https://github.com/torvalds/linux
Revision 595d153dd1022392083ac93a1550382cbee127e0 authored by Michael Ellerman on 26 May 2020, 06:18:08 UTC, committed by Michael Ellerman on 26 May 2020, 07:32:37 UTC
Commit 702f09805222 ("powerpc/64s/exception: Remove lite interrupt
return") changed the interrupt return path to not restore non-volatile
registers by default, and explicitly restore them in paths where it is
required.

But it missed that the facility unavailable exception can sometimes
modify user registers, ie. when it does emulation of move from DSCR.

This is seen as a failure of the dscr_sysfs_thread_test:
  test: dscr_sysfs_thread_test
  [cpu 0] User DSCR should be 1 but is 0
  failure: dscr_sysfs_thread_test

So restore non-volatile GPRs after facility unavailable exceptions.

Currently the hypervisor facility unavailable exception is also wired
up to call facility_unavailable_exception().

In practice we should never take a hypervisor facility unavailable
exception for the DSCR. On older bare metal systems we set HFSCR_DSCR
unconditionally in __init_HFSCR, or on newer systems it should be
enabled via the "data-stream-control-register" device tree CPU
feature.

Even if it's not, since commit f3c99f97a3cd ("KVM: PPC: Book3S HV:
Don't access HFSCR, LPIDR or LPCR when running nested"), the KVM code
has unconditionally set HFSCR_DSCR when running guests.

So we should only get a hypervisor facility unavailable for the DSCR
if skiboot has disabled the "data-stream-control-register" feature,
and we are somehow in guest context but not via KVM.

Given all that, it should be unnecessary to add a restore of
non-volatile GPRs after the hypervisor facility exception, because we
never expect to hit that path. But equally we may as well add the
restore, because we never expect to hit that path, and if we ever did,
at least we would correctly restore the registers to their post
emulation state.

In future we can split the non-HV and HV facility unavailable handling
so that there is no emulation in the HV handler, and then remove the
restore for the HV case.

Fixes: 702f09805222 ("powerpc/64s/exception: Remove lite interrupt return")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200526061808.2472279-1-mpe@ellerman.id.au
1 parent 8659a0e
Raw File
Tip revision: 595d153dd1022392083ac93a1550382cbee127e0 authored by Michael Ellerman on 26 May 2020, 06:18:08 UTC
powerpc/64s: Fix restore of NV GPRs after facility unavailable exception
Tip revision: 595d153
.mailmap
#
# This list is used by git-shortlog to fix a few botched name translations
# in the git archive, either because the author's full name was messed up
# and/or not always written the same way, making contributions from the
# same person appearing not to be so or badly displayed.
#
# repo-abbrev: /pub/scm/linux/kernel/git/
#

