From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Using stack_depot to record kmemleak's backtrace which has been implemented
on slub for reducing redundant information.
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: ke.wang <ke.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Zhaoyang Huang <huangzhaoyang@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
changes of v2: fix bugs of stack_depot_init related issue
changes of v3: have DEBUG_KMEMLEAK select STACK_DEPOT by default
remove unuse functions
---
---
lib/Kconfig.debug | 1 +
mm/kmemleak.c | 48 +++++++++++++++++++++++++++++-------------------
2 files changed, 30 insertions(+), 19 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index bcbe60d..0def8e0 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -717,6 +717,7 @@ config DEBUG_KMEMLEAK
select STACKTRACE if STACKTRACE_SUPPORT
select KALLSYMS
select CRC32
+ select STACKDEPOT
help
Say Y here if you want to enable the memory leak
detector. The memory allocation/freeing is traced in a way
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 1eddc01..cedc6f3 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -79,6 +79,7 @@
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/stacktrace.h>
+#include <linux/stackdepot.h>
#include <linux/cache.h>
#include <linux/percpu.h>
#include <linux/memblock.h>
@@ -159,8 +160,7 @@ struct kmemleak_object {
u32 checksum;
/* memory ranges to be scanned inside an object (empty for all) */
struct hlist_head area_list;
- unsigned long trace[MAX_TRACE];
- unsigned int trace_len;
+ depot_stack_handle_t trace_handle;
unsigned long jiffies; /* creation timestamp */
pid_t pid; /* pid of the current task */
char comm[TASK_COMM_LEN]; /* executable name */
@@ -343,21 +343,24 @@ static bool unreferenced_object(struct kmemleak_object *object)
* print_unreferenced function must be called with the object->lock held.
*/
static void print_unreferenced(struct seq_file *seq,
- struct kmemleak_object *object)
+ struct kmemleak_object *object)
{
int i;
+ unsigned long *entries;
+ unsigned int nr_entries;
unsigned int msecs_age = jiffies_to_msecs(jiffies - object->jiffies);
+ nr_entries = stack_depot_fetch(object->trace_handle, &entries);
warn_or_seq_printf(seq, "unreferenced object 0x%08lx (size %zu):\n",
- object->pointer, object->size);
+ object->pointer, object->size);
warn_or_seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
- object->comm, object->pid, object->jiffies,
- msecs_age / 1000, msecs_age % 1000);
+ object->comm, object->pid, object->jiffies,
+ msecs_age / 1000, msecs_age % 1000);
hex_dump_object(seq, object);
warn_or_seq_printf(seq, " backtrace:\n");
- for (i = 0; i < object->trace_len; i++) {
- void *ptr = (void *)object->trace[i];
+ for (i = 0; i < nr_entries; i++) {
+ void *ptr = (void *)entries[i];
warn_or_seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
}
}
@@ -370,15 +373,16 @@ static void print_unreferenced(struct seq_file *seq,
static void dump_object_info(struct kmemleak_object *object)
{
pr_notice("Object 0x%08lx (size %zu):\n",
- object->pointer, object->size);
+ object->pointer, object->size);
pr_notice(" comm \"%s\", pid %d, jiffies %lu\n",
- object->comm, object->pid, object->jiffies);
+ object->comm, object->pid, object->jiffies);
pr_notice(" min_count = %d\n", object->min_count);
pr_notice(" count = %d\n", object->count);
pr_notice(" flags = 0x%x\n", object->flags);
pr_notice(" checksum = %u\n", object->checksum);
pr_notice(" backtrace:\n");
- stack_trace_print(object->trace, object->trace_len, 4);
+ if (object->trace_handle)
+ stack_depot_print(object->trace_handle);
}
/*
@@ -591,12 +595,18 @@ static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali
return object;
}
-/*
- * Save stack trace to the given array of MAX_TRACE size.
- */
-static int __save_stack_trace(unsigned long *trace)
+static noinline depot_stack_handle_t set_track_prepare(void)
{
- return stack_trace_save(trace, MAX_TRACE, 2);
+ depot_stack_handle_t trace_handle;
+ unsigned long entries[MAX_TRACE];
+ unsigned int nr_entries;
+
+ if (!kmemleak_initialized)
+ return 0;
+ nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
+ trace_handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
+
+ return trace_handle;
}
/*
@@ -654,7 +664,7 @@ static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
}
/* kernel backtrace */
- object->trace_len = __save_stack_trace(object->trace);
+ object->trace_handle = set_track_prepare();
raw_spin_lock_irqsave(&kmemleak_lock, flags);
@@ -694,7 +704,6 @@ static struct kmemleak_object *__create_object(unsigned long ptr, size_t size,
rb_link_node(&object->rb_node, rb_parent, link);
rb_insert_color(&object->rb_node, is_phys ? &object_phys_tree_root :
&object_tree_root);
-
list_add_tail_rcu(&object->object_list, &object_list);
out:
raw_spin_unlock_irqrestore(&kmemleak_lock, flags);
@@ -1094,7 +1103,7 @@ void __ref kmemleak_update_trace(const void *ptr)
}
raw_spin_lock_irqsave(&object->lock, flags);
- object->trace_len = __save_stack_trace(object->trace);
+ object->trace_handle = set_track_prepare();
raw_spin_unlock_irqrestore(&object->lock, flags);
put_object(object);
@@ -2064,6 +2073,7 @@ void __init kmemleak_init(void)
if (kmemleak_error)
return;
+ stack_depot_init();
jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE);
jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000);
--
1.9.1
