1. 09 Nov, 2016 4 commits
    • James Hogan's avatar
      KVM: MIPS: Precalculate MMIO load resume PC · ff686d55
      James Hogan authored
      commit e1e575f6 upstream.
      
      The advancing of the PC when completing an MMIO load is done before
      re-entering the guest, i.e. before restoring the guest ASID. However if
      the load is in a branch delay slot it may need to access guest code to
      read the prior branch instruction. This isn't safe in TLB mapped code at
      the moment, nor in the future when we'll access unmapped guest segments
      using direct user accessors too, as it could read the branch from host
      user memory instead.
      
      Therefore calculate the resume PC in advance while we're still in the
      right context and save it in the new vcpu->arch.io_pc (replacing the no
      longer needed vcpu->arch.pending_load_cause), and restore it on MMIO
      completion.
      
      Fixes: e685c689 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: "Radim Krčmář <rkrcmar@redhat.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: linux-mips@linux-mips.org
      Cc: kvm@vger.kernel.org
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      [james.hogan@imgtec.com: Backport to 3.10..3.16]
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      ff686d55
    • Nicholas Mc Guire's avatar
      MIPS: KVM: Fix unused variable build warning · fb357699
      Nicholas Mc Guire authored
      commit 5f508c43 upstream.
      
      As kvm_mips_complete_mmio_load() did not yet modify PC at this point
      as James Hogans <james.hogan@imgtec.com> explained the curr_pc variable
      and the comments along with it can be dropped.
      Signed-off-by: default avatarNicholas Mc Guire <hofrat@osadl.org>
      Link: http://lkml.org/lkml/2015/5/8/422
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: kvm@vger.kernel.org
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/9993/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      [james.hogan@imgtec.com: Backport to 3.10..3.16]
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      fb357699
    • James Hogan's avatar
      KVM: MIPS: Drop other CPU ASIDs on guest MMU changes · e01f1c70
      James Hogan authored
      commit 91e4f1b6 upstream.
      
      When a guest TLB entry is replaced by TLBWI or TLBWR, we only invalidate
      TLB entries on the local CPU. This doesn't work correctly on an SMP host
      when the guest is migrated to a different physical CPU, as it could pick
      up stale TLB mappings from the last time the vCPU ran on that physical
      CPU.
      
      Therefore invalidate both user and kernel host ASIDs on other CPUs,
      which will cause new ASIDs to be generated when it next runs on those
      CPUs.
      
      We're careful only to do this if the TLB entry was already valid, and
      only for the kernel ASID where the virtual address it mapped is outside
      of the guest user address range.
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: "Radim Krčmář" <rkrcmar@redhat.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: linux-mips@linux-mips.org
      Cc: kvm@vger.kernel.org
      [james.hogan@imgtec.com: Backport to 3.10..3.16]
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      e01f1c70
    • Jiri Slaby's avatar
      Revert "KVM: MIPS: Drop other CPU ASIDs on guest MMU changes" · f668f2ee
      Jiri Slaby authored
      This reverts commit 168e5ebb, which is
      upstream commit 91e4f1b6. It caused
      build failures as it was improperly backported. New version is
      approaching, so revert this bad one.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Cc: James Hogan <james.hogan@imgtec.com>
      f668f2ee
  2. 08 Nov, 2016 32 commits
  3. 28 Oct, 2016 4 commits
    • Paul E. McKenney's avatar
      compiler: Allow 1- and 2-byte smp_load_acquire() and smp_store_release() · afe98b3b
      Paul E. McKenney authored
      commit 536fa402 upstream.
      
      CPUs without single-byte and double-byte loads and stores place some
      "interesting" requirements on concurrent code.  For example (adapted
      from Peter Hurley's test code), suppose we have the following structure:
      
      	struct foo {
      		spinlock_t lock1;
      		spinlock_t lock2;
      		char a; /* Protected by lock1. */
      		char b; /* Protected by lock2. */
      	};
      	struct foo *foop;
      
      Of course, it is common (and good) practice to place data protected
      by different locks in separate cache lines.  However, if the locks are
      rarely acquired (for example, only in rare error cases), and there are
      a great many instances of the data structure, then memory footprint can
      trump false-sharing concerns, so that it can be better to place them in
      the same cache cache line as above.
      
      But if the CPU does not support single-byte loads and stores, a store
      to foop->a will do a non-atomic read-modify-write operation on foop->b,
      which will come as a nasty surprise to someone holding foop->lock2.  So we
      now require CPUs to support single-byte and double-byte loads and stores.
      Therefore, this commit adjusts the definition of __native_word() to allow
      these sizes to be used by smp_load_acquire() and smp_store_release().
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      afe98b3b
    • Guenter Roeck's avatar
      metag: Only define atomic_dec_if_positive conditionally · e4dfd365
      Guenter Roeck authored
      commit 35d04077 upstream.
      