Aaron Durbin <adurbin@google.com>
Adam Oldham <oldhamca@gmail.com>
Adam Radford <aradford@gmail.com>
Adrian Bunk <bunk@stusta.de>
Adriana Reus <adi.reus@gmail.com> <adriana.reus@intel.com>
Alan Cox <alan@lxorguk.ukuu.org.uk>
Alan Cox <root@hraefn.swansea.linux.org.uk>
Aleksey Gorelov <aleksey_gorelov@phoenix.com>
Aleksandar Markovic <aleksandar.markovic@mips.com> <aleksandar.markovic@imgtec.com>
Alex Shi <alex.shi@linux.alibaba.com> <alex.shi@intel.com>
Alex Shi <alex.shi@linux.alibaba.com> <alex.shi@linaro.org>
Alexandre Belloni <alexandre.belloni@bootlin.com> <alexandre.belloni@free-electrons.com>
Alexei Starovoitov <ast@kernel.org> <ast@plumgrid.com>
Alexei Starovoitov <ast@kernel.org> <alexei.starovoitov@gmail.com>
Alexei Starovoitov <ast@kernel.org> <ast@fb.com>
Al Viro <viro@ftp.linux.org.uk>
Al Viro <viro@zenIV.linux.org.uk>
Andi Shyti <andi@etezian.org> <andi.shyti@samsung.com>
Andreas Herrmann <aherrman@de.ibm.com>
Andrey Ryabinin <ryabinin.a.a@gmail.com> <a.ryabinin@samsung.com>
Andrew Morton <akpm@linux-foundation.org>
Andrew Murray <amurray@thegoodpenguin.co.uk> <andrew.murray@arm.com>
Andrew Murray <amurray@thegoodpenguin.co.uk> <amurray@embedded-bits.co.uk>
Andrew Vasquez <andrew.vasquez@qlogic.com>
Andy Adamson <andros@citi.umich.edu>
Antoine Tenart <antoine.tenart@free-electrons.com>
Antonio Ospite <ao2@ao2.it> <ao2@amarulasolutions.com>
Archit Taneja <archit@ti.com>
Ard Biesheuvel <ardb@kernel.org> <ard.biesheuvel@linaro.org>
Arnaud Patard <arnaud.patard@rtp-net.org>
Arnd Bergmann <arnd@arndb.de>
Axel Dyks <xl@xlsigned.net>
Axel Lin <axel.lin@gmail.com>
Bart Van Assche <bvanassche@acm.org> <bart.vanassche@wdc.com>
Bart Van Assche <bvanassche@acm.org> <bart.vanassche@sandisk.com>
Ben Gardner <bgardner@wabtec.com>
Ben M Cahill <ben.m.cahill@intel.com>
Björn Steinbrink <B.Steinbrink@gmx.de>
Boris Brezillon <bbrezillon@kernel.org> <boris.brezillon@bootlin.com>
Boris Brezillon <bbrezillon@kernel.org> <boris.brezillon@free-electrons.com>
Boris Brezillon <bbrezillon@kernel.org> <b.brezillon.dev@gmail.com>
Boris Brezillon <bbrezillon@kernel.org> <b.brezillon@overkiz.com>
Brian Avery <b.avery@hp.com>
Brian King <brking@us.ibm.com>
Chao Yu <chao@kernel.org> <chao2.yu@samsung.com>
Chao Yu <chao@kernel.org> <yuchao0@huawei.com>
Christoph Hellwig <hch@lst.de>
Christophe Ricard <christophe.ricard@gmail.com>
Corey Minyard <minyard@acm.org>
Damian Hobson-Garcia <dhobsong@igel.co.jp>
Daniel Borkmann <daniel@iogearbox.net> <dborkman@redhat.com>
Daniel Borkmann <daniel@iogearbox.net> <dborkmann@redhat.com>
Daniel Borkmann <daniel@iogearbox.net> <danborkmann@iogearbox.net>
Daniel Borkmann <daniel@iogearbox.net> <daniel.borkmann@tik.ee.ethz.ch>
Daniel Borkmann <daniel@iogearbox.net> <danborkmann@googlemail.com>
Daniel Borkmann <daniel@iogearbox.net> <dxchgb@gmail.com>
David Brownell <david-b@pacbell.net>
David Woodhouse <dwmw2@shinybook.infradead.org>
Dengcheng Zhu <dzhu@wavecomp.com> <dengcheng.zhu@mips.com>
Dengcheng Zhu <dzhu@wavecomp.com> <dengcheng.zhu@imgtec.com>
