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  1. 27 Oct, 2015 6 commits
  3. 26 Oct, 2015 1 commit
  5. 22 Oct, 2015 1 commit
  7. 09 Oct, 2015 1 commit
  9. 07 Oct, 2015 12 commits
    • Martin Schwidefsky's avatar
      s390/3270: redraw screen on unsolicited device end · 8638bf1f
      Martin Schwidefsky authored 
      commit 05bfd70b upstream.

If a 3270 terminal is disconnected and later reconnected again,
it gets an unsolicited device end. This is currently ignored and
you have to hit the clear key to get the screen redrawn.
Add an automatic full redraw of the screen for this case.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      8638bf1f
    • Joerg Roedel's avatar
      iommu/amd: Handle integer overflow in dma_ops_area_alloc · 3720583b
      Joerg Roedel authored 
      commit e6aabee0 upstream.

Handle this case to make sure boundary_size does not become
0 and trigger a BUG_ON later.
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      3720583b
    • Noel Power's avatar
      client MUST ignore EncryptionKeyLength if CAP_EXTENDED_SECURITY is set · 6428ec07
      Noel Power authored 
      commit f291095f upstream.

[MS-SMB] 2.2.4.5.2.1 states:

"ChallengeLength (1 byte): When the CAP_EXTENDED_SECURITY bit is set,
 the server MUST set this value to zero and clients MUST ignore this
 value."
Signed-off-by: default avatarNoel Power <noel.power@suse.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      6428ec07
    • Teunis van Beelen's avatar
      USB: usbtmc: add device quirk for Rigol DS6104 · 3640b336
      Teunis van Beelen authored 
      commit f5042022 upstream.

Recently we purchased the Rigol DS6104 and when I try to operate it from
my Linux pc, everything works well with the default usbtmc driver,
except when I want to download a big datachunk like a screenshot. This
bitmapfile has a size of 1152054 bytes but I receive a smaller file and
no new packets can be read.

When I took a look at the driver source, I found this "Rigol quirk" and
I added the id of the new DS series oscilloscopes to this list. I
compiled it and loaded the new driver and now everything seems to work
fine.
Signed-off-by: default avatarTeunis van Beelen <teuniz@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      3640b336
    • Robert Schlabbach's avatar
      usb: core: Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset · f6d11e6e
      Robert Schlabbach authored 
      commit fb6d1f7d upstream.

Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset.

Dissolve the function hub_port_finish_reset() completely and divide the
actions to be taken into those which need to be done after each reset
attempt and those which need to be done after the full procedure is
complete, and place them in the appropriate places in hub_port_reset().
Also, remove an unneeded forward declaration of hub_port_reset().

Verbose Problem Description:

USB 3.0 devices may be "lost for good" during a hub port reset.
This makes Linux unable to boot from USB 3.0 devices in certain
constellations of host controllers and devices, because the USB device is
lost during initialization, preventing the rootfs from being mounted.

The underlying problem is that in the affected constellations, during the
processing inside hub_port_reset(), the hub link state goes from 0 to
SS.inactive after the initial reset, and back to 0 again only after the
following "warm" reset.

However, hub_port_finish_reset() is called after each reset attempt and
sets the state the connected USB device based on the "preliminary" status
of the hot reset to USB_STATE_NOTATTACHED due to SS.inactive, yet when
the following warm reset is complete and hub_port_finish_reset() is
called again, its call to set the device to USB_STATE_DEFAULT is blocked
by usb_set_device_state() which does not allow taking USB devices out of
USB_STATE_NOTATTACHED state.

Thanks to Alan Stern for guiding me to the proper solution and how to
submit it.

Link: http://lkml.kernel.org/r/trinity-25981484-72a9-4d46-bf17-9c1cf9301a31-1432073240136%20()%203capp-gmx-bs27Signed-off-by: default avatarRobert Schlabbach <robert_s@gmx.net>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarOliver Neukum <oneukum@suse.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      f6d11e6e
    • Mathias Nyman's avatar
      xhci: rework cycle bit checking for new dequeue pointers · 982fe712
      Mathias Nyman authored 
      commit 365038d8 upstream.

When we manually need to move the TR dequeue pointer we need to set the
correct cycle bit as well. Previously we used the trb pointer from the
last event received as a base, but this was changed in
commit 1f81b6d2 ("usb: xhci: Prefer endpoint context dequeue pointer")
to use the dequeue pointer from the endpoint context instead

It turns out some Asmedia controllers advance the dequeue pointer
stored in the endpoint context past the event triggering TRB, and
this messed up the way the cycle bit was calculated.