      The definition of atomic_dec_if_positive() assumes that
      atomic_sub_if_positive() exists, which is only the case if
      metag specific atomics are used. This results in the following
      build error when trying to build metag1_defconfig.
      
      kernel/ucount.c: In function 'dec_ucount':
      kernel/ucount.c:211: error:
      	implicit declaration of function 'atomic_sub_if_positive'
      
      Moving the definition of atomic_dec_if_positive() into the metag
      conditional code fixes the problem.
      
      Fixes: 6006c0d8 ("metag: Atomics, locks and bitops")
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      e4dfd365
    • Ming Lei's avatar
      scsi: Fix use-after-free · 04b46ca8
      Ming Lei authored
      commit bcd8f2e9 upstream.
      
      This patch fixes one use-after-free report[1] by KASAN.
      
      In __scsi_scan_target(), when a type 31 device is probed,
      SCSI_SCAN_TARGET_PRESENT is returned and the target will be scanned
      again.
      
      Inside the following scsi_report_lun_scan(), one new scsi_device
      instance is allocated, and scsi_probe_and_add_lun() is called again to
      probe the target and still see type 31 device, finally
      __scsi_remove_device() is called to remove & free the device at the end
      of scsi_probe_and_add_lun(), so cause use-after-free in
      scsi_report_lun_scan().
      
      And the following SCSI log can be observed:
      
      	scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
      	scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
      	scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
      	scsi 0:0:2:0: scsi scan: Sending REPORT LUNS to (try 0)
      	scsi 0:0:2:0: scsi scan: REPORT LUNS successful (try 0) result 0x0
      	scsi 0:0:2:0: scsi scan: REPORT LUN scan
      	scsi 0:0:2:0: scsi scan: INQUIRY pass 1 length 36
      	scsi 0:0:2:0: scsi scan: INQUIRY successful with code 0x0
      	scsi 0:0:2:0: scsi scan: peripheral device type of 31, no device added
      	BUG: KASAN: use-after-free in __scsi_scan_target+0xbf8/0xe40 at addr ffff88007b44a104
      
      This patch fixes the issue by moving the putting reference at
      the end of scsi_report_lun_scan().
      
