From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx07-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by sourceware.org (Postfix) with ESMTPS id 7C18A396E054 for ; Thu, 2 Jun 2022 14:18:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7C18A396E054 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 2528Q8Me013089; Thu, 2 Jun 2022 16:18:04 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3gespq1x8e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 02 Jun 2022 16:18:04 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 8A97210002A; Thu, 2 Jun 2022 16:18:03 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node2.st.com [10.75.129.70]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 22F4F22AFFA; Thu, 2 Jun 2022 16:18:03 +0200 (CEST) Received: from gnbcxd0114.gnb.st.com (10.75.127.50) by SHFDAG1NODE2.st.com (10.75.129.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.20; Thu, 2 Jun 2022 16:18:02 +0200 Date: Thu, 2 Jun 2022 16:18:01 +0200 From: Yvan Roux To: CC: Luis Machado , Torbjorn SVENSSON Subject: [PATCH] gdb/arm: Terminate unwinding when LR is 0xffffffff Message-ID: <20220602141801.GA23363@gnbcxd0114.gnb.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.9.4 (2018-02-28) X-Originating-IP: [10.75.127.50] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SHFDAG1NODE2.st.com (10.75.129.70) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-02_03,2022-06-02_01,2022-02-23_01 X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jun 2022 14:18:09 -0000 Hi, ARMv7-M Architecture Reference "A2.3.1 Arm core registers" states that LR is set to 0xffffffff on reset. ARMv8-M Architecture Reference "B3.3 Registers" states that LR is set to 0xffffffff on warm reset if Main Extension is implemented, otherwise the value is unknown. Signed-off-by: Torbjörn SVENSSON Signed-off-by: Yvan Roux --- gdb/arm-tdep.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 50ec41a66b1..5ec0e642cc7 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -3330,6 +3330,17 @@ arm_m_exception_cache (struct frame_info *this_frame) lr = get_frame_register_unsigned (this_frame, ARM_LR_REGNUM); sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); + /* ARMv7-M Architecture Reference "A2.3.1 Arm core registers" + states that LR is set to 0xffffffff on reset. ARMv8-M Architecture + Reference "B3.3 Registers" states that LR is set to 0xffffffff on warm + reset if Main Extension is implemented, otherwise the value is unknown. */ + if (lr == 0xffffffff) + { + /* Terminate any further stack unwinding by referring to self. */ + arm_cache_set_active_sp_value (cache, tdep, sp); + return cache; + } + fnc_return = ((lr & 0xfffffffe) == 0xfefffffe); if (tdep->have_sec_ext && fnc_return) { -- 2.17.1