From nobody Mon Sep 15 00:22:47 2025 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 84F51C3DA78 for ; Tue, 17 Jan 2023 08:12:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235928AbjAQIMh (ORCPT ); Tue, 17 Jan 2023 03:12:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235942AbjAQIMb (ORCPT ); Tue, 17 Jan 2023 03:12:31 -0500 Received: from SHSQR01.spreadtrum.com (unknown [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B26BF22015 for ; Tue, 17 Jan 2023 00:12:26 -0800 (PST) Received: from SHSend.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by SHSQR01.spreadtrum.com with ESMTP id 30H8C8xe076583; Tue, 17 Jan 2023 16:12:08 +0800 (+08) (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; Tue, 17 Jan 2023 16:12:06 +0800 From: "zhaoyang.huang" To: Andrew Morton , Catalin Marinas , Vlastimil Babka , "Nathan Chancellor" , Peter Zijlstra , Zhaoyang Huang , , , , Mirsad Todorovac Subject: [PATCHv2] mm: use stack_depot_early_init for kmemleak Date: Tue, 17 Jan 2023 16:11:52 +0800 Message-ID: <1673943112-8620-1-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: SHCAS01.spreadtrum.com (10.0.1.201) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 30H8C8xe076583 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 Mirsad report bellow error which caused by stack_depot_init failed in kvcal= loc. Solve this by having stackdepot use stack_depot_early_init. Extra Kconfig a= lso done by moving kmemleak stuff to mm/Kconfig.debug. On 1/4/23 17:08, Mirsad Goran Todorovac wrote: I hate to bring bad news again, but there seems to be a problem with the ou= tput of /sys/kernel/debug/kmemleak: [root@pc-mtodorov ~]# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff951c118568b0 (size 16): comm "kworker/u12:2", pid 56, jiffies 4294893952 (age 4356.548s) hex dump (first 16 bytes): 6d 65 6d 73 74 69 63 6b 30 00 00 00 00 00 00 00 memstick0....... backtrace: [root@pc-mtodorov ~]# Apparently, backtrace of called functions on the stack is no longer prin= ted with the list of memory leaks. This appeared on Lenovo desktop 10TX000VCR, with AlmaLinux 8.7 and BIOS ve= rsion M22KT49A (11/10/2022) and 6.2-rc1 and 6.2-rc2 builds. This worked on 6.1 with the same CONFIG_KMEMLEAK=3Dy and MGLRU enabled on = a vanilla mainstream kernel from Mr. Torvalds' tree. I don't know if this is deliberate feature for so= me reason or a bug. Please find attached the config, lshw and kmemleak output. reported-by: Mirsad Todorovac suggested-by: Vlastimil Babka Signed-off-by: Zhaoyang Huang --- v2: use stack_depot_want_early_init instead of CONFIG_STACKDEPOT_ALWAYS_INIT --- --- lib/Kconfig.debug | 70 ---------------------------------------------------= ---- mm/Kconfig.debug | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++= ++++ mm/kmemleak.c | 4 +++- 3 files changed, 73 insertions(+), 71 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 401ad4b..62884ac 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -716,76 +716,6 @@ config SHRINKER_DEBUG visibility into the kernel memory shrinkers subsystem. Disable it to avoid an extra memory footprint. =20 -config HAVE_DEBUG_KMEMLEAK - bool - -config DEBUG_KMEMLEAK - bool "Kernel memory leak detector" - depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK - select DEBUG_FS - 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 - similar to the Boehm's conservative garbage collector, the - difference being that the orphan objects are not freed but - only shown in /sys/kernel/debug/kmemleak. Enabling this - feature will introduce an overhead to memory - allocations. See Documentation/dev-tools/kmemleak.rst for more - details. - - Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances - of finding leaks due to the slab objects poisoning. - - In order to access the kmemleak file, debugfs needs to be - mounted (usually at /sys/kernel/debug). - -config DEBUG_KMEMLEAK_MEM_POOL_SIZE - int "Kmemleak memory pool size" - depends on DEBUG_KMEMLEAK - range 200 1000000 - default 16000 - help - Kmemleak must track all the memory allocations to avoid - reporting