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>

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>
Sergey Senozhatsky · Catalin Marinas
1 parent 008139d914
Showing 1 changed file with 39 additions and 0 deletions Side-by-side Diff
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++) {
...	...	@@ -162,6 +162,15 @@
162	162	/* flag set on newly allocated objects */
163	163	#define OBJECT_NEW (1 << 3)
164	164
	165	+/* number of bytes to print per line; must be 16 or 32 */
	166	+#define HEX_ROW_SIZE 16
	167	+/* number of bytes to print at a time (1, 2, 4, 8) */
	168	+#define HEX_GROUP_SIZE 1
	169	+/* include ASCII after the hex output */
	170	+#define HEX_ASCII 1
	171	+/* max number of lines to be printed */
	172	+#define HEX_MAX_LINES 2
	173	+
165	174	/* the list of all allocated objects */
166	175	static LIST_HEAD(object_list);
167	176	/* the list of gray-colored objects (see color_gray comment below) */
...	...	@@ -259,6 +268,35 @@
259	268	} while (0)
260	269
261	270	/*
	271	+ * Printing of the objects hex dump to the seq file. The number of lines to be
	272	+ * printed is limited to HEX_MAX_LINES to prevent seq file spamming. The
	273	+ * actual number of printed bytes depends on HEX_ROW_SIZE. It must be called
	274	+ * with the object->lock held.
	275	+ */
	276	+static void hex_dump_object(struct seq_file *seq,
	277	+ struct kmemleak_object *object)
	278	+{
	279	+ const u8 ptr = (const u8 )object->pointer;
	280	+ int i, len, remaining;
	281	+ unsigned char linebuf[HEX_ROW_SIZE * 5];
	282	+
	283	+ /* limit the number of lines to HEX_MAX_LINES */
	284	+ remaining = len =
	285	+ min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE));
	286	+
	287	+ seq_printf(seq, " hex dump (first %d bytes):\n", len);
	288	+ for (i = 0; i < len; i += HEX_ROW_SIZE) {
	289	+ int linelen = min(remaining, HEX_ROW_SIZE);
	290	+
	291	+ remaining -= HEX_ROW_SIZE;
	292	+ hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE,
	293	+ HEX_GROUP_SIZE, linebuf, sizeof(linebuf),
	294	+ HEX_ASCII);
	295	+ seq_printf(seq, " %s\n", linebuf);
	296	+ }
	297	+}
	298	+
	299	+/*
262	300	* Object colors, encoded with count and min_count:
263	301	* - white - orphan object, not enough references to it (count < min_count)
264	302	* - gray - not orphan, not marked as false positive (min_count == 0) or
...	...	@@ -308,6 +346,7 @@
308	346	object->pointer, object->size);
309	347	seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu\n",
310	348	object->comm, object->pid, object->jiffies);
	349	+ hex_dump_object(seq, object);
311	350	seq_printf(seq, " backtrace:\n");
312	351
313	352	for (i = 0; i < object->trace_len; i++) {