Dengcheng Zhu <dzhu@wavecomp.com> <dczhu@mips.com>
Dengcheng Zhu <dzhu@wavecomp.com> <dengcheng.zhu@gmail.com>
<dev.kurt@vandijck-laurijssen.be> <kurt.van.dijck@eia.be>
Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Dmitry Safonov <0x7f454c46@gmail.com> <dsafonov@virtuozzo.com>
Dmitry Safonov <0x7f454c46@gmail.com> <d.safonov@partner.samsung.com>
Dmitry Safonov <0x7f454c46@gmail.com> <dima@arista.com>
Domen Puncer <domen@coderock.org>
Douglas Gilbert <dougg@torque.net>
Ed L. Cashin <ecashin@coraid.com>
Erik Kaneda <erik.kaneda@intel.com> <erik.schmauss@intel.com>
Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Felipe W Damasio <felipewd@terra.com.br>
Felix Kuhling <fxkuehl@gmx.de>
Felix Moeller <felix@derklecks.de>
Filipe Lautert <filipe@icewall.org>
Franck Bui-Huu <vagabon.xyz@gmail.com>
Frank Rowand <frowand.list@gmail.com> <frowand@mvista.com>
Frank Rowand <frowand.list@gmail.com> <frank.rowand@am.sony.com>
Frank Rowand <frowand.list@gmail.com> <frank.rowand@sonymobile.com>
Frank Zago <fzago@systemfabricworks.com>
Gao Xiang <xiang@kernel.org> <gaoxiang25@huawei.com>
Gao Xiang <xiang@kernel.org> <hsiangkao@aol.com>
Greg Kroah-Hartman <greg@echidna.(none)>
Greg Kroah-Hartman <gregkh@suse.de>
Greg Kroah-Hartman <greg@kroah.com>
Gregory CLEMENT <gregory.clement@bootlin.com> <gregory.clement@free-electrons.com>
Hanjun Guo <guohanjun@huawei.com> <hanjun.guo@linaro.org>
Henk Vergonet <Henk.Vergonet@gmail.com>
Henrik Kretzschmar <henne@nachtwindheim.de>
Henrik Rydberg <rydberg@bitmath.org>
Herbert Xu <herbert@gondor.apana.org.au>
Jacob Shin <Jacob.Shin@amd.com>
Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk@google.com>
Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk@motorola.com>
Jaegeuk Kim <jaegeuk@kernel.org> <jaegeuk.kim@samsung.com>
Jakub Kicinski <kuba@kernel.org> <jakub.kicinski@netronome.com>
James Bottomley <jejb@mulgrave.(none)>
James Bottomley <jejb@titanic.il.steeleye.com>
James E Wilson <wilson@specifix.com>
James Hogan <jhogan@kernel.org> <james.hogan@imgtec.com>
James Hogan <jhogan@kernel.org> <james@albanarts.com>
James Ketrenos <jketreno@io.(none)>
Jan Glauber <jan.glauber@gmail.com> <jang@de.ibm.com>
Jan Glauber <jan.glauber@gmail.com> <jang@linux.vnet.ibm.com>
Jan Glauber <jan.glauber@gmail.com> <jglauber@cavium.com>
Jason Gunthorpe <jgg@ziepe.ca> <jgg@mellanox.com>
Jason Gunthorpe <jgg@ziepe.ca> <jgunthorpe@obsidianresearch.com>
Javi Merino <javi.merino@kernel.org> <javi.merino@arm.com>
<javier@osg.samsung.com> <javier.martinez@collabora.co.uk>
Jayachandran C <c.jayachandran@gmail.com> <jayachandranc@netlogicmicro.com>
Jayachandran C <c.jayachandran@gmail.com> <jchandra@broadcom.com>
Jayachandran C <c.jayachandran@gmail.com> <jchandra@digeo.com>
Jayachandran C <c.jayachandran@gmail.com> <jnair@caviumnetworks.com>
Jean Tourrilhes <jt@hpl.hp.com>
<jean-philippe@linaro.org> <jean-philippe.brucker@arm.com>
Jeff Garzik <jgarzik@pretzel.yyz.us>
Jeff Layton <jlayton@kernel.org> <jlayton@redhat.com>
Jeff Layton <jlayton@kernel.org> <jlayton@poochiereds.net>
