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-rw-r--r--kernel/trace/trace_seq.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 9c90b3a7dce2..e5e299260d0c 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -403,3 +403,26 @@ int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
return 1;
}
EXPORT_SYMBOL(trace_seq_hex_dump);
+
+/*
+ * trace_seq_acquire - acquire seq buffer with size len
+ * @s: trace sequence descriptor
+ * @len: size of buffer to be acquired
+ *
+ * acquire buffer with size of @len from trace_seq for output usage,
+ * user can fill string into that buffer.
+ *
+ * Returns start address of acquired buffer.
+ *
+ * it allow multiple usage in one trace output function call.
+ */
+char *trace_seq_acquire(struct trace_seq *s, unsigned int len)
+{
+ char *ret = trace_seq_buffer_ptr(s);
+
+ if (!WARN_ON_ONCE(seq_buf_buffer_left(&s->seq) < len))
+ seq_buf_commit(&s->seq, len);
+
+ return ret;
+}
+EXPORT_SYMBOL(trace_seq_acquire);