false positives. Since memory may be allocated or - freed before kmemleak is fully initialised, use a static pool - of metadata objects to track such callbacks. After kmemleak is - fully initialised, this memory pool acts as an emergency one - if slab allocations fail. - -config DEBUG_KMEMLEAK_TEST - tristate "Simple test for the kernel memory leak detector" - depends on DEBUG_KMEMLEAK && m - help - This option enables a module that explicitly leaks memory. - - If unsure, say N. - -config DEBUG_KMEMLEAK_DEFAULT_OFF - bool "Default kmemleak to off" - depends on DEBUG_KMEMLEAK - help - Say Y here to disable kmemleak by default. It can then be enabled - on the command line via kmemleak=3Don. - -config DEBUG_KMEMLEAK_AUTO_SCAN - bool "Enable kmemleak auto scan thread on boot up" - default y - depends on DEBUG_KMEMLEAK - help - Depending on the cpu, kmemleak scan may be cpu intensive and can - stall user tasks at times. This option enables/disables automatic - kmemleak scan at boot up. - - Say N here to disable kmemleak auto scan thread to stop automatic - scanning. Disabling this option disables automatic reporting of - memory leaks. - - If unsure, say Y. - config DEBUG_STACK_USAGE bool "Stack utilization instrumentation" depends on DEBUG_KERNEL && !IA64 diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index ce8dded..d1893ac 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -207,3 +207,73 @@ config PTDUMP_DEBUGFS kernel. =20 If in doubt, say N. + +config HAVE_DEBUG_KMEMLEAK + bool + +config DEBUG_KMEMLEAK + bool "Kernel memory leak detector" + depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK + select DEBUG_FS + 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 + similar to the Boehm's conservative garbage collector, the + difference being that the orphan objects are not freed but + only shown in /sys/kernel/debug/kmemleak. Enabling this + feature will introduce an overhead to memory + allocations. See Documentation/dev-tools/kmemleak.rst for more + details. + + Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances + of finding leaks due to the slab objects poisoning. + + In order to access the kmemleak file, debugfs needs to be + mounted (usually at /sys/kernel/debug). + +config DEBUG_KMEMLEAK_MEM_POOL_SIZE + int "Kmemleak memory pool size" + depends on DEBUG_KMEMLEAK + range 200 1000000 + default 16000 + help + Kmemleak must track all the memory allocations to avoid + reporting false positives. Since memory may be allocated or + freed before kmemleak is fully initialised, use a static pool + of metadata objects to track such callbacks. After kmemleak is + fully initialised, this memory pool acts as an emergency one + if slab allocations fail. + +config DEBUG_KMEMLEAK_TEST + tristate "Simple test for the kernel memory leak detector" + depends on DEBUG_KMEMLEAK && m + help + This option enables a module that explicitly leaks memory. + + If unsure, say N. + +config DEBUG_KMEMLEAK_DEFAULT_OFF + bool "Default kmemleak to off" + depends on DEBUG_KMEMLEAK + help + Say Y here to disable kmemleak by default. It can then be enabled + on the command line via kmemleak=3Don. + +config DEBUG_KMEMLEAK_AUTO_SCAN + bool "Enable kmemleak auto scan thread on boot up" + default y + depends on DEBUG_KMEMLEAK + help + Depending on the cpu, kmemleak scan may be cpu intensive and can + stall user tasks at times. This option enables/disables automatic + kmemleak scan at boot up. + + Say N here to disable kmemleak auto scan thread to stop automatic + scanning. Disabling this option disables automatic reporting of + memory leaks. + + If unsure, say Y. diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 762b91f..ddc1ddf 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -2070,8 +2070,10 @@ static int __init kmemleak_boot_config(char *str) return -EINVAL; if (strcmp(str, "off") =3D=3D 0) kmemleak_disable(); - else if (strcmp(str, "on") =3D=3D 0) + else if (strcmp(str, "on") =3D=3D 0) { kmemleak_skip_disable =3D 1; + stack_depot_want_early_init(); + } else return -EINVAL; return 0; --=20 1.9.1