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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 25 Jul 2018 16:51:12 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w6PKpBG15112106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 25 Jul 2018 20:51:11 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C032DAC059; Wed, 25 Jul 2018 16:51:55 -0400 (EDT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F2E76AC05E; Wed, 25 Jul 2018 16:51:54 -0400 (EDT) Received: from localhost (unknown [9.85.190.157]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTPS; Wed, 25 Jul 2018 16:51:54 -0400 (EDT) Date: Wed, 25 Jul 2018 17:51:08 -0300 From: Murilo Opsfelder Araujo To: LEROY Christophe Cc: linuxppc-dev@lists.ozlabs.org, "Tobin C . Harding" , Sukadev Bhattiprolu , Simon Guo , Paul Mackerras , Nicholas Piggin , Michael Neuling , Michael Ellerman , "Eric W . Biederman" , Cyril Bur , Benjamin Herrenschmidt , Balbir Singh , Andrew Donnellan , "Alastair D'Silva" , linux-kernel@vger.kernel.org Subject: Re: [PATCH 7/7] powerpc/traps: Show instructions on exceptions References: <20180724192720.32417-1-muriloo@linux.ibm.com> <20180724192720.32417-8-muriloo@linux.ibm.com> <20180725180134.Horde.BdhyE2b-TXhoVB7W8bsBhg1@messagerie.si.c-s.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180725180134.Horde.BdhyE2b-TXhoVB7W8bsBhg1@messagerie.si.c-s.fr> User-Agent: Mutt/1.10.0 (2018-05-17) X-TM-AS-GCONF: 00 x-cbid: 18072520-0052-0000-0000-0000031371B8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009427; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01066079; UDB=6.00547685; IPR=6.00843939; MB=3.00022324; MTD=3.00000008; XFM=3.00000015; UTC=2018-07-25 20:51:16 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18072520-0053-0000-0000-00005D7D8D6C Message-Id: <20180725205108.GE23643@kermit-br-ibm-com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-25_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807250216 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Christophe. On Wed, Jul 25, 2018 at 06:01:34PM +0200, LEROY Christophe wrote: > Murilo Opsfelder Araujo a écrit : > > > Move show_instructions() declaration to arch/powerpc/include/asm/stacktrace.h > > and include asm/stracktrace.h in arch/powerpc/kernel/process.c, which > > contains > > the implementation. > > > > Modify show_instructions() not to call __kernel_text_address(), allowing > > userspace instruction dump. probe_kernel_address(), which returns -EFAULT if > > something goes wrong, is still being called. > > > > Call show_instructions() in arch/powerpc/kernel/traps.c to dump > > instructions at > > faulty location, useful to debugging. > > Shouldn't this part be in a second patch ? Makes sense. Perhaps I should split this patch in two: one to remove __kernel_text_address() check in show_instructions(), and another to call show_instructions() in show_signal_msg(). > Wouldn't it be better to also see regs in addition if we want to use this to > understand what happened ? > So you could call show_regs() instead of show_instructions() ? I see that show_regs() prints more information and calls show_instructions() at the end if in privileged state. I'm not sure about which situations we might want to call show_regs() - and display a bunch of information - or just dump instructions for some signals. Isn't calling show_regs() in this case considered overkill? Cheers Murilo