Jeff Layton <jlayton@kernel.org> <jlayton@primarydata.com>
Jens Axboe <axboe@suse.de>
Jens Osterkamp <Jens.Osterkamp@de.ibm.com>
Johan Hovold <johan@kernel.org> <jhovold@gmail.com>
Johan Hovold <johan@kernel.org> <johan@hovoldconsulting.com>
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
John Stultz <johnstul@us.ibm.com>
<josh@joshtriplett.org> <josh@freedesktop.org>
<josh@joshtriplett.org> <josh@kernel.org>
<josh@joshtriplett.org> <josht@linux.vnet.ibm.com>
<josh@joshtriplett.org> <josht@us.ibm.com>
<josh@joshtriplett.org> <josht@vnet.ibm.com>
Juha Yrjola <at solidboot.com>
Juha Yrjola <juha.yrjola@nokia.com>
Juha Yrjola <juha.yrjola@solidboot.com>
Julien Thierry <julien.thierry.kdev@gmail.com> <julien.thierry@arm.com>
Kamil Konieczny <k.konieczny@samsung.com> <k.konieczny@partner.samsung.com>
Kay Sievers <kay.sievers@vrfy.org>
Kenneth W Chen <kenneth.w.chen@intel.com>
Konstantin Khlebnikov <koct9i@gmail.com> <k.khlebnikov@samsung.com>
Koushik <raghavendra.koushik@neterion.com>
Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski@samsung.com>
Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski.k@gmail.com>
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Leon Romanovsky <leon@kernel.org> <leon@leon.nu>
Leon Romanovsky <leon@kernel.org> <leonro@mellanox.com>
Leonid I Ananiev <leonid.i.ananiev@intel.com>
Linas Vepstas <linas@austin.ibm.com>
Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@web.de>
Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@ascom.ch>
Li Yang <leoyang.li@nxp.com> <leo@zh-kernel.org>
Li Yang <leoyang.li@nxp.com> <leoli@freescale.com>
Lukasz Luba <lukasz.luba@arm.com> <l.luba@partner.samsung.com>
Maciej W. Rozycki <macro@mips.com> <macro@imgtec.com>
Marc Zyngier <maz@kernel.org> <marc.zyngier@arm.com>
Marcin Nowakowski <marcin.nowakowski@mips.com> <marcin.nowakowski@imgtec.com>
Mark Brown <broonie@sirena.org.uk>
Mark Yao <markyao0591@gmail.com> <mark.yao@rock-chips.com>
Martin Kepplinger <martink@posteo.de> <martin.kepplinger@theobroma-systems.com>
Martin Kepplinger <martink@posteo.de> <martin.kepplinger@ginzinger.com>
Martin Kepplinger <martink@posteo.de> <martin.kepplinger@puri.sm>
Mathieu Othacehe <m.othacehe@gmail.com>
Matthew Wilcox <willy@infradead.org> <matthew.r.wilcox@intel.com>
Matthew Wilcox <willy@infradead.org> <matthew@wil.cx>
Matthew Wilcox <willy@infradead.org> <mawilcox@linuxonhyperv.com>
Matthew Wilcox <willy@infradead.org> <mawilcox@microsoft.com>
Matthew Wilcox <willy@infradead.org> <willy@debian.org>
Matthew Wilcox <willy@infradead.org> <willy@linux.intel.com>
Matthew Wilcox <willy@infradead.org> <willy@parisc-linux.org>
Matthieu CASTET <castet.matthieu@free.fr>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@brturbo.com.br>
Mauro Carvalho Chehab <mchehab@kernel.org> <maurochehab@gmail.com>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@infradead.org>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@redhat.com>
