From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752530AbeDLBem (ORCPT ); Wed, 11 Apr 2018 21:34:42 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:59824 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751858AbeDLBei (ORCPT ); Wed, 11 Apr 2018 21:34:38 -0400 Date: Thu, 12 Apr 2018 04:34:35 +0300 From: "Dmitry V. Levin" To: "Eric W. Biederman" Cc: Linus Torvalds , linuxppc-dev@lists.ozlabs.org, linux-sparc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid Message-ID: <20180412013435.GA21219@altlinux.org> Mail-Followup-To: "Eric W. Biederman" , Linus Torvalds , linuxppc-dev@lists.ozlabs.org, linux-sparc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20180409152253.GD10489@altlinux.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="J2SCkAp4GZ/dPZZf" Content-Disposition: inline In-Reply-To: <20180409152253.GD10489@altlinux.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --J2SCkAp4GZ/dPZZf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Mon, Apr 09, 2018 at 06:22:53PM +0300, Dmitry V. Levin wrote: > There seems to be a regression in v4.16 on ppc compat very similar > to sparc compat regression reported earlier at > https://marc.info/?l=3Dlinux-sparc&m=3D151501500704383 . >=20 > The symptoms are exactly the same: the same signal_receive test from > the strace test suite fails with the same diagnostics: > https://build.opensuse.org/public/build/home:ldv_alt/openSUSE_Factory_Pow= erPC/ppc/strace/_log The log is big, just look for "KERNEL BUG". > Unfortunately, I do not have any means to investigate further, > so just passing this information on to those who care. OK, the faulty commit is v4.16-rc1~159^2~39 ("signal/powerpc: Document conflicts with SI_USER and SIGFPE and SIGTRAP"). One might think that a commit called "Document conflicts" shouldn't introduce an ABI regression, but this one definitely does by defining FPE_FIXME and TRAP_FIXME in arch/powerpc/include/uapi/asm/siginfo.h that affect siginfo_layout(). A similar commit v4.16-rc1~159^2~37 ("signal/arm: Document conflicts with SI_USER and SIGFPE") must have introduced a similar ABI regression to compat arm. An earlier commit v4.14-rc1~60^2^2~5 ("signal/sparc: Document a conflict with SI_USER with SIGFPE") introduced a similar ABI regression to compat sparc. There is a clear pattern of sneaking in ABI changes using innocently looking commit messages. --=20 ldv --J2SCkAp4GZ/dPZZf Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJazrerAAoJEAVFT+BVnCUIChMQAJxouuxIeyN9pi7FZQztb3Fr hU39sGuyIpVMJ50K4dJq/3Yo+t+q+8AUWSg8sHQEqe4JzRR26dhVr8cYr6XsBftY x6+qiWhvBGoTZbpJbBmZFrkaCWEjgTws8W9YBUzoYxLLNLCWAXrcf6UGL9kQmZqY I7GdvUlsO6B9xFFaQOkgpqNizI7N5mI0dV+SoMdgMs0psoq0C+1vDmG6lknDzdi1 mqLffdhMisnO+mdL+ixp3keV0daIjN7liDclCX0pxBzedNm4ilc3FwSPvxpjhwsB di6WJ9CiBjHRpl65jz9E8DVz6+FFdPf1pKCD650vPTmA7XnFOTeALaYTPUUsPovW vXTY/3SLDgmD++vWd5PwJrkxo1I3rk0CifGcoQn4UTHXOzGHZunkETpS/PSoXFc4 AhSQVEjlMARxedt0wmTE3m13tUwttiRz4kT9vJrnd9nchYg6Bc/SwhrSxjJYyWUJ DwsBFowrdKR9Bt67QZKaAU17hq9zPBZ3IxpnZ1ZbvTk62T8pmZQheve1YO69w0dg gB5gLlmwKOMJ/ZS8H/fD4ro257j/gMEhfVRroCwPzKSQ+fm7h+XEHSFK7yl6DQ28 tGIOuyqGADAX7A/CS8BkuAe0WezklG5JphMiEaU4ClLxLb0Nz5avGYvY19UgtE7U 7E7ani2qtbR2nf97TPi3 =Xlro -----END PGP SIGNATURE----- --J2SCkAp4GZ/dPZZf--