iter->ent = iter->temp;
+ }
+ entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);
+ /* Put back the original ent_size */
+ iter->ent_size = ent_size;
+
+ return entry;
}
/* Find the next real entry, and increment the iterator to the next entry */
goto release;
/*
+ * trace_find_next_entry() may need to save off iter->ent.
+ * It will place it into the iter->temp buffer. As most
+ * events are less than 128, allocate a buffer of that size.
+ * If one is greater, then trace_find_next_entry() will
+ * allocate a new buffer to adjust for the bigger iter->ent.
+ * It's not critical if it fails to get allocated here.
+ */
+ iter->temp = kmalloc(128, GFP_KERNEL);
+ if (iter->temp)
+ iter->temp_size = 128;
+
+ /*
* We make a copy of the current tracer to avoid concurrent
* changes on it while we are reading.
*/
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->trace);
+ kfree(iter->temp);
kfree(iter->buffer_iter);
release:
seq_release_private(inode, file);
mutex_destroy(&iter->mutex);
free_cpumask_var(iter->started);
+ kfree(iter->temp);
kfree(iter->trace);
kfree(iter->buffer_iter);
seq_release_private(inode, file);
int trace_print_lat_context(struct trace_iterator *iter)
{
+ struct trace_entry *entry, *next_entry;
struct trace_array *tr = iter->tr;
- /* trace_find_next_entry will reset ent_size */
- int ent_size = iter->ent_size;
struct trace_seq *s = &iter->seq;
- u64 next_ts;
- struct trace_entry *entry = iter->ent,
- *next_entry = trace_find_next_entry(iter, NULL,
- &next_ts);
unsigned long verbose = (tr->trace_flags & TRACE_ITER_VERBOSE);
+ u64 next_ts;
- /* Restore the original ent_size */
- iter->ent_size = ent_size;
-
+ next_entry = trace_find_next_entry(iter, NULL, &next_ts);
if (!next_entry)
next_ts = iter->ts;
+ /* trace_find_next_entry() may change iter->ent */
+ entry = iter->ent;
+
if (verbose) {
char comm[TASK_COMM_LEN];