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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 10 Jun 2019 16:27:16 +0100 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5AFREZv35914148 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 10 Jun 2019 15:27:14 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8F287112061; Mon, 10 Jun 2019 15:27:14 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 834D3112062; Mon, 10 Jun 2019 15:27:07 +0000 (GMT) Received: from LeoBras (unknown [9.80.212.30]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 10 Jun 2019 15:27:07 +0000 (GMT) Subject: Re: [RFC V3] mm: Generalize and rename notify_page_fault() as kprobe_page_fault() From: Leonardo Bras To: Anshuman Khandual , Christophe Leroy , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Mark Rutland , Michal Hocko , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Dave Hansen , Heiko Carstens , Paul Mackerras , Matthew Wilcox , sparclinux@vger.kernel.org, linux-s390@vger.kernel.org, Yoshinori Sato , x86@kernel.org, Russell King , Will Deacon , Ingo Molnar , Fenghua Yu , Stephen Rothwell , Andrey Konovalov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Tony Luck , Martin Schwidefsky , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Date: Mon, 10 Jun 2019 12:27:02 -0300 In-Reply-To: <97e9c9b3-89c8-d378-4730-841a900e6800@arm.com> References: <1559903655-5609-1-git-send-email-anshuman.khandual@arm.com> <97e9c9b3-89c8-d378-4730-841a900e6800@arm.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-5Zy/vH+sEK4zQeyqr1da" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19061015-0060-0000-0000-0000034E9532 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011243; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01216003; UDB=6.00639329; IPR=6.00997102; MB=3.00027253; MTD=3.00000008; XFM=3.00000015; UTC=2019-06-10 15:27:23 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19061015-0061-0000-0000-000049B7F47B Message-Id: <8dd6168592437378ff4a7c204e0f2962d002b44f.camel@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-10_07:,, 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=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=628 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906100106 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --=-5Zy/vH+sEK4zQeyqr1da Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2019-06-10 at 08:09 +0530, Anshuman Khandual wrote: > > > + /* > > > + * To be potentially processing a kprobe fault and to be allowed > > > + * to call kprobe_running(), we have to be non-preemptible. > > > + */ > > > + if (kprobes_built_in() && !preemptible() && !user_mode(regs)) { > > > + if (kprobe_running() && kprobe_fault_handler(regs, trap)) > >=20 > > don't need an 'if A if B', can do 'if A && B' >=20 > Which will make it a very lengthy condition check. Well, is there any problem line-breaking the if condition? if (A && B && C && D && E ) Also, if it's used only to decide the return value, maybe would be fine to do somethink like that: return (A && B && C && D && E );=20 Regards, --=-5Zy/vH+sEK4zQeyqr1da Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEMdeUgIzgjf6YmUyOlQYWtz9SttQFAlz+dsYACgkQlQYWtz9S ttTfRQ/7BnCF2Sm8vpCKt6ji0Aq2vGhwsM6ISA+Vx72iI70yBg1jdV88yhko7lp4 xOwZejel20zp4V3f2xXCpyVnjbg0RNSBBHjkSsWJTHPQd+dVYqoLkR98Q8WrV1Q+ o0LxhoGGEpJwQanH1WL/P1t1crvBt4Htbg9wXfdbJGiFKDvsocC/fBuNkbijcGl2 JvLF8LFak6qojcDxLu4xvBIIrEuL60RklTTRwlZyKi3z4hfZUPLuUkpv4BYexDKU mbJMxgJ/IgrCWmteuPXuVZHgK80UpvJUM6jacPRWdiIDQ0zG2NbJRh8o7WS4ZtaA mShCl/Y72OZ9INtiP9ZTHItZyksARvwzFalnkyNkpdigr0FgLYy9tjYlD6ex6Z6W qWrJSWPsUGDvcE5iy0tfRp/Vq03w1YNbofrg0eIo995y3VW8BM4rR72OrFMWeSuM x7/4o4EvjYwVK9GTJWECK6wNH/+V3DUgMOJk9SFCde5Qdkg2i9Xpl9prxij8YMFc AUDqw6hStj1Sb/XfJXIwpHflJsfTK2pozWISJInBkyxFnEIpNpQAHUPn1I1l26LQ pDL47J1Wn/zM1EtAIgDOEATxWPyRqJN4nFniwAVhMslHB44MAS+XY3KPAr24zSM2 +t+VW/uhJw9igsLPPpyhzQa34M6O+tvw/pHV/IrJCm2vzNBdu9E= =oA4R -----END PGP SIGNATURE----- --=-5Zy/vH+sEK4zQeyqr1da--