kmemleak: Show where early_log issues come from
Based on initial patch by Steven Rostedt.
Early kmemleak warnings did not show where the actual kmemleak API had
been called from but rather just a backtrace to the kmemleak_init()
function. By having all early kmemleak logs record the stack_trace, we
can have kmemleak_init() write exactly where the problem occurred. This
patch adds the setting of the kmemleak_warning variable every time a
kmemleak warning is issued. The kmemleak_init() function checks this
variable during early log replaying and prints the log trace if there
was any warning.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index f3b2a00..8b528e3 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -196,7 +196,9 @@
static atomic_t kmemleak_initialized = ATOMIC_INIT(0);
/* enables or disables early logging of the memory operations */
static atomic_t kmemleak_early_log = ATOMIC_INIT(1);
-/* set if a fata kmemleak error has occurred */
+/* set if a kmemleak warning was issued */
+static atomic_t kmemleak_warning = ATOMIC_INIT(0);
+/* set if a fatal kmemleak error has occurred */
static atomic_t kmemleak_error = ATOMIC_INIT(0);
/* minimum and maximum address that may be valid pointers */
@@ -259,9 +261,10 @@
/*
* Print a warning and dump the stack trace.
*/
-#define kmemleak_warn(x...) do { \
- pr_warning(x); \
- dump_stack(); \
+#define kmemleak_warn(x...) do { \
+ pr_warning(x); \
+ dump_stack(); \
+ atomic_set(&kmemleak_warning, 1); \
} while (0)
/*
@@ -403,8 +406,8 @@
object = prio_tree_entry(node, struct kmemleak_object,
tree_node);
if (!alias && object->pointer != ptr) {
- pr_warning("Found object by alias at 0x%08lx\n", ptr);
- dump_stack();
+ kmemleak_warn("Found object by alias at 0x%08lx\n",
+ ptr);
dump_object_info(object);
object = NULL;
}
@@ -811,8 +814,7 @@
log->ptr = ptr;
log->size = size;
log->min_count = min_count;
- if (op_type == KMEMLEAK_ALLOC)
- log->trace_len = __save_stack_trace(log->trace);
+ log->trace_len = __save_stack_trace(log->trace);
crt_early_log++;
local_irq_restore(flags);
}
@@ -1659,6 +1661,17 @@
}
early_param("kmemleak", kmemleak_boot_config);
+static void __init print_log_trace(struct early_log *log)
+{
+ struct stack_trace trace;
+
+ trace.nr_entries = log->trace_len;
+ trace.entries = log->trace;
+
+ pr_notice("Early log backtrace:\n");
+ print_stack_trace(&trace, 2);
+}
+
/*
* Kmemleak initialization.
*/
@@ -1720,7 +1733,13 @@
kmemleak_no_scan(log->ptr);
break;
default:
- WARN_ON(1);
+ kmemleak_warn("Unknown early log operation: %d\n",
+ log->op_type);
+ }
+
+ if (atomic_read(&kmemleak_warning)) {
+ print_log_trace(log);
+ atomic_set(&kmemleak_warning, 0);
}
}
}