The patch titled
Subject: mm: use stack_depot for recording kmemleak's backtrace
has been added to the -mm mm-unstable branch. Its filename is
mm-use-stack_depot-for-recording-kmemleaks-backtrace.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-stack_depot-for-recording-kmemleaks-backtrace.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Subject: mm: use stack_depot for recording kmemleak's backtrace
Date: Thu, 27 Oct 2022 17:50:24 +0800
Using stack_depot to record kmemleak's backtrace which has been
implemented on slub for reducing redundant information.
Link: https://lkml.kernel.org/r/1666864224-27541-1-git-send-email-zhaoyang.huang@xxxxxxxxxx
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
Cc: 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>
---
--- a/mm/kmemleak.c~mm-use-stack_depot-for-recording-kmemleaks-backtrace
+++ a/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 */
@@ -346,8 +346,11 @@ static void print_unreferenced(struct se
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);
warn_or_seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu (age %d.%03ds)\n",
@@ -356,10 +359,10 @@ static void print_unreferenced(struct se
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];
- warn_or_seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
- }
+ for (i = 0; i < nr_entries; i++) {
+ void *ptr = (void *)entries[i];
+ warn_or_seq_printf(seq, " [<%p>] %pS\n", ptr, ptr);
+ }
}
/*
@@ -378,7 +381,8 @@ static void dump_object_info(struct kmem
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);
}
/*
@@ -591,6 +595,27 @@ static struct kmemleak_object *find_and_
return object;
}
+#ifdef CONFIG_STACKDEPOT
+static noinline depot_stack_handle_t set_track_prepare(void)
+{
+ 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;
+}
+#else
+static inline depot_stack_handle_t set_track_prepare(void)
+{
+ return 0;
+}
+#endif
+
/*
* Save stack trace to the given array of MAX_TRACE size.
*/
@@ -653,7 +678,7 @@ static void __create_object(unsigned lon
}
/* kernel backtrace */
- object->trace_len = __save_stack_trace(object->trace);
+ object->trace_handle = set_track_prepare();
raw_spin_lock_irqsave(&kmemleak_lock, flags);
@@ -692,7 +717,6 @@ static void __create_object(unsigned lon
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);
@@ -1091,7 +1115,7 @@ void __ref kmemleak_update_trace(const v
}
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);
@@ -2084,6 +2108,7 @@ 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);
_
Patches currently in -mm which might be from zhaoyang.huang@xxxxxxxxxx are
mm-use-stack_depot-for-recording-kmemleaks-backtrace.patch
