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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 5C78FC43331 for ; Mon, 4 Jan 2021 16:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4203D22522 for ; Mon, 4 Jan 2021 16:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729136AbhADQD2 (ORCPT ); Mon, 4 Jan 2021 11:03:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:40388 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729082AbhADQDR (ORCPT ); Mon, 4 Jan 2021 11:03:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CB59F22473; Mon, 4 Jan 2021 16:03:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609776182; bh=85umLspZZLssTIHeORxeLKC/V3HMsM1Z+tGZq32MKVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XecT9/OyrQg7dQ30KPRpCCLN94JUdq2igXhkbeK4s92aFYV8vbgYBTXwAcLK2RDz1 SPDZkCSH3O+3QCrkO/3IT1Nn9G528BftoJbfosD/TzX40ekTk3mRwKvrTjkA9QInPQ oKrjv1t+99cDUdy6tgwVrCcyN4EBYagoDzF8RUu0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiko Carstens , Sasha Levin Subject: [PATCH 5.10 58/63] s390: always clear kernel stack backchain before calling functions Date: Mon, 4 Jan 2021 16:57:51 +0100 Message-Id: <20210104155711.617987277@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210104155708.800470590@linuxfoundation.org> References: <20210104155708.800470590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Heiko Carstens [ Upstream commit 9365965db0c7ca7fc81eee27c21d8522d7102c32 ] Clear the kernel stack backchain before potentially calling the lockdep trace_hardirqs_off/on functions. Without this walking the kernel backchain, e.g. during a panic, might stop too early. Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/kernel/entry.S | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 6343dca0dbeb6..71203324ff42b 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -406,6 +406,7 @@ ENTRY(system_call) mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC stg %r14,__PT_FLAGS(%r11) + xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) ENABLE_INTS .Lsysc_do_svc: # clear user controlled register to prevent speculative use @@ -422,7 +423,6 @@ ENTRY(system_call) jnl .Lsysc_nr_ok slag %r8,%r1,3 .Lsysc_nr_ok: - xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) stg %r2,__PT_ORIG_GPR2(%r11) stg %r7,STACK_FRAME_OVERHEAD(%r15) lg %r9,0(%r8,%r10) # get system call add. @@ -712,8 +712,8 @@ ENTRY(pgm_check_handler) mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID -6: RESTORE_SM_CLEAR_PER - xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) +6: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) + RESTORE_SM_CLEAR_PER larl %r1,pgm_check_table llgh %r10,__PT_INT_CODE+2(%r11) nill %r10,0x007f @@ -734,8 +734,8 @@ ENTRY(pgm_check_handler) # PER event in supervisor state, must be kprobes # .Lpgm_kprobe: - RESTORE_SM_CLEAR_PER xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) + RESTORE_SM_CLEAR_PER lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_per_trap j .Lpgm_return @@ -777,10 +777,10 @@ ENTRY(io_int_handler) stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) + xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ jo .Lio_restore TRACE_IRQS_OFF - xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) .Lio_loop: lgr %r2,%r11 # pass pointer to pt_regs lghi %r3,IO_INTERRUPT @@ -980,10 +980,10 @@ ENTRY(ext_int_handler) mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS mvc __PT_INT_PARM_LONG(8,%r11),0(%r1) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) + xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ jo .Lio_restore TRACE_IRQS_OFF - xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs lghi %r3,EXT_INTERRUPT brasl %r14,do_IRQ -- 2.27.0