Mauro Carvalho Chehab <mchehab@kernel.org> <m.chehab@samsung.com>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@osg.samsung.com>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@s-opensource.com>
Matt Ranostay <mranostay@gmail.com> Matthew Ranostay <mranostay@embeddedalley.com>
Matt Ranostay <mranostay@gmail.com> <matt.ranostay@intel.com>
Matt Ranostay <matt.ranostay@konsulko.com> <matt@ranostay.consulting>
Matt Redfearn <matt.redfearn@mips.com> <matt.redfearn@imgtec.com>
Maxime Ripard <mripard@kernel.org> <maxime.ripard@bootlin.com>
Maxime Ripard <mripard@kernel.org> <maxime.ripard@free-electrons.com>
Mayuresh Janorkar <mayur@ti.com>
Michael Buesch <m@bues.ch>
Michel Dänzer <michel@tungstengraphics.com>
Miodrag Dinic <miodrag.dinic@mips.com> <miodrag.dinic@imgtec.com>
Miquel Raynal <miquel.raynal@bootlin.com> <miquel.raynal@free-electrons.com>
Mitesh shah <mshah@teja.com>
Mohit Kumar <mohit.kumar@st.com> <mohit.kumar.dhaka@gmail.com>
Morten Welinder <terra@gnome.org>
Morten Welinder <welinder@anemone.rentec.com>
Morten Welinder <welinder@darter.rentec.com>
Morten Welinder <welinder@troll.com>
Mythri P K <mythripk@ti.com>
Nguyen Anh Quynh <aquynh@gmail.com>
Nicolas Ferre <nicolas.ferre@microchip.com> <nicolas.ferre@atmel.com>
Nicolas Pitre <nico@fluxnic.net> <nicolas.pitre@linaro.org>
Nicolas Pitre <nico@fluxnic.net> <nico@linaro.org>
Oleksij Rempel <linux@rempel-privat.de> <bug-track@fisher-privat.net>
Oleksij Rempel <linux@rempel-privat.de> <external.Oleksij.Rempel@de.bosch.com>
Oleksij Rempel <linux@rempel-privat.de> <fixed-term.Oleksij.Rempel@de.bosch.com>
Oleksij Rempel <linux@rempel-privat.de> <o.rempel@pengutronix.de>
Oleksij Rempel <linux@rempel-privat.de> <ore@pengutronix.de>
Pali Rohár <pali@kernel.org> <pali.rohar@gmail.com>
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Patrick Mochel <mochel@digitalimplant.org>
Paul Burton <paulburton@kernel.org> <paul.burton@imgtec.com>
Paul Burton <paulburton@kernel.org> <paul.burton@mips.com>
Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.ibm.com>
Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.vnet.ibm.com>
Paul E. McKenney <paulmck@kernel.org> <paul.mckenney@linaro.org>
Paul E. McKenney <paulmck@kernel.org> <paulmck@us.ibm.com>
Peter A Jonsson <pj@ludd.ltu.se>
Peter Oruba <peter@oruba.de>
Peter Oruba <peter.oruba@amd.com>
Pratyush Anand <pratyush.anand@gmail.com> <pratyush.anand@st.com>
Praveen BP <praveenbp@ti.com>
Punit Agrawal <punitagrawal@gmail.com> <punit.agrawal@arm.com>
Qais Yousef <qsyousef@gmail.com> <qais.yousef@imgtec.com>
Quentin Monnet <quentin@isovalent.com> <quentin.monnet@netronome.com>
Quentin Perret <qperret@qperret.net> <quentin.perret@arm.com>
Rafael J. Wysocki <rjw@rjwysocki.net> <rjw@sisk.pl>
Rajesh Shah <rajesh.shah@intel.com>
Ralf Baechle <ralf@linux-mips.org>
Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
Randy Dunlap <rdunlap@infradead.org> <rdunlap@xenotime.net>
Rémi Denis-Courmont <rdenis@simphalempin.com>
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Ross Zwisler <zwisler@kernel.org> <ross.zwisler@linux.intel.com>
Rudolf Marek <R.Marek@sh.cvut.cz>
