All of lore.kernel.org
 help / color / mirror / Atom feed
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
	kvm@vger.kernel.org
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jon Masters <jcm@redhat.com>, Marcus Meissner <meissner@suse.de>,
	Jiri Kosina <jkosina@suse.cz>
Subject: [PATCH 6/6] s390: scrub registers on kernel entry and KVM exit
Date: Wed, 17 Jan 2018 10:48:39 +0100	[thread overview]
Message-ID: <1516182519-10623-7-git-send-email-schwidefsky@de.ibm.com> (raw)
In-Reply-To: <1516182519-10623-1-git-send-email-schwidefsky@de.ibm.com>

Clear all user space registers on entry to the kernel and all KVM guest
registers on KVM guest exit if the register does not contain either a
parameter or a result value.

Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/kernel/entry.S | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 2a22c03..47227d3 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -322,6 +322,12 @@ ENTRY(sie64a)
 sie_exit:
 	lg	%r14,__SF_EMPTY+8(%r15)		# load guest register save area
 	stmg	%r0,%r13,0(%r14)		# save guest gprs 0-13
+	xgr	%r0,%r0				# clear guest registers
+	xgr	%r1,%r1
+	xgr	%r2,%r2
+	xgr	%r3,%r3
+	xgr	%r4,%r4
+	xgr	%r5,%r5
 	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers
 	lg	%r2,__SF_EMPTY+16(%r15)		# return exit reason code
 	br	%r14
@@ -358,6 +364,7 @@ ENTRY(system_call)
 	UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
 	BPENTER __TI_flags(%r12),_TIF_NOBP
 	stmg	%r0,%r7,__PT_R0(%r11)
+	xgr	%r0,%r0
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
 	mvc	__PT_PSW(16,%r11),__LC_SVC_OLD_PSW
 	mvc	__PT_INT_CODE(4,%r11),__LC_SVC_ILC
@@ -640,6 +647,14 @@ ENTRY(pgm_check_handler)
 4:	lgr	%r13,%r11
 	la	%r11,STACK_FRAME_OVERHEAD(%r15)
 	stmg	%r0,%r7,__PT_R0(%r11)
+	xgr	%r0,%r0			# clear user space registers
+	xgr	%r1,%r1
+	xgr	%r2,%r2
+	xgr	%r3,%r3
+	xgr	%r4,%r4
+	xgr	%r5,%r5
+	xgr	%r6,%r6
+	xgr	%r7,%r7
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	mvc	__PT_INT_CODE(4,%r11),__LC_PGM_ILC
@@ -706,6 +721,15 @@ ENTRY(io_int_handler)
 	lmg	%r8,%r9,__LC_IO_OLD_PSW
 	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
 	stmg	%r0,%r7,__PT_R0(%r11)
+	xgr	%r0,%r0			# clear user space registers
+	xgr	%r1,%r1
+	xgr	%r2,%r2
+	xgr	%r3,%r3
+	xgr	%r4,%r4
+	xgr	%r5,%r5
+	xgr	%r6,%r6
+	xgr	%r7,%r7
+	xgr	%r10,%r10
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	mvc	__PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
@@ -924,6 +948,15 @@ ENTRY(ext_int_handler)
 	lmg	%r8,%r9,__LC_EXT_OLD_PSW
 	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
 	stmg	%r0,%r7,__PT_R0(%r11)
+	xgr	%r0,%r0			# clear user space registers
+	xgr	%r1,%r1
+	xgr	%r2,%r2
+	xgr	%r3,%r3
+	xgr	%r4,%r4
+	xgr	%r5,%r5
+	xgr	%r6,%r6
+	xgr	%r7,%r7
+	xgr	%r10,%r10
 	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	lghi	%r1,__LC_EXT_PARAMS2
@@ -1133,6 +1166,14 @@ ENTRY(mcck_int_handler)
 .Lmcck_skip:
 	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
 	stmg	%r0,%r7,__PT_R0(%r11)
+	xgr	%r0,%r0			# clear user space registers
+	xgr	%r2,%r2
+	xgr	%r3,%r3
+	xgr	%r4,%r4
+	xgr	%r5,%r5
+	xgr	%r6,%r6
+	xgr	%r7,%r7
+	xgr	%r10,%r10
 	mvc	__PT_R8(64,%r11),0(%r14)
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
-- 
2.7.4

  parent reply	other threads:[~2018-01-17  9:49 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-17  9:48 [PATCH 0/6] s390: improve speculative execution handling Martin Schwidefsky
2018-01-17  9:48 ` [PATCH 1/6] s390/alternative: use a copy of the facility bit mask Martin Schwidefsky
2018-01-17 13:54   ` David Hildenbrand
2018-01-17 14:24   ` Cornelia Huck
2018-01-17  9:48 ` [PATCH 2/6] s390: implement nospec_[load|ptr] Martin Schwidefsky
2018-01-17 12:41   ` Jiri Kosina
2018-01-17 14:52     ` Jon Masters
2018-01-17 13:58   ` David Hildenbrand
2018-01-17 14:04     ` Christian Borntraeger
2018-01-17  9:48 ` [PATCH 3/6] s390: add options to change branch prediction behaviour for the kernel Martin Schwidefsky
2018-01-18  9:52   ` Cornelia Huck
2018-01-19  4:53   ` QingFeng Hao
2018-01-17  9:48 ` [PATCH 4/6] s390: add system call to run tasks with modified branch prediction Martin Schwidefsky
2018-01-17 10:03   ` Florian Weimer
2018-01-17 10:05     ` Paolo Bonzini
2018-01-17 11:14     ` Christian Borntraeger
2018-01-17 11:50       ` Paolo Bonzini
2018-01-17 11:55       ` Martin Schwidefsky
2018-01-17 13:25         ` Heiko Carstens
2018-01-17  9:48 ` [PATCH 5/6] KVM: s390: wire up seb feature Martin Schwidefsky
2018-01-17 11:18   ` Christian Borntraeger
2018-01-17 11:22     ` Paolo Bonzini
2018-01-17 11:28       ` Christian Borntraeger
2018-01-17 11:29         ` Christian Borntraeger
2018-01-17 11:32           ` Paolo Bonzini
2018-01-17 11:33   ` David Hildenbrand
2018-01-17 11:39     ` Christian Borntraeger
2018-01-17 13:44   ` [PATCH v2] KVM: s390: wire up bpb feature Christian Borntraeger
2018-01-17 13:51     ` David Hildenbrand
2018-01-17 21:43       ` Christian Borntraeger
2018-01-18  6:27         ` Martin Schwidefsky
2018-01-18  9:59     ` Cornelia Huck
2018-01-18 10:09       ` Christian Borntraeger
2018-01-17  9:48 ` Martin Schwidefsky [this message]
2018-01-19  6:29   ` [PATCH 6/6] s390: scrub registers on kernel entry and KVM exit QingFeng Hao
2018-01-19  7:57     ` Christian Borntraeger
2018-01-19  8:27       ` QingFeng Hao
2018-01-17 12:00 ` [PATCH 0/6] s390: improve speculative execution handling Cornelia Huck
2018-01-17 12:05   ` Christian Borntraeger
2018-01-17 13:29 ` Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1516182519-10623-7-git-send-email-schwidefsky@de.ibm.com \
    --to=schwidefsky@de.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=heiko.carstens@de.ibm.com \
    --cc=jcm@redhat.com \
    --cc=jkosina@suse.cz \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=meissner@suse.de \
    --cc=pbonzini@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.