Instead of adding a quirk or complicating the already hard to follow cycle bit
code, the whole cycle bit calculation is now simplified and adapted to handle
event and endpoint context dequeue pointer differences.

[js] do not touch find_trb_seg, it is still in use in other portions
     of the code

Fixes: 1f81b6d2 ("usb: xhci: Prefer endpoint context dequeue pointer")
Reported-by: default avatarMaciej Puzio <mx34567@gmail.com>
Reported-by: default avatarEvan Langlois <uudruid74@gmail.com>
Reviewed-by: default avatarJulius Werner <jwerner@chromium.org>
Tested-by: default avatarMaciej Puzio <mx34567@gmail.com>
Tested-by: default avatarEvan Langlois <uudruid74@gmail.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      982fe712
    • Mathias Nyman's avatar
      xhci: Workaround for PME stuck issues in Intel xhci · 19c8c601
      Mathias Nyman authored 
      commit b8cb91e0 upstream.

The xhci in Intel Sunrisepoint and Cherryview platforms need a driver
workaround for a Stuck PME that might either block PME events in suspend,
or create spurious PME events preventing runtime suspend.

Workaround is to clear a internal PME flag, BIT(28) in a vendor specific
PMCTRL register at offset 0x80a4, in both suspend resume callbacks

Without this, xhci connected usb devices might never be able to wake up the
system from suspend, or prevent device from going to suspend (xhci d3)
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      19c8c601
    • Jan H. Schönherr's avatar
      sched: Fix cpu_active_mask/cpu_online_mask race · ff7987cd
      Jan H. Schönherr authored 
      commit dd9d3843 upstream.

There is a race condition in SMP bootup code, which may result
in

    WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
    workqueue_cpu_up_callback()
or
    kernel BUG at kernel/smpboot.c:135!

It can be triggered with a bit of luck in Linux guests running
on busy hosts.

	CPU0                        CPUn
	====                        ====

	_cpu_up()
	  __cpu_up()
				    start_secondary()
				      set_cpu_online()
					cpumask_set_cpu(cpu,
						   to_cpumask(cpu_online_bits));
	  cpu_notify(CPU_ONLINE)
	    <do stuff, see below>
					cpumask_set_cpu(cpu,
						   to_cpumask(cpu_active_bits));

During the various CPU_ONLINE callbacks CPUn is online but not
active. Several things can go wrong at that point, depending on
the scheduling of tasks on CPU0.

Variant 1:

  cpu_notify(CPU_ONLINE)
    workqueue_cpu_up_callback()
      rebind_workers()
        set_cpus_allowed_ptr()

  This call fails because it requires an active CPU; rebind_workers()
  ends with a warning:

    WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
    workqueue_cpu_up_callback()

Variant 2:

  cpu_notify(CPU_ONLINE)
    smpboot_thread_call()
      smpboot_unpark_threads()
       ..
        __kthread_unpark()
          __kthread_bind()
          wake_up_state()
           ..
            select_task_rq()
              select_fallback_rq()

  The ->wake_cpu of the unparked thread is not allowed, making a call
  to select_fallback_rq() necessary. Then, select_fallback_rq() cannot
  find an allowed, active CPU and promptly resets the allowed CPUs, so
  that the task in question ends up on CPU0.

  When those unparked tasks are eventually executed, they run
  immediately into a BUG:

    kernel BUG at kernel/smpboot.c:135!

Just changing the order in which the online/active bits are set
(and adding some memory barriers), would solve the two issues
above. However, it would change the order of operations back to
the one before commit 6acbfb96 ("sched: Fix hotplug vs.
set_cpus_allowed_ptr()"), thus, reintroducing that particular
problem.

Going further back into history, we have at least the following
commits touching this topic:
- commit 2baab4e9 ("sched: Fix select_fallback_rq() vs cpu_active/cpu_online")
- commit 5fbd036b ("sched: Cleanup cpu_active madness")

Together, these give us the following non-working solutions:

  - secondary CPU sets active before online, because active is assumed to
    be a subset of online;

  - secondary CPU sets online before active, because the primary CPU
    assumes that an online CPU is also active;

  - secondary CPU sets online and waits for primary CPU to set active,
    because it might deadlock.

Commit 875ebe94 ("powerpc/smp: Wait until secondaries are
active & online") introduces an arch-specific solution to this
arch-independent problem.

