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Groups > linux.kernel > #1301827
| From | Jiri Slaby <jslaby@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.12 28/91] x86/cpu: Fix SMAP check in PVOPS environments |
| Date | 2016-01-05 19:10 +0100 |
| Message-ID | <qNEdw-6sw-81@gated-at.bofh.it> (permalink) |
| References | <qNDU6-65D-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Andrew Cooper <andrew.cooper3@citrix.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 581b7f158fe0383b492acd1ce3fb4e99d4e57808 upstream.
There appears to be no formal statement of what pv_irq_ops.save_fl() is
supposed to return precisely. Native returns the full flags, while lguest and
Xen only return the Interrupt Flag, and both have comments by the
implementations stating that only the Interrupt Flag is looked at. This may
have been true when initially implemented, but no longer is.
To make matters worse, the Xen PVOP leaves the upper bits undefined, making
the BUG_ON() undefined behaviour. Experimentally, this now trips for 32bit PV
guests on Broadwell hardware. The BUG_ON() is consistent for an individual
build, but not consistent for all builds. It has also been a sitting timebomb
since SMAP support was introduced.
Use native_save_fl() instead, which will obtain an accurate view of the AC
flag.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Tested-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <lguest@lists.ozlabs.org>
Cc: Xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1433323874-6927-1-git-send-email-andrew.cooper3@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/x86/kernel/cpu/common.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6db4828574ef..9364936b47c2 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -280,10 +280,9 @@ __setup("nosmap", setup_disable_smap);
static __always_inline void setup_smap(struct cpuinfo_x86 *c)
{
- unsigned long eflags;
+ unsigned long eflags = native_save_fl();
/* This should have been cleared long ago */
- raw_local_save_flags(eflags);
BUG_ON(eflags & X86_EFLAGS_AC);
if (cpu_has(c, X86_FEATURE_SMAP)) {
--
2.6.4
--
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[PATCH 3.12 00/91] 3.12.52-stable review Jiri Slaby <jslaby@suse.cz> - 2016-01-05 18:50 +0100
[PATCH 3.12 01/91] ipv6: fix tunnel error handling Jiri Slaby <jslaby@suse.cz> - 2016-01-05 18:50 +0100
[PATCH 3.12 68/91] sctp: use the same clock as if sock source timestamps were on Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 73/91] net: fix IP early demux races Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 62/91] USB: cp210x: Remove CP2110 ID from compatibility list Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 81/91] ahci: add new Intel device IDs Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 75/91] skbuff: Fix offset error in skb_reorder_vlan_header Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 71/91] net: add validation for the socket syscall protocol argument Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 63/91] USB: add quirk for devices with broken LPM Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 57/91] nfs4: start callback_ident at idr 1 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 58/91] nfs: if we have no valid attrs, then don't declare the attribute cache valid Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 74/91] vlan: Fix untag operations of stacked vlans with REORDER_HEADER off Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 48/91] netfilter: ipt_rpfilter: remove the nh_scope test in rpfilter_lookup_reverse Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 86/91] i2c: i801: add Intel Lewisburg device IDs Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 61/91] USB: serial: Another Infineon flash loader USB ID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 51/91] ip6mr: call del_timer_sync() in ip6mr_free_table() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 60/91] USB: cdc_acm: Ignore Infineon Flash Loader utility Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 77/91] bluetooth: Validate socket address length in sco_sock_bind(). Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 65/91] usb: Use the USB_SS_MULT() macro to decode burst multiplier for log message Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 69/91] sctp: update the netstamp_needed counter when copying sockets Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 72/91] sh_eth: fix kernel oops in skb_put() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 64/91] USB: whci-hcd: add check for dma mapping error Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 76/91] pptp: verify sockaddr_len in pptp_bind() and pptp_connect() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 91/91] HID: dragonrise: fix HID Descriptor for 0x0006 PID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 87/91] cdrom: Random writing support for BD-RE media Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 70/91] ipv6: sctp: clone options to avoid use after free Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 59/91] ocfs2: fix umask ignored issue Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 67/91] atl1c: Improve driver not to do order 4 GFP_ATOMIC allocation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 85/91] i2c: i801: Add support for Intel Broxton Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 82/91] target/stat: print full t10_wwn.model buffer Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 90/91] gpio/omap: raw read and write endian fix Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
[PATCH 3.12 36/91] can: sja1000: clear interrupts on start Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 29/91] mac80211: fix driver RSSI event calculations Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 38/91] usblp: do not set TASK_INTERRUPTIBLE before lock Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 47/91] module: Call module notifier on failure after complete_formation() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 27/91] x86/cpu: Call verify_cpu() after having entered long mode too Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 32/91] staging: rtl8712: Add device ID for Sitecom WLA2100 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 41/91] USB: serial: option: add support for Novatel MiFi USB620L Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 56/91] firewire: ohci: fix JMicron JMB38x IT context discovery Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 46/91] tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 37/91] arm64: Fix compat register mappings Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 30/91] net: mvneta: Fix CPU_MAP registers initialisation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 26/91] x86/setup: Fix low identity map for >= 2GB kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 53/91] Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 55/91] ext4, jbd2: ensure entering into panic after recording an error in superblock Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 66/91] gre6: allow to update all parameters via rtnl Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 43/91] ALSA: usb-audio: add packet size quirk for the Medeli DD305 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 54/91] ext4: fix potential use after free in __ext4_journal_stop Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 24/91] ARM: common: edma: Fix channel parameter for irq callbacks Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 14/91] net: ipmr: fix static mfc/dev leaks on table destruction Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 39/91] usb: musb: core: fix order of arguments to ulpi write callback Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 45/91] ALSA: usb-audio: work around CH345 input SysEx corruption Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 40/91] USB: ti_usb_3410_5052: Add Honeywell HGI80 ID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 31/91] mwifiex: fix mwifiex_rdeeprom_read() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 52/91] Btrfs: fix race leading to incorrect item deletion when dropping extents Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 33/91] Bluetooth: hidp: fix device disconnect on idle timeout Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Paolo Bonzini <pbonzini@redhat.com> - 2016-01-06 11:50 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-06 12:10 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-06 12:30 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-06 14:40 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-06 15:30 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-08 13:00 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-08 14:40 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-09 08:10 +0100
Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Kamal Mostafa <kamal@canonical.com> - 2016-01-14 22:00 +0100
[PATCH 3.12 34/91] Bluetooth: ath3k: Add new AR3012 0930:021c id Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 44/91] ALSA: usb-audio: prevent CH345 multiport output SysEx corruption Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 35/91] Bluetooth: ath3k: Add support of AR3012 0cf3:817b device Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 28/91] x86/cpu: Fix SMAP check in PVOPS environments Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 49/91] netfilter: ip6t_SYNPROXY: fix NULL pointer dereference Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 42/91] USB: option: add XS Stick W100-2 from 4G Systems Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
[PATCH 3.12 10/91] net: qmi_wwan: add XS Stick W100-2 from 4G Systems Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 11/91] tcp: md5: fix lockdep annotation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 19/91] net/neighbour: fix crash at dumping device-agnostic proxy entries Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 23/91] ARM: 8427/1: dma-mapping: add support for offset parameter in dma_mmap() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 07/91] packet: infer protocol from ethernet header if unset Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 21/91] Bluetooth: ath3k: Add support of 04ca:300d AR3012 device Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 08/91] sctp: translate host order to network order when setting a hmacid Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 22/91] ARM: 8426/1: dma-mapping: add missing range check in dma_mmap() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 05/91] unix: avoid use-after-free in ep_remove_wait_queue Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 02/91] MIPS: KVM: Fix ASID restoration logic Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 20/91] ipv6: sctp: implement sctp_v6_destroy_sock() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 13/91] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 18/91] ipv6: add complete rcu protection around np->opt Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 12/91] tcp: initialize tp->copied_seq in case of cross SYN connection Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 04/91] MIPS: KVM: Uninit VCPU in vcpu_create error path Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
[PATCH 3.12 06/91] packet: do skb_probe_transport_header when we actually have data Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
Re: [PATCH 3.12 00/91] 3.12.52-stable review Guenter Roeck <linux@roeck-us.net> - 2016-01-05 21:50 +0100
Re: [PATCH 3.12 00/91] 3.12.52-stable review Jiri Slaby <jslaby@suse.cz> - 2016-01-09 09:50 +0100
Re: [PATCH 3.12 00/91] 3.12.52-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2016-01-05 22:20 +0100
Re: [PATCH 3.12 00/91] 3.12.52-stable review Nikolay Borisov <kernel@kyup.com> - 2016-01-06 08:40 +0100
Re: [PATCH 3.12 00/91] 3.12.52-stable review Greg KH <gregkh@linuxfoundation.org> - 2016-01-06 09:20 +0100
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