From nobody Sun Feb 8 06:49:36 2026 Received: from h3cspam02-ex.h3c.com (smtp.h3c.com [60.191.123.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CBF911D685; Wed, 28 Feb 2024 05:11:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=60.191.123.50 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709097101; cv=none; b=PFtkOMsbPgteyz+s2FpJYzKs1bA+djeALYvYsFm9TDFQKNbEuUSXf65NHcCAlFjKj8O3HfH/3QMLvlQpHyqiZZn7qcuaZ5b16+5309/Oqh8CQHEd927U7n5PsW845/VnlYwB+Eo+9XB9ayX/21+gNgLW9mMNZS1GbB1w4sskqr4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709097101; c=relaxed/simple; bh=6zpMQGqstL9uPpFOv76N6PFMaID669Pd5/NbhzWUD/E=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=qBnv3BOcLFeP3JG7mf5PNUqxgdyU8+GQ3hugcSEjVSoH0Ijiet9NlgopLENY0JKQ6P2l9rQ5Cj60Wy/s+BWINYPacN7652Gy40qpb+PsINS9KB8tpsy2K3+I6JcUejSLh2YIaS0pMNOR8JD7F8BW48FwjlGDXOQkIMHaP++tgPc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=h3c.com; spf=pass smtp.mailfrom=h3c.com; arc=none smtp.client-ip=60.191.123.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=h3c.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=h3c.com Received: from h3cspam02-ex.h3c.com (localhost [127.0.0.2] (may be forged)) by h3cspam02-ex.h3c.com with ESMTP id 41S2vifp091258; Wed, 28 Feb 2024 10:57:44 +0800 (GMT-8) (envelope-from liu.yeC@h3c.com) Received: from mail.maildlp.com ([172.25.15.154]) by h3cspam02-ex.h3c.com with ESMTP id 41S2uMv7083766; Wed, 28 Feb 2024 10:56:22 +0800 (GMT-8) (envelope-from liu.yeC@h3c.com) Received: from DAG6EX02-IMDC.srv.huawei-3com.com (unknown [10.62.14.11]) by mail.maildlp.com (Postfix) with ESMTP id F15DC2004BB7; Wed, 28 Feb 2024 10:57:30 +0800 (CST) Received: from localhost.localdomain (10.114.186.34) by DAG6EX02-IMDC.srv.huawei-3com.com (10.62.14.11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1258.27; Wed, 28 Feb 2024 10:56:22 +0800 From: LiuYe To: , CC: , , , , , , Subject: [PATCH] kdb: Fix the deadlock issue in KDB debugging. Date: Wed, 28 Feb 2024 10:56:02 +0800 Message-ID: <20240228025602.3087748-1-liu.yeC@h3c.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: BJSMTP02-EX.srv.huawei-3com.com (10.63.20.133) To DAG6EX02-IMDC.srv.huawei-3com.com (10.62.14.11) X-DNSRBL: X-SPAM-SOURCE-CHECK: pass X-MAIL: h3cspam02-ex.h3c.com 41S2vifp091258 Content-Type: text/plain; charset="utf-8" master cpu : After executing the go command, a deadlock occurs. slave cpu: may be performing thread migration, acquiring the running queue lock of master CPU. Then it was interrupted by kdb NMI and entered the nmi_handler proc= ess. (nmi_handle-> kgdb_nmicallback-> kgdb_cpu_enter while(1){ touch wathcdog}.) example: BUG: spinlock lockup suspected on CPU#0, namex/10450 lock: 0xffff881ffe823980, .magic: dead4ead, .owner: namexx/21888, .owner_c= pu: 1 ffff881741d00000 ffff881741c01000 0000000000000000 0000000000000000 ffff881740f58e78 ffff881741cffdd0 ffffffff8147a7fc ffff881740f58f20 Call Trace: [] ? __schedule+0x16d/0xac0 [] ? schedule+0x3c/0x90 [] ? schedule_hrtimeout_range_clock+0x10a/0x120 [] ? mutex_unlock+0xe/0x10 [] ? ep_scan_ready_list+0x1db/0x1e0 [] ? schedule_hrtimeout_range+0x13/0x20 [] ? ep_poll+0x27a/0x3b0 [] ? wake_up_q+0x70/0x70 [] ? SyS_epoll_wait+0xb8/0xd0 [] ? entry_SYSCALL_64_fastpath+0x12/0x75 CPU: 0 PID: 10450 Comm: namex Tainted: G O 