Now, go for a more general solution without explicit waiting and
simply set active twice: once on the secondary CPU after online
was set and once on the primary CPU after online was seen.

set_cpus_allowed_ptr()")
Signed-off-by: default avatarJan H. Schönherr <jschoenh@amazon.de>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Anton Blanchard <anton@samba.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Wilson <msw@amazon.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6acbfb96 ("sched: Fix hotplug vs. set_cpus_allowed_ptr()")
Link: http://lkml.kernel.org/r/1439408156-18840-1-git-send-email-jschoenh@amazon.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      ff7987cd
    • Paul E. McKenney's avatar
      rcu: Reject memory-order-induced stall-warning false positives · 4438bb21
      Paul E. McKenney authored 
      commit 26cdfedf upstream.

If a system is idle from an RCU perspective for longer than specified
by CONFIG_RCU_CPU_STALL_TIMEOUT, and if one CPU starts a grace period
just as a second checks for CPU stalls, and if this second CPU happens
to see the old value of rsp->jiffies_stall, it will incorrectly report a
CPU stall.  This is quite rare, but apparently occurs deterministically
on systems with about 6TB of memory.

This commit therefore orders accesses to the data used to determine
whether or not a CPU stall is in progress.  Grace-period initialization
and cleanup first increments rsp->completed to mark the end of the
previous grace period, then records the current jiffies in rsp->gp_start,
then records the jiffies at which a stall can be expected to occur in
rsp->jiffies_stall, and finally increments rsp->gpnum to mark the start
of the new grace period.  Now, this ordering by itself does not prevent
false positives.  For example, if grace-period initialization was delayed
between recording rsp->gp_start and rsp->jiffies_stall, the CPU stall
warning code might still see an old value of rsp->jiffies_stall.

Therefore, this commit also orders the CPU stall warning accesses as
well, loading rsp->gpnum and jiffies, then rsp->jiffies_stall, then
rsp->gp_start, and finally rsp->completed.  This ordering means that
the false-positive scenario in the previous paragraph would result
in rsp->completed being greater than or equal to rsp->gpnum, which is
never valid for a CPU stall, allowing the false positive to be rejected.
Furthermore, any fetch that gets an old value of rsp->jiffies_stall
must also get an old value of rsp->gpnum, which will again be rejected
by the comparison of rsp->gpnum and rsp->completed.  Situations where
rsp->gp_start is later than rsp->jiffies_stall are also rejected, as
are situations where jiffies is less than rsp->jiffies_stall.

Although use of unsynchronized accesses means that there are likely
still some false-positive scenarios (synchronization has proven to be
a very bad idea on large systems), this should get rid of a large class
of these scenarios.
Reported-by: default avatarFabian Herschel <fabian.herschel@suse.com>
Reported-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarMichal Hocko <mhocko@suse.cz>
Tested-by: default avatarJochen Striepe <jochen@tolot.escape.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      4438bb21
    • Jan Kara's avatar
      jbd2: avoid infinite loop when destroying aborted journal · cd9683b6
      Jan Kara authored 
      commit 841df7df upstream.

Commit 6f6a6fda "jbd2: fix ocfs2 corrupt when updating journal
superblock fails" changed jbd2_cleanup_journal_tail() to return EIO
when the journal is aborted. That makes logic in
jbd2_log_do_checkpoint() bail out which is fine, except that
jbd2_journal_destroy() expects jbd2_log_do_checkpoint() to always make
a progress in cleaning the journal. Without it jbd2_journal_destroy()
just loops in an infinite loop.

Fix jbd2_journal_destroy() to cleanup journal checkpoint lists of
jbd2_log_do_checkpoint() fails with error.
Reported-by: default avatarEryu Guan <guaneryu@gmail.com>
Tested-by: default avatarEryu Guan <guaneryu@gmail.com>
Fixes: 6f6a6fdaSigned-off-by: default avatarJan Kara <jack@suse.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      cd9683b6
    • Andy Lutomirski's avatar
      x86/paravirt: Replace the paravirt nop with a bona fide empty function · ad158ee3
      Andy Lutomirski authored 
      commit fc57a7c6 upstream.

PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an
example, trimmed for readability):

    ff 15 00 00 00 00       callq  *0x0(%rip)        # 2796 <nmi+0x6>
              2792: R_X86_64_PC32     pv_irq_ops+0x2c

That's a call through a function pointer to regular C function that
does nothing on native boots, but that function isn't protected
against kprobes, isn't marked notrace, and is certainly not
guaranteed to preserve any registers if the compiler is feeling
perverse.  This is bad news for a CLBR_NONE operation.

