kmemleak: Printing of the objects hex dump
Introducing printing of the objects hex dump to the seq file.
The number of lines to be printed is limited to HEX_MAX_LINES
to prevent seq file spamming. The actual number of printed
bytes is less than or equal to (HEX_MAX_LINES * HEX_ROW_SIZE).
(slight adjustments by Catalin Marinas)
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 8172154..1d7645b 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -162,6 +162,15 @@
/* flag set on newly allocated objects */
#define OBJECT_NEW (1 << 3)
+/* number of bytes to print per line; must be 16 or 32 */
+#define HEX_ROW_SIZE 16
+/* number of bytes to print at a time (1, 2, 4, 8) */
+#define HEX_GROUP_SIZE 1
+/* include ASCII after the hex output */
+#define HEX_ASCII 1
+/* max number of lines to be printed */
+#define HEX_MAX_LINES 2
+
/* the list of all allocated objects */
static LIST_HEAD(object_list);
/* the list of gray-colored objects (see color_gray comment below) */
@@ -259,6 +268,35 @@
} while (0)
/*
+ * Printing of the objects hex dump to the seq file. The number of lines to be
+ * printed is limited to HEX_MAX_LINES to prevent seq file spamming. The
+ * actual number of printed bytes depends on HEX_ROW_SIZE. It must be called
+ * with the object->lock held.
+ */
+static void hex_dump_object(struct seq_file *seq,
+ struct kmemleak_object *object)
+{
+ const u8 *ptr = (const u8 *)object->pointer;
+ int i, len, remaining;
+ unsigned char linebuf[HEX_ROW_SIZE * 5];
+
+ /* limit the number of lines to HEX_MAX_LINES */
+ remaining = len =
+ min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE));
+
+ seq_printf(seq, " hex dump (first %d bytes):\n", len);
+ for (i = 0; i < len; i += HEX_ROW_SIZE) {
+ int linelen = min(remaining, HEX_ROW_SIZE);
+
+ remaining -= HEX_ROW_SIZE;
+ hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE,
+ HEX_GROUP_SIZE, linebuf, sizeof(linebuf),
+ HEX_ASCII);
+ seq_printf(seq, " %s\n", linebuf);
+ }
+}
+
+/*
* Object colors, encoded with count and min_count:
* - white - orphan object, not enough references to it (count < min_count)
* - gray - not orphan, not marked as false positive (min_count == 0) or
@@ -308,6 +346,7 @@
object->pointer, object->size);
seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu\n",
object->comm, object->pid, object->jiffies);
+ hex_dump_object(seq, object);
seq_printf(seq, " backtrace:\n");
for (i = 0; i < object->trace_len; i++) {