      [1] KASAN report
      ==================================================================
      [    3.274597] PM: Adding info for serio:serio1
      [    3.275127] BUG: KASAN: use-after-free in __scsi_scan_target+0xd87/0xdf0 at addr ffff880254d8c304
      [    3.275653] Read of size 4 by task kworker/u10:0/27
      [    3.275903] CPU: 3 PID: 27 Comm: kworker/u10:0 Not tainted 4.8.0 #2121
      [    3.276258] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
      [    3.276797] Workqueue: events_unbound async_run_entry_fn
      [    3.277083]  ffff880254d8c380 ffff880259a37870 ffffffff94bbc6c1 ffff880078402d80
      [    3.277532]  ffff880254d8bb80 ffff880259a37898 ffffffff9459fec1 ffff880259a37930
      [    3.277989]  ffff880254d8bb80 ffff880078402d80 ffff880259a37920 ffffffff945a0165
      [    3.278436] Call Trace:
      [    3.278528]  [<ffffffff94bbc6c1>] dump_stack+0x65/0x84
      [    3.278797]  [<ffffffff9459fec1>] kasan_object_err+0x21/0x70
      [    3.279063] device: 'psaux': device_add
      [    3.279616]  [<ffffffff945a0165>] kasan_report_error+0x205/0x500
      [    3.279651] PM: Adding info for No Bus:psaux
      [    3.280202]  [<ffffffff944ecd22>] ? kfree_const+0x22/0x30
      [    3.280486]  [<ffffffff94bc2dc9>] ? kobject_release+0x119/0x370
      [    3.280805]  [<ffffffff945a0543>] __asan_report_load4_noabort+0x43/0x50
      [    3.281170]  [<ffffffff9507e1f7>] ? __scsi_scan_target+0xd87/0xdf0
      [    3.281506]  [<ffffffff9507e1f7>] __scsi_scan_target+0xd87/0xdf0
      [    3.281848]  [<ffffffff9507d470>] ? scsi_add_device+0x30/0x30
      [    3.282156]  [<ffffffff94f7f660>] ? pm_runtime_autosuspend_expiration+0x60/0x60
      [    3.282570]  [<ffffffff956ddb07>] ? _raw_spin_lock+0x17/0x40
      [    3.282880]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
      [    3.283200]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
      [    3.283563]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
      [    3.283882]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
      [    3.284173]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
      [    3.284492]  [<ffffffff941a8954>] ? pwq_dec_nr_in_flight+0x124/0x2a0
      [    3.284876]  [<ffffffff941d1770>] ? preempt_count_add+0x130/0x160
      [    3.285207]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
      [    3.285526]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
      [    3.285844]  [<ffffffff941aa810>] ? process_one_work+0x12d0/0x12d0
      [    3.286182]  [<ffffffff941bb365>] kthread+0x1c5/0x260
      [    3.286443]  [<ffffffff940855cd>] ? __switch_to+0x88d/0x1430
      [    3.286745]  [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
      [    3.287085]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
      [    3.287368]  [<ffffffff941bb1a0>] ? kthread_worker_fn+0x5a0/0x5a0
      [    3.287697] Object at ffff880254d8bb80, in cache kmalloc-2048 size: 2048
      [    3.288064] Allocated:
      [    3.288147] PID = 27
      [    3.288218]  [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
      [    3.288531]  [<ffffffff9459f246>] save_stack+0x46/0xd0
      [    3.288806]  [<ffffffff9459f4bd>] kasan_kmalloc+0xad/0xe0
      [    3.289098]  [<ffffffff9459c07e>] __kmalloc+0x13e/0x250
      [    3.289378]  [<ffffffff95078e5a>] scsi_alloc_sdev+0xea/0xcf0
      [    3.289701]  [<ffffffff9507de76>] __scsi_scan_target+0xa06/0xdf0
      [    3.290034]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
      [    3.290362]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
      [    3.290724]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
      [    3.291055]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
      [    3.291354]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
      [    3.291695]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
      [    3.292022]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
      [    3.292325]  [<ffffffff941bb365>] kthread+0x1c5/0x260
      [    3.292594]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
      [    3.292886] Freed:
      [    3.292945] PID = 27
      [    3.293016]  [<ffffffff940b27ab>] save_stack_trace+0x2b/0x50
      [    3.293327]  [<ffffffff9459f246>] save_stack+0x46/0xd0
      [    3.293600]  [<ffffffff9459fa61>] kasan_slab_free+0x71/0xb0
      [    3.293916]  [<ffffffff9459bac2>] kfree+0xa2/0x1f0
      [    3.294168]  [<ffffffff9508158a>] scsi_device_dev_release_usercontext+0x50a/0x730
      [    3.294598]  [<ffffffff941ace9a>] execute_in_process_context+0xda/0x130
      [    3.294974]  [<ffffffff9508107c>] scsi_device_dev_release+0x1c/0x20
      [    3.295322]  [<ffffffff94f566f6>] device_release+0x76/0x1e0
      [    3.295626]  [<ffffffff94bc2db7>] kobject_release+0x107/0x370
      [    3.295942]  [<ffffffff94bc29ce>] kobject_put+0x4e/0xa0
      [    3.296222]  [<ffffffff94f56e17>] put_device+0x17/0x20
      [    3.296497]  [<ffffffff9505201c>] scsi_device_put+0x7c/0xa0
      [    3.296801]  [<ffffffff9507e1bc>] __scsi_scan_target+0xd4c/0xdf0
      [    3.297132]  [<ffffffff9507e505>] scsi_scan_channel+0x105/0x160
      [    3.297458]  [<ffffffff9507e8a2>] scsi_scan_host_selected+0x212/0x2f0
      [    3.297829]  [<ffffffff9507eb3c>] do_scsi_scan_host+0x1bc/0x250
      [    3.298156]  [<ffffffff9507efc1>] do_scan_async+0x41/0x450
      [    3.298453]  [<ffffffff941c1fee>] async_run_entry_fn+0xfe/0x610
      [    3.298777]  [<ffffffff941a9a84>] process_one_work+0x544/0x12d0
      [    3.299105]  [<ffffffff941aa8e9>] worker_thread+0xd9/0x12f0
      [    3.299408]  [<ffffffff941bb365>] kthread+0x1c5/0x260
      [    3.299676]  [<ffffffff956dde9f>] ret_from_fork+0x1f/0x40
      [    3.299967] Memory state around the buggy address:
      [    3.300209]  ffff880254d8c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [    3.300608]  ffff880254d8c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [    3.300986] >ffff880254d8c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [    3.301408]                    ^
      [    3.301550]  ffff880254d8c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      [    3.301987]  ffff880254d8c400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      [    3.302396]
      ==================================================================
      
      Cc: Christoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      04b46ca8
    • Trond Myklebust's avatar
      NFSv4: Open state recovery must account for file permission changes · b160dbbd
      Trond Myklebust authored
      commit 304020fe upstream.
      
      If the file permissions change on the server, then we may not be able to
      recover open state. If so, we need to ensure that we mark the file
      descriptor appropriately.
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Tested-by: default avatarOleg Drokin <green@linuxhacker.ru>
      Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      b160dbbd