Of course, if everything works correctly, once paravirt ops are
patched, it gets nopped out, but what if we hit this code before
paravirt ops are patched in?  This can potentially cause breakage
that is very difficult to debug.

A more subtle failure is possible here, too: if _paravirt_nop uses
the stack at all (even just to push RBP), it will overwrite the "NMI
executing" variable if it's called in the NMI prologue.

The Xen case, perhaps surprisingly, is fine, because it's already
written in asm.

Fix all of the cases that default to paravirt_nop (including
adjust_exception_frame) with a big hammer: replace paravirt_nop with
an asm function that is just a ret instruction.

The Xen case may have other problems, so document them.

This is part of a fix for some random crashes that Sasha saw.
Reported-and-tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      ad158ee3
    • Andy Lutomirski's avatar
      x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code · a6f39d84
      Andy Lutomirski authored 
      commit 83c133cf upstream.

The NMI entry code that switches to the normal kernel stack needs to
be very careful not to clobber any extra stack slots on the NMI
stack.  The code is fine under the assumption that SWAPGS is just a
normal instruction, but that assumption isn't really true.  Use
SWAPGS_UNSAFE_STACK instead.

This is part of a fix for some random crashes that Sasha saw.

Fixes: 9b6e6a83 ("x86/nmi/64: Switch stacks on userspace NMI entry")
Reported-and-tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/974bc40edffdb5c2950a5c4977f821a446b76178.1442791737.git.luto@kernel.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      a6f39d84
  11. 05 Oct, 2015 9 commits
    • Jiri Slaby's avatar
      Linux 3.12.49 · c0007620
      Jiri Slaby authored
      c0007620
    • Paul Mackerras's avatar
      powerpc/MSI: Fix race condition in tearing down MSI interrupts · d5c47ccb
      Paul Mackerras authored 
      commit e297c939 upstream.

This fixes a race which can result in the same virtual IRQ number
being assigned to two different MSI interrupts.  The most visible
consequence of that is usually a warning and stack trace from the
sysfs code about an attempt to create a duplicate entry in sysfs.

The race happens when one CPU (say CPU 0) is disposing of an MSI
while another CPU (say CPU 1) is setting up an MSI.  CPU 0 calls
(for example) pnv_teardown_msi_irqs(), which calls
msi_bitmap_free_hwirqs() to indicate that the MSI (i.e. its
hardware IRQ number) is no longer in use.  Then, before CPU 0 gets
to calling irq_dispose_mapping() to free up the virtal IRQ number,
CPU 1 comes in and calls msi_bitmap_alloc_hwirqs() to allocate an
MSI, and gets the same hardware IRQ number that CPU 0 just freed.
CPU 1 then calls irq_create_mapping() to get a virtual IRQ number,
which sees that there is currently a mapping for that hardware IRQ
number and returns the corresponding virtual IRQ number (which is
the same virtual IRQ number that CPU 0 was using).  CPU 0 then
calls irq_dispose_mapping() and frees that virtual IRQ number.
Now, if another CPU comes along and calls irq_create_mapping(), it
is likely to get the virtual IRQ number that was just freed,
resulting in the same virtual IRQ number apparently being used for
two different hardware interrupts.

To fix this race, we just move the call to msi_bitmap_free_hwirqs()
to after the call to irq_dispose_mapping().  Since virq_to_hw()
doesn't work for the virtual IRQ number after irq_dispose_mapping()
has been called, we need to call it before irq_dispose_mapping() and
remember the result for the msi_bitmap_free_hwirqs() call.

The pattern of calling msi_bitmap_free_hwirqs() before
irq_dispose_mapping() appears in 5 places under arch/powerpc, and
appears to have originated in commit 05af7bd2 ("[POWERPC] MPIC
U3/U4 MSI backend") from 2007.

Fixes: 05af7bd2 ("[POWERPC] MPIC U3/U4 MSI backend")
Reported-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      d5c47ccb
    • Neil Brown's avatar
      md: flush ->event_work before stopping array. · e460fa8b
      Neil Brown authored 
      commit ee5d004f upstream.

The 'event_work' worker used by dm-raid may still be running
when the array is stopped.  This can result in an oops.