Rui Saraiva <rmps@joel.ist.utl.pt>
Sachin P Sant <ssant@in.ibm.com>
Sarangdhar Joshi <spjoshi@codeaurora.org>
Sam Ravnborg <sam@mars.ravnborg.org>
Santosh Shilimkar <ssantosh@kernel.org>
Santosh Shilimkar <santosh.shilimkar@oracle.org>
Sascha Hauer <s.hauer@pengutronix.de>
S.Çağlar Onur <caglar@pardus.org.tr>
Sakari Ailus <sakari.ailus@linux.intel.com> <sakari.ailus@iki.fi>
Sean Nyekjaer <sean@geanix.com> <sean.nyekjaer@prevas.dk>
Sebastian Reichel <sre@kernel.org> <sre@debian.org>
Sebastian Reichel <sre@kernel.org> <sebastian.reichel@collabora.co.uk>
Sedat Dilek <sedat.dilek@gmail.com> <sedat.dilek@credativ.de>
Shiraz Hashim <shiraz.linux.kernel@gmail.com> <shiraz.hashim@st.com>
Shuah Khan <shuah@kernel.org> <shuahkhan@gmail.com>
Shuah Khan <shuah@kernel.org> <shuah.khan@hp.com>
Shuah Khan <shuah@kernel.org> <shuahkh@osg.samsung.com>
Shuah Khan <shuah@kernel.org> <shuah.kh@samsung.com>
Simon Arlott <simon@octiron.net> <simon@fire.lp0.eu>
Simon Kelley <simon@thekelleys.org.uk>
Stéphane Witzmann <stephane.witzmann@ubpmes.univ-bpclermont.fr>
Stephen Hemminger <shemminger@osdl.org>
Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Subhash Jadavani <subhashj@codeaurora.org>
Sudeep Holla <sudeep.holla@arm.com> Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Sumit Semwal <sumit.semwal@ti.com>
Tejun Heo <htejun@gmail.com>
Thomas Graf <tgraf@suug.ch>
Thomas Pedersen <twp@codeaurora.org>
Tiezhu Yang <yangtiezhu@loongson.cn> <kernelpatch@126.com>
Todor Tomov <todor.too@gmail.com> <todor.tomov@linaro.org>
Tony Luck <tony.luck@intel.com>
TripleX Chung <xxx.phy@gmail.com> <zhongyu@18mail.cn>
TripleX Chung <xxx.phy@gmail.com> <triplex@zh-kernel.org>
Tsuneo Yoshioka <Tsuneo.Yoshioka@f-secure.com>
Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Uwe Kleine-König <ukl@pengutronix.de>
Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Vinod Koul <vkoul@kernel.org> <vinod.koul@intel.com>
Vinod Koul <vkoul@kernel.org> <vinod.koul@linux.intel.com>
Vinod Koul <vkoul@kernel.org> <vkoul@infradead.org>
Viresh Kumar <vireshk@kernel.org> <viresh.kumar@st.com>
Viresh Kumar <vireshk@kernel.org> <viresh.linux@gmail.com>
Viresh Kumar <vireshk@kernel.org> <viresh.kumar2@arm.com>
Vivien Didelot <vivien.didelot@gmail.com> <vivien.didelot@savoirfairelinux.com>
Vlad Dogaru <ddvlad@gmail.com> <vlad.dogaru@intel.com>
Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@virtuozzo.com>
Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@parallels.com>
Takashi YOSHII <takashi.yoshii.zj@renesas.com>
Will Deacon <will@kernel.org> <will.deacon@arm.com>
Yakir Yang <kuankuan.y@gmail.com> <ykk@rock-chips.com>
Yusuke Goda <goda.yusuke@renesas.com>
Gustavo Padovan <gustavo@las.ic.unicamp.br>
Gustavo Padovan <padovan@profusion.mobi>
Changbin Du <changbin.du@intel.com> <changbin.du@intel.com>
Changbin Du <changbin.du@intel.com> <changbin.du@gmail.com>
Steve Wise <larrystevenwise@gmail.com> <swise@chelsio.com>
Steve Wise <larrystevenwise@gmail.com> <swise@opengridcomputing.com>
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