Right now, the kernel address filters in PT are prone to integer overflow
that may happen in adding filter's size to its offset to obtain the end
of the range. Such an overflow would also throw a #GP in the PT event
configuration path.

Fix this by explicitly validating the result of this calculation.
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org # v4.7
Cc: stable@vger.kernel.org#v4.7
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915151352.21306-4-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The kernel_ip() filter is used mostly by the DS/LBR code to look at the
branch addresses, but Intel PT also uses it to validate the address
filter offsets for kernel addresses, for which it is not sufficient:
supplying something in bits 64:48 that's not a sign extension of the lower
address bits (like 0xf00d000000000000) throws a #GP.

This patch adds address validation for the user supplied kernel filters.
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org # v4.7
Cc: stable@vger.kernel.org#v4.7
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915151352.21306-3-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

PT address filter configuration requires that a range is specified by
its first and last address, but at the moment we're obtaining the end
of the range by adding user specified size to its start, which is off
by one from what it actually needs to be.

Fix this and make sure that zero-sized filters don't pass the filter
validation.
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org # v4.7
Cc: stable@vger.kernel.org#v4.7
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915151352.21306-2-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

At the moment, intel_bts events get disabled from intel PMU's disable
callback, which includes event scheduling transactions of said PMU,
which have nothing to do with intel_bts events.

We do want to keep intel_bts events off inside the PMI handler to
avoid filling up their buffer too soon.

This patch moves