So flush the workqueue on which it is run after detaching
and before destroying the device.
Reported-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Fixes: 9d09e663 ("dm: raid456 basic support")
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      e460fa8b
    • Eric W. Biederman's avatar
      vfs: Test for and handle paths that are unreachable from their mnt_root · 2ca1ae46
      Eric W. Biederman authored 
      commit 397d425d upstream.

In rare cases a directory can be renamed out from under a bind mount.
In those cases without special handling it becomes possible to walk up
the directory tree to the root dentry of the filesystem and down
from the root dentry to every other file or directory on the filesystem.

Like division by zero .. from an unconnected path can not be given
a useful semantic as there is no predicting at which path component
the code will realize it is unconnected.  We certainly can not match
the current behavior as the current behavior is a security hole.

Therefore when encounting .. when following an unconnected path
return -ENOENT.

- Add a function path_connected to verify path->dentry is reachable
  from path->mnt.mnt_root.  AKA to validate that rename did not do
  something nasty to the bind mount.

  To avoid races path_connected must be called after following a path
  component to it's next path component.
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      2ca1ae46
    • Eric W. Biederman's avatar
      dcache: Handle escaped paths in prepend_path · b32388c0
      Eric W. Biederman authored 
      commit cde93be4 upstream.

A rename can result in a dentry that by walking up d_parent
will never reach it's mnt_root.  For lack of a better term
I call this an escaped path.

prepend_path is called by four different functions __d_path,
d_absolute_path, d_path, and getcwd.

__d_path only wants to see paths are connected to the root it passes
in.  So __d_path needs prepend_path to return an error.

d_absolute_path similarly wants to see paths that are connected to
some root.  Escaped paths are not connected to any mnt_root so
d_absolute_path needs prepend_path to return an error greater
than 1.  So escaped paths will be treated like paths on lazily
unmounted mounts.

getcwd needs to prepend "(unreachable)" so getcwd also needs
prepend_path to return an error.

d_path is the interesting hold out.  d_path just wants to print
something, and does not care about the weird cases.  Which raises
the question what should be printed?

Given that <escaped_path>/<anything> should result in -ENOENT I
believe it is desirable for escaped paths to be printed as empty
paths.  As there are not really any meaninful path components when
considered from the perspective of a mount tree.

So tweak prepend_path to return an empty path with an new error
code of 3 when it encounters an escaped path.
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      b32388c0
    • Andy Lutomirski's avatar
      x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detection · 864c198b
      Andy Lutomirski authored 
      commit 810bc075 upstream.

We have a tricky bug in the nested NMI code: if we see RSP
pointing to the NMI stack on NMI entry from kernel mode, we
assume that we are executing a nested NMI.

This isn't quite true.  A malicious userspace program can point
RSP at the NMI stack, issue SYSCALL, and arrange for an NMI to
happen while RSP is still pointing at the NMI stack.

Fix it with a sneaky trick.  Set DF in the region of code that
the RSP check is intended to detect.  IRET will clear DF
atomically.

( Note: other than paravirt, there's little need for all this
  complexity. We could check RIP instead of RSP. )
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarSteven 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: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      864c198b
    • Andy Lutomirski's avatar
      x86/nmi/64: Reorder nested NMI checks · 10c99c97
      Andy Lutomirski authored 
      commit a27507ca 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: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarSteven 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: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      10c99c97
    • Andy Lutomirski's avatar
      x86/nmi/64: Improve nested NMI comments · d2ad2032
      Andy Lutomirski authored 
      commit 0b22930e upstream.

I found the nested NMI documentation to be difficult to follow.
Improve the comments.
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarSteven 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: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      d2ad2032
    • Wilson Kok's avatar
      fib_rules: fix fib rule dumps across multiple skbs · 737ea802
      Wilson Kok authored 
      [ Upstream commit 41fc0143 ]

dump_rules returns skb length and not error.
But when family == AF_UNSPEC, the caller of dump_rules
assumes that it returns an error. Hence, when family == AF_UNSPEC,
we continue trying to dump on -EMSGSIZE errors resulting in
incorrect dump idx carried between skbs belonging to the same dump.
This results in fib rule dump always only dumping rules that fit
into the first skb.

This patch fixes dump_rules to return error so that we exit correctly
and idx is correctly maintained between skbs that are part of the
same dump.

[rd] fix for <= 3.19: fib_nl_fill_rule() returns skb->len, make the
     check 'err < 0'
Signed-off-by: default avatarWilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: default avatarRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      737ea802
  13. 30 Sep, 2015 10 commits
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