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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: [PATCH 3.4 05/25] s390: fix kernel crash due to linkage stack instructions
Date: Thu, 20 Feb 2014 15:51:21 -0800	[thread overview]
Message-ID: <20140220234842.635275506@linuxfoundation.org> (raw)
In-Reply-To: <20140220234842.483343851@linuxfoundation.org>

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

commit 8d7f6690cedb83456edd41c9bd583783f0703bf0 upstream.

The kernel currently crashes with a low-address-protection exception
if a user space process executes an instruction that tries to use the
linkage stack. Set the base-ASTE origin and the subspace-ASTE origin
of the dispatchable-unit-control-table to point to a dummy ASTE.
Set up control register 15 to point to an empty linkage stack with no
room left.

A user space process with a linkage stack instruction will still crash
but with a different exception which is correctly translated to a
segmentation fault instead of a kernel oops.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/s390/kernel/head64.S |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -61,7 +61,7 @@ ENTRY(startup_continue)
 	.quad	0			# cr12: tracing off
 	.quad	0			# cr13: home space segment table
 	.quad	0xc0000000		# cr14: machine check handling off
-	.quad	0			# cr15: linkage stack operations
+	.quad	.Llinkage_stack		# cr15: linkage stack operations
 .Lpcmsk:.quad	0x0000000180000000
 .L4malign:.quad 0xffffffffffc00000
 .Lscan2g:.quad	0x80000000 + 0x20000 - 8	# 2GB + 128K - 8
@@ -69,12 +69,15 @@ ENTRY(startup_continue)
 .Lparmaddr:
 	.quad	PARMAREA
 	.align	64
-.Lduct: .long	0,0,0,0,.Lduald,0,0,0
+.Lduct: .long	0,.Laste,.Laste,0,.Lduald,0,0,0
 	.long	0,0,0,0,0,0,0,0
+.Laste:	.quad	0,0xffffffffffffffff,0,0,0,0,0,0
 	.align	128
 .Lduald:.rept	8
 	.long	0x80000000,0,0,0	# invalid access-list entries
 	.endr
+.Llinkage_stack:
+	.long	0,0,0x89000000,0,0,0,0x8a000000,0
 
 ENTRY(_ehead)
 



  parent reply	other threads:[~2014-02-20 23:51 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-20 23:51 [PATCH 3.4 00/25] 3.4.82-stable review Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 01/25] xen-blkfront: handle backend CLOSED without CLOSING Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 02/25] fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmem Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 03/25] mac80211: fix fragmentation code, particularly for encryption Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 04/25] s390/dump: Fix dump memory detection Greg Kroah-Hartman
2014-02-20 23:51 ` Greg Kroah-Hartman [this message]
2014-02-20 23:51 ` [PATCH 3.4 06/25] spi: Fix crash with double message finalisation on error handling Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 07/25] raw: test against runtime value of max_raw_minors Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 08/25] lockd: send correct lock when granting a delayed lock Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 09/25] tty: n_gsm: Fix for modems with brk in modem status control Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 10/25] staging:iio:ad799x fix error_free_irq which was freeing an irq that may not have been requested Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 12/25] USB: ftdi_sio: add Tagsys RFID Reader IDs Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 13/25] usb-storage: add unusual-devs entry for BlackBerry 9000 Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 14/25] usb-storage: restrict bcdDevice range for Super Top in Cypress ATACB Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 15/25] usb-storage: enable multi-LUN scanning when needed Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 16/25] usb: option: blacklist ZTE MF667 net interface Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 17/25] Modpost: fixed USB alias generation for ranges including 0x9 and 0xA Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 18/25] block: add cond_resched() to potentially long running ioctl discard loop Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 19/25] IB/qib: Add missing serdes init sequence Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 20/25] KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio() Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 21/25] md/raid5: Fix CPU hotplug callback registration Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 22/25] time: Fix overflow when HZ is smaller than 60 Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 23/25] power: max17040: Fix NULL pointer dereference when there is no platform_data Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 24/25] ring-buffer: Fix first commit on sub-buffer having non-zero delta Greg Kroah-Hartman
2014-02-20 23:51 ` [PATCH 3.4 25/25] genirq: Add missing irq_to_desc export for CONFIG_SPARSE_IRQ=n Greg Kroah-Hartman
2014-02-21  5:05 ` [PATCH 3.4 00/25] 3.4.82-stable review Guenter Roeck
2014-02-21 23:40 ` Shuah Khan
2014-02-22 20:45   ` Greg KH

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