4.4.65 #1 Hardware name: Insyde Purley/Type2 - Board Product Name1, BIOS 05.21.51.00= 36 07/19/2019 0000000000000000 ffff881ffe813c10 ffffffff8124e883 ffff881741c01000 ffff881ffe823980 ffff881ffe813c38 ffffffff810a7f7f ffff881ffe823980 000000007d2b7cd0 0000000000000001 ffff881ffe813c68 ffffffff810a80e0 Call Trace: <#DB> [] dump_stack+0x85/0xc2 [] spin_dump+0x7f/0x100 [] do_raw_spin_lock+0xa0/0x150 [] _raw_spin_lock+0x15/0x20 [] try_to_wake_up+0x176/0x3d0 [] wake_up_process+0x15/0x20 [] insert_work+0x81/0xc0 [] __queue_work+0x135/0x390 [] queue_work_on+0x46/0x90 [] kgdboc_post_exp_handler+0x48/0x70 [] kgdb_cpu_enter+0x598/0x610 [] kgdb_handle_exception+0xf2/0x1f0 [] __kgdb_notify+0x71/0xd0 [] kgdb_notify+0x35/0x70 [] notifier_call_chain+0x4a/0x70 [] notify_die+0x3d/0x50 [] do_int3+0x89/0x120 [] int3+0x44/0x80 Signed-off-by: LiuYe --- drivers/tty/serial/kgdboc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c index 7ce7bb164..945318ef1 100644 --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -22,6 +22,9 @@ #include #include #include +#include + +#include "../kernel/sched/sched.h" #define MAX_CONFIG_LEN 40 @@ -399,7 +402,8 @@ static void kgdboc_post_exp_handler(void) dbg_restore_graphics =3D 0; con_debug_leave(); } - kgdboc_restore_input(); + if (!raw_spin_is_locked(&(cpu_rq(smp_processor_id())->lock))) + kgdboc_restore_input(); } static struct kgdb_io kgdboc_io_ops =3D { -- 2.25.1 ---------------------------------------------------------------------------= ---------------------------------------------------------- =EF=BF=BD=EF=BF=BD=EF=BF=BD=CA=BC=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=E4=B8= =BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=C2=BB=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=C5=B5=C4=B1=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=CF=A2=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD= =EF=BF=BD=EF=BF=BD=EF=BF=BD=DA=B7=EF=BF=BD=EF=BF=BD=CD=B8=EF=BF=BD=EF=BF=BD= =EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=D6=B7=EF=BF=BD=EF=BF=BD=EF=BF=BD=D0=B3= =EF=BF=BD =EF=BF=BD=C4=B8=EF=BF=BD=EF=BF=BD=CB=BB=EF=BF=BD=C8=BA=EF=BF=BD=E9=A1=A3=EF= =BF=BD=EF=BF=BD=D6=B9=EF=BF=BD=CE=BA=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=CE=BA=EF=BF=BD=EF=BF=BD= =EF=BF=BD=CA=BD=CA=B9=EF=BF=BD=C3=A3=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF= =BD=C8=AB=EF=BF=BD=EF=BF=BD=EF=BF=BD=F2=B2=BF=B7=D6=B5=EF=BF=BD=D0=B9=C2=B6= =EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=C6=A1=EF=BF=BD =EF=BF=BD=EF=BF=BD=C9=A2=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF= =BD=EF=BF=BD=CA=BC=EF=BF=BD=EF=BF=BD=D0=B5=EF=BF=BD=EF=BF=BD=EF=BF=BD=CF=A2= =EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=CB=B1=EF=BF=BD=EF=BF=BD=CA=BC=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF= =BD=EF=BF=BD=EF=BF=BD=E7=BB=B0=EF=BF=BD=EF=BF=BD=EF=BF=BD=CA=BC=EF=BF=BD=CD= =A8=D6=AA=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=CB=B2=EF=BF=BD=C9=BE= =EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD =EF=BF=BD=CA=BC=EF=BF=BD=EF=BF=BD=EF=BF=BD This e-mail and its attachments contain confidential information from New H= 3C, which is intended only for the person or entity whose address is listed above. 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