From nobody Tue Apr 7 03:34:21 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F3E2FA3743 for ; Sun, 30 Oct 2022 03:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229610AbiJ3Dnw (ORCPT ); Sat, 29 Oct 2022 23:43:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbiJ3Dnu (ORCPT ); Sat, 29 Oct 2022 23:43:50 -0400 Received: from SHSQR01.spreadtrum.com (unknown [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDEBB2A962 for ; Sat, 29 Oct 2022 20:43:47 -0700 (PDT) Received: from SHSend.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by SHSQR01.spreadtrum.com with ESMTPS id 29U3guO2084239 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NO); Sun, 30 Oct 2022 11:42:57 +0800 (CST) (envelope-from zhaoyang.huang@unisoc.com) Received: from bj03382pcu.spreadtrum.com (10.0.74.65) by BJMBX01.spreadtrum.com (10.0.64.7) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Sun, 30 Oct 2022 11:42:56 +0800 From: "zhaoyang.huang" To: Andrew Morton , Catalin Marinas , Matthew Wilcox , Vlastimil Babka , Zhaoyang Huang , , , , Subject: [PATCHv3] mm: use stack_depot for recording kmemleak's backtrace Date: Sun, 30 Oct 2022 11:42:34 +0800 Message-ID: <1667101354-4669-1-git-send-email-zhaoyang.huang@unisoc.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [10.0.74.65] X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 29U3guO2084239 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Zhaoyang Huang Using stack_depot to record kmemleak's backtrace which has been implemented on slub for reducing redundant information. Signed-off-by: Zhaoyang Huang Acked-by: Catalin Marinas Cc: ke.wang Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Cc: Zhaoyang Huang Signed-off-by: Andrew Morton --- 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 #include #include +#include #include #include #include @@ -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_objec= t *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 =3D jiffies_to_msecs(jiffies - object->jiffies); =20 + nr_entries =3D 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"); =20 - for (i =3D 0; i < object->trace_len; i++) { - void *ptr =3D (void *)object->trace[i]; + for (i =3D 0; i < nr_entries; i++) { + void *ptr =3D (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 =3D %d\n", object->min_count); pr_notice(" count =3D %d\n", object->count); pr_notice(" flags =3D 0x%x\n", object->flags); pr_notice(" checksum =3D %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); } =20 /* @@ -591,12 +595,18 @@ static struct kmemleak_object *find_and_remove_object= (unsigned long ptr, int ali return object; } =20 -/* - * 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 =3D stack_trace_save(entries, ARRAY_SIZE(entries), 3); + trace_handle =3D stack_depot_save(entries, nr_entries, GFP_NOWAIT); + + return trace_handle; } =20 /* @@ -654,7 +664,7 @@ static struct kmemleak_object *__create_object(unsigned= long ptr, size_t size, } =20 /* kernel backtrace */ - object->trace_len =3D __save_stack_trace(object->trace); + object->trace_handle =3D set_track_prepare(); =20 raw_spin_lock_irqsave(&kmemleak_lock, flags); =20 @@ -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) } =20 raw_spin_lock_irqsave(&object->lock, flags); - object->trace_len =3D __save_stack_trace(object->trace); + object->trace_handle =3D set_track_prepare(); raw_spin_unlock_irqrestore(&object->lock, flags); =20 put_object(object); @@ -2064,6 +2073,7 @@ void __init kmemleak_init(void) if (kmemleak_error) return; =20 + stack_depot_init(); jiffies_min_age =3D msecs_to_jiffies(MSECS_MIN_AGE); jiffies_scan_wait =3D msecs_to_jiffies(SECS_SCAN_WAIT * 1000); =20 --=20 1.9.1