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Groups > linux.kernel > #1235228
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.14 81/84] x86/nmi/64: Reorder nested NMI checks |
| Date | 2015-09-29 17:30 +0200 |
| Message-ID | <qe50S-1Za-7@gated-at.bofh.it> (permalink) |
| References | <qe4Rd-1Nk-47@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski <luto@kernel.org> commit a27507ca2d796cfa8d907de31ad730359c8a6d06 upstream. Check the repeat_nmi .. end_repeat_nmi special case first. The next patch will rework the RSP check and, as a side effect, the RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so we'll need this ordering of the checks. Note: this is more subtle than it appears. The check for repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code instead of adjusting the "iret" frame to force a repeat. This is necessary, because the code between repeat_nmi and end_repeat_nmi sets "NMI executing" and then writes to the "iret" frame itself. If a nested NMI comes in and modifies the "iret" frame while repeat_nmi is also modifying it, we'll end up with garbage. The old code got this right, as does the new code, but the new code is a bit more explicit. If we were to move the check right after the "NMI executing" check, then we'd get it wrong and have random crashes. ( Because the "NMI executing" check would jump to the code that would modify the "iret" frame without checking if the interrupted NMI was currently modifying it. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/kernel/entry_64.S | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1842,7 +1842,23 @@ ENTRY(nmi) /* * Determine whether we're a nested NMI. * - * First check "NMI executing". If it's set, then we're nested. + * If we interrupted kernel code between repeat_nmi and + * end_repeat_nmi, then we are a nested NMI. We must not + * modify the "iret" frame because it's being written by + * the outer NMI. That's okay; the outer NMI handler is + * about to about to call do_nmi anyway, so we can just + * resume the outer NMI. + */ + movq $repeat_nmi, %rdx + cmpq 8(%rsp), %rdx + ja 1f + movq $end_repeat_nmi, %rdx + cmpq 8(%rsp), %rdx + ja nested_nmi_out +1: + + /* + * Now check "NMI executing". If it's set, then we're nested. * This will not detect if we interrupted an outer NMI just * before IRET. */ @@ -1860,21 +1876,6 @@ ENTRY(nmi) nested_nmi: /* - * If we interrupted an NMI that is between repeat_nmi and - * end_repeat_nmi, then we must not modify the "iret" frame - * because it's being written by the outer NMI. That's okay; - * the outer NMI handler is about to call do_nmi anyway, - * so we can just resume the outer NMI. - */ - movq $repeat_nmi, %rdx - cmpq 8(%rsp), %rdx - ja 1f - movq $end_repeat_nmi, %rdx - cmpq 8(%rsp), %rdx - ja nested_nmi_out - -1: - /* * Modify the "iret" frame to point to repeat_nmi, forcing another * iteration of NMI handling. */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 3.14 00/84] 3.14.54-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:20 +0200
[PATCH 3.14 01/84] blk-mq: fix buffer overflow when reading sysfs file of pending Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:20 +0200
[PATCH 3.14 07/84] arm64: compat: fix vfp save/restore across signal handlers in big-endian Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 08/84] arm64: head.S: initialise mdcr_el2 in el2_setup Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 81/84] x86/nmi/64: Reorder nested NMI checks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 83/84] udf: Check length of extended attributes and allocation descriptors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 72/84] rds: fix an integer overflow test in rds_info_getsockopt() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 63/84] ip6_gre: release cached dst on tunnel removal Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 60/84] inet: frags: fix defragmented packets IP header for af_packet Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 80/84] x86/nmi/64: Improve nested NMI comments Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 75/84] net: gso: use feature flag argument in all protocol gso handlers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 03/84] rtlwifi: rtl8192cu: Add new device ID Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 02/84] unshare: Unsharing a thread does not require unsharing a vm Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 52/84] net: Clone skb before setting peeked flag Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 69/84] openvswitch: Zero flows on allocation. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 82/84] x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detection Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 67/84] netlink, mmap: transform mmap skb into full skb on taps Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 38/84] IB/mlx4: Forbid using sysfs to change RoCE pkeys Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 70/84] fib_rules: fix fib rule dumps across multiple skbs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 79/84] x86/nmi/64: Switch stacks on userspace NMI entry Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
Re: [PATCH 3.14 79/84] x86/nmi/64: Switch stacks on userspace NMI entry Andy Lutomirski <luto@amacapital.net> - 2015-09-29 19:30 +0200
Re: [PATCH 3.14 79/84] x86/nmi/64: Switch stacks on userspace NMI entry Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 20:00 +0200
[PATCH 3.14 58/84] bonding: fix destruction of bond with devices different from arphrd_ether Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 47/84] net/tipc: initialize security state for new connection socket Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 55/84] bridge: mdb: fix double add notification Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 06/84] arm64: kconfig: Move LIST_POISON to a safe value Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 78/84] x86/nmi/64: Remove asm code that saves CR2 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 62/84] net/mlx4_core: Fix wrong index in propagating port change event to VFs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 14/84] powerpc/mm: Fix pte_pagesize_index() crash on 4K w/64K hash Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 84/84] NVMe: Initialize device reference count earlier Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 59/84] bonding: correct the MAC address for "follow" fail_over_mac policy Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 12/84] ALSA: hda - Enable headphone jack detect on old Fujitsu laptops Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 76/84] Revert "iio: bmg160: IIO_BUFFER and IIO_TRIGGERED_BUFFER are required" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 29/84] vmscan: fix increasing nr_isolated incurred by putback unevictable pages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 13/84] ALSA: hda - Use ALC880_FIXUP_FUJITSU for FSC Amilo M1437 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 27/84] parisc: Use double word condition in 64bit CAS operation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 64/84] usbnet: Get EVENT_NO_RUNTIME_PM bit before it is cleared Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 35/84] IB/qib: Change lkey table allocation to support more MRs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 71/84] packet: missing dev_put() in packet_do_bind() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 61/84] netlink: dont hold mutex in rcu callback when releasing mmapd ring Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 57/84] ipv6: lock socket in ip6_datagram_connect() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 37/84] IB/uverbs: Fix race between ib_uverbs_open and remove_one Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 65/84] ipv6: fix exthdrs offload registration in out_rt path Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 53/84] net: Fix skb csum races when peeking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 48/84] bridge: mdb: zero out the local br_ip variable before use Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 43/84] ipv6: Make MLD packets to only be processed locally Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:30 +0200
[PATCH 3.14 44/84] net: graceful exit from netif_alloc_netdev_queues() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 56/84] isdn/gigaset: reset tty->receive_room when attaching ser_gigaset Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 49/84] net: pktgen: fix race between pktgen_thread_worker() and kthread_stop() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 33/84] xen/gntdev: convert priv->lock to a mutex Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 51/84] net: call rcu_read_lock early in process_backlog Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 36/84] IB/uverbs: reject invalid or unknown opcodes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 32/84] md/raid10: always set reshape_safe when initializing reshape_position. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 34/84] hfs: fix B-tree corruption after insertion at position 0 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 50/84] net: do not process device backlog during unregistration Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 54/84] net: Fix skb_set_peeked use-after-free bug Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 68/84] sctp: fix race on protocol/netns initialization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 45/84] rtnetlink: verify IFLA_VF_INFO attributes before passing them to driver Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 30/84] fs: if a coredump already exists, unlink and recreate with O_EXCL Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 77/84] x86/nmi: Enable nested do_nmi() handling for 64-bit kernels Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 74/84] bna: fix interrupts storm caused by erroneous packets Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 41/84] stmmac: troubleshoot unexpected bits in des0 & des1 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 31/84] mmc: core: fix race condition in mmc_wait_data_done Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 66/84] net/ipv6: Correct PIM6 mrt_lock handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 42/84] hfs,hfsplus: cache pages correctly between bnode_create and bnode_free Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:40 +0200
[PATCH 3.14 17/84] CIFS: fix type confusion in copy offload ioctl Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 20/84] x86/mm: Initialize pmd_idx in page_table_range_init_count() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 40/84] stmmac: fix check for phydev being open Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
Re: [PATCH 3.14 40/84] stmmac: fix check for phydev being open Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2015-09-30 13:30 +0200
Re: [PATCH 3.14 40/84] stmmac: fix check for phydev being open Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-10-01 05:10 +0200
[PATCH 3.14 22/84] [media] v4l: omap3isp: Fix sub-device power management code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 11/84] Input: evdev - do not report errors form flush() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 16/84] powerpc/mm: Recompute hash value after a failed update Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 24/84] NFSv4: dont set SETATTR for O_RDONLY|O_EXCL Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 15/84] powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 09/84] arm64: errata: add module build workaround for erratum #843419 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 10/84] arm64: KVM: Disable virtual timer even if the guest is not using it Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 23/84] Btrfs: check if previous transaction aborted to avoid fs corruption Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 05/84] mac80211: enable assoc check for mesh interfaces Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 28/84] parisc: Filter out spurious interrupts in PA-RISC irq handler Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 39/84] IB/mlx4: Use correct SL on AH query under RoCE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 19/84] mm: check if section present during memory block registering Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 25/84] NFS: Fix a NULL pointer dereference of migration recovery ops for v4.2 client Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 04/84] tg3: Fix temperature reporting Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 18/84] Add radeon suspend/resume quirk for HP Compaq dc5750. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
[PATCH 3.14 26/84] NFS: nfs_set_pgio_error sometimes misses errors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 17:50 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2015-09-29 19:00 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-29 21:50 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Guenter Roeck <linux@roeck-us.net> - 2015-09-29 23:20 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-30 04:20 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-30 08:00 +0200
Re: [PATCH 3.14 00/84] 3.14.54-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2015-09-30 08:10 +0200
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