From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C306DC433F5 for ; Sun, 19 Sep 2021 18:36:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7BF860F51 for ; Sun, 19 Sep 2021 18:36:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230406AbhISShx (ORCPT ); Sun, 19 Sep 2021 14:37:53 -0400 Received: from mail.ispras.ru ([83.149.199.84]:39514 "EHLO mail.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbhISShw (ORCPT ); Sun, 19 Sep 2021 14:37:52 -0400 Received: from [192.168.1.41] (unknown [109.252.87.67]) by mail.ispras.ru (Postfix) with ESMTPSA id AB7D740D4004; Sun, 19 Sep 2021 18:36:20 +0000 (UTC) Subject: Re: [PATCH 5.10 033/306] cpufreq: schedutil: Use kobject release() method to free sugov_tunables To: Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Kevin Hao , Viresh Kumar References: <20210916155753.903069397@linuxfoundation.org> <20210916155755.075805845@linuxfoundation.org> From: Alexey Khoroshilov Autocrypt: addr=khoroshilov@ispras.ru; prefer-encrypt=mutual; keydata= xsFNBFtq9eIBEACxmOIPDht+aZvO9DGi4TwnZ1WTDnyDVz3Nnh0rlQCK8IssaT6wE5a95VWo iwOWalcL9bJMHQvw60JwZKFjt9oH2bov3xzx/JRCISQB4a4U1J/scWvPtabbB3t+VAodF5KZ vZ2gu/Q/Wa5JZ9aBH0IvNpBAAThFg1rBXKh7wNqrhsQlMLg+zTSK6ZctddNl6RyaJvAmbaTS sSeyUKXiabxHn3BR9jclXfmPLfWuayinBvW4J3vS+bOhbLxeu3MO0dUqeX/Nl8EAhvzo0I2d A0vRu/Ze1wU3EQYT6M8z3i1b3pdLjr/i+MI8Rgijs+TFRAhxRw/+0vHGTg6Pn02t0XkycxQR mhH3v0kVTvMyM7YSI7yXvd0QPxb1RX9AGmvbJu7eylzcq9Jla+/T3pOuWsJkbvbvuFKKmmYY WnAOR7vu/VNVfiy4rM0bfO14cIuEG+yvogcPuMmQGYu6ZwS9IdgZIOAkO57M/6wR0jIyfxrG FV3ietPtVcqeDVrcShKyziRLJ+Xcsg9BLdnImAqVQomYr27pyNMRL5ILuT7uOuAQPDKBksK+ l2Fws0d5iUifqnXSPuYxqgS4f8SQLS7ECxvCGVVbkEEng9vkkmyrF6wM86BZ9apPGDFbopiK 7GRxQtSGszVv83abaVb8aDsAudJIp7lLaIuXLZAe1r+ycYpEtQARAQABzSpBbGV4ZXkgS2hv cm9zaGlsb3YgPGtob3Jvc2hpbG92QGlzcHJhcy5ydT7CwX0EEwEIACcFAltq9eICGwMFCRLM AwAFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ2B/JSzCwrEWLaA/+NFZfyhU0vJzFtYsk yaqx8nWZLrAoUK7VcobH0lJH6lfGbarO5JpENaIiTP12YZ4xO+j3GGJtLy2gvnpypGnxmiAl RqPt7WeAIj6oqPrUs2QF7i4SOiPtku/NrysI1zHzlA8yqUduBtam5rdQeLRNCJiEED1fU8sp +DgJBN/OHEDyAag2hu1KFKWuPfQ+QGpXYZb+1NW/hKwvvwCNVyypELAfFnkketFXjIMwHnL8 ZPqJZlkvkpxuRXOaXPL9NFhZnC/WS+NJ81L3pr+w6eo3xTPYZvRW8glvqlEDgHqr3uMGIaes nwfRXLHp+TC1ht6efCXzdPyMZ1E7HXQN9foKisI1V5iQFhN+CT3dbsguQI4e10F5ql0TZUJY SMzvY0eObs6TWRdD/Ha7Y5rLmZ54R9sxumpZNcJzktfgm9f0XfeqVEJUn/40MRDD+l2W12Db Jkko+sbtAEw+f+/j3uz8xOE+Uv4kwFC5a6JKgdX88oigHnpAs3FvffP594Loi3ibFrQUW5wH bXh5Ni+l1GKEQ0PHMk+KQQT9L2r9s7C0Nh8XzwdpOshZWsrNSZqcG+01wrmUhyX2uSaoZ07I /+KZURlMSqI71X6lkMWlB3SyThvYhHgnR0EGGTerwM1MaVjHN+Z6lPmsKNxG8lzCeWeZ6peA c5oUHV4WQ8Ux9BM8saLOwU0EW2r14gEQAMz+5u+X7j1/dT4WLVRQaE1Shnd2dKBn2E7fgo/N 4JIY6wHD/DJoWYQpCJjjvBYSonvQsHicvDW8lPh2EXgZ9Fi8AHKT2mVPitVy+uhfWa/0FtsC e3hPfrjTcN7BUcXlIjmptxIoDbvQrNfIWUGdWiyDj4EDfABW/kagXqaBwF2HdcDaNDGggD1c DglA0APjezIyTGnGMKsi5QSSlOLm8OZEJMj5t+JL6QXrruijNb5Asmz5mpRQrak7DpGOskjK fClm/0oy2zDvWuoXJa+dm3YFr43V+c5EIMA4LpGk63Eg+5NltQ/gj0ycgD5o6reCbjLz4R9D JzBezK/KOQuNG5qKUTMbOHWaApZnZ6BDdOVflkV1V+LMo5GvIzkATNLm/7Jj6DmYmXbKoSAY BKZiJWqzNsL1AJtmJA1y5zbWX/W4CpNs8qYMYG8eTNOqunzopEhX7T0cOswcTGArZYygiwDW BuIS83QRc7udMlQg79qyMA5WqS9g9g/iodlssR9weIVoZSjfjhm5NJ3FmaKnb56h6DSvFgsH xCa4s1DGnZGSAtedj8E3ACOsEfu4J/WqXEmvMYNBdGos2YAc+g0hjuOB10BSD98d38xP1vPc qNrztIF+TODAl1dNwU4rCSdGQymsrMVFuXnHMH4G+dHvMAwWauzDbnILHAGFyJtfxVefABEB AAHCwWUEGAEIAA8FAltq9eICGwwFCRLMAwAACgkQ2B/JSzCwrEU3Rg//eFWHXqTQ5CKw4KrX kTFxdXnYKJ5zZB0EzqU6m/FAV7snmygFLbOXYlcMW2Fh306ivj9NKJrlOaPbUzzyDf8dtDAg nSbH156oNJ9NHkz0mrxFMpJA2E5AUemOFx57PUYt93pR2B7bF2zGua4gMC+vorDQZjX9kvrL Kbenh3boFOe1tUaiRRvEltVFLOg+b+CMkKVbLIQe/HkyKJH5MFiHAF7QxnPHaxyO7QbWaUmF 6BHVujxAGvNgkrYJb6dpiNNZSFNRodaSToU5oM+z1dCrNNtN3u4R7AYr6DDIDxoSzR4k0ZaG uSeqh4xxQCD7vLT3JdZDyhYUJgy9mvSXdkXGdBIhVmeLch2gaWNf5UOutVJwdPbIaUDRjVoV Iw6qjKq+mnK3ttuxW5Aeg9Y1OuKEvCVu+U/iEEJxx1JRmVAYq848YqtVPY9DkZdBT4E9dHqO n8lr+XPVyMN6SBXkaR5tB6zSkSDrIw+9uv1LN7QIri43fLqhM950ltlveROEdLL1bI30lYO5 J07KmxgOjrvY8X9WOC3O0k/nFpBbbsM4zUrmF6F5wIYO99xafQOlfpUnVtbo3GnBR2LIcPYj SyY3dW28JXo2cftxIOr1edJ+fhcRqYRrPzJrQBZcE2GZjRO8tz6IOMAsc+WMtVfj5grgVHCu kK2E04Fb+Zk1eJvHYRc= Message-ID: <175d4888-1147-9a2f-32d6-7c90c2628af5@ispras.ru> Date: Sun, 19 Sep 2021 21:36:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: ru-RU Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16.09.2021 20:20, Greg Kroah-Hartman wrote: > On Thu, Sep 16, 2021 at 06:12:44PM +0200, Rafael J. Wysocki wrote: >> On 9/16/2021 5:56 PM, Greg Kroah-Hartman wrote: >>> From: Kevin Hao >>> >>> commit e5c6b312ce3cc97e90ea159446e6bfa06645364d upstream. >>> >>> The struct sugov_tunables is protected by the kobject, so we can't free >>> it directly. Otherwise we would get a call trace like this: >>> ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30 >>> WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 >>> Modules linked in: >>> CPU: 3 PID: 720 Comm: a.sh Tainted: G W 5.14.0-rc1-next-20210715-yocto-standard+ #507 >>> Hardware name: Marvell OcteonTX CN96XX board (DT) >>> pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) >>> pc : debug_print_object+0xb8/0x100 >>> lr : debug_print_object+0xb8/0x100 >>> sp : ffff80001ecaf910 >>> x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80 >>> x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000 >>> x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20 >>> x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010 >>> x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365 >>> x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69 >>> x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0 >>> x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001 >>> x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000 >>> x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000 >>> Call trace: >>> debug_print_object+0xb8/0x100 >>> __debug_check_no_obj_freed+0x1c0/0x230 >>> debug_check_no_obj_freed+0x20/0x88 >>> slab_free_freelist_hook+0x154/0x1c8 >>> kfree+0x114/0x5d0 >>> sugov_exit+0xbc/0xc0 >>> cpufreq_exit_governor+0x44/0x90 >>> cpufreq_set_policy+0x268/0x4a8 >>> store_scaling_governor+0xe0/0x128 >>> store+0xc0/0xf0 >>> sysfs_kf_write+0x54/0x80 >>> kernfs_fop_write_iter+0x128/0x1c0 >>> new_sync_write+0xf0/0x190 >>> vfs_write+0x2d4/0x478 >>> ksys_write+0x74/0x100 >>> __arm64_sys_write+0x24/0x30 >>> invoke_syscall.constprop.0+0x54/0xe0 >>> do_el0_svc+0x64/0x158 >>> el0_svc+0x2c/0xb0 >>> el0t_64_sync_handler+0xb0/0xb8 >>> el0t_64_sync+0x198/0x19c >>> irq event stamp: 5518 >>> hardirqs last enabled at (5517): [] console_unlock+0x554/0x6c8 >>> hardirqs last disabled at (5518): [] el1_dbg+0x28/0xa0 >>> softirqs last enabled at (5504): [] __do_softirq+0x4d0/0x6c0 >>> softirqs last disabled at (5483): [] irq_exit+0x1b0/0x1b8 >>> >>> So split the original sugov_tunables_free() into two functions, >>> sugov_clear_global_tunables() is just used to clear the global_tunables >>> and the new sugov_tunables_free() is used as kobj_type::release to >>> release the sugov_tunables safely. >>> >>> Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data") >>> Cc: 4.7+ # 4.7+ >>> Signed-off-by: Kevin Hao >>> Acked-by: Viresh Kumar >>> Signed-off-by: Rafael J. Wysocki >>> Signed-off-by: Greg Kroah-Hartman >>> --- >>> kernel/sched/cpufreq_schedutil.c | 16 +++++++++++----- >>> 1 file changed, 11 insertions(+), 5 deletions(-) >>> >>> --- a/kernel/sched/cpufreq_schedutil.c >>> +++ b/kernel/sched/cpufreq_schedutil.c >>> @@ -610,9 +610,17 @@ static struct attribute *sugov_attrs[] = >>> }; >>> ATTRIBUTE_GROUPS(sugov); >>> +static void sugov_tunables_free(struct kobject *kobj) >>> +{ >>> + struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj); >>> + >>> + kfree(to_sugov_tunables(attr_set)); >>> +} >>> + >>> static struct kobj_type sugov_tunables_ktype = { >>> .default_groups = sugov_groups, >>> .sysfs_ops = &governor_sysfs_ops, >>> + .release = &sugov_tunables_free, >>> }; >>> /********************** cpufreq governor interface *********************/ >>> @@ -712,12 +720,10 @@ static struct sugov_tunables *sugov_tuna >>> return tunables; >>> } >>> -static void sugov_tunables_free(struct sugov_tunables *tunables) >>> +static void sugov_clear_global_tunables(void) >>> { >>> if (!have_governor_per_policy()) >>> global_tunables = NULL; >>> - >>> - kfree(tunables); >>> } >>> static int sugov_init(struct cpufreq_policy *policy) >>> @@ -780,7 +786,7 @@ out: >>> fail: >>> kobject_put(&tunables->attr_set.kobj); >>> policy->governor_data = NULL; >>> - sugov_tunables_free(tunables); >>> + sugov_clear_global_tunables(); >>> stop_kthread: >>> sugov_kthread_stop(sg_policy); >>> @@ -807,7 +813,7 @@ static void sugov_exit(struct cpufreq_po >>> count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); >>> policy->governor_data = NULL; >>> if (!count) >>> - sugov_tunables_free(tunables); >>> + sugov_clear_global_tunables(); >>> mutex_unlock(&global_tunables_lock); >>> >>> >> Please defer this one. >> >> It uncovers a bug in cpufreq that needs to be fixed separately. > > Now dropped from all queues, thanks! > > greg k-h > Hi Greg, I am trying to get familiar with stable release process, because we would like to start testing stable release candidates. But I cannot get all the nuances how to get automatically information regarding rc code ready to be tested. Also I wonder how we could automatically detect situations when stable release is expected to became diverged from the rc, e.g. like [PATCH 5.10 033/306] cpufreq: schedutil: Use kobject release() method to free sugov_tunables was dropped from 5.10.67 without announcing the 5.10.67-rc2? Any suggestions are appreciated. Best regards, Alexey Khoroshilov, Linux Verification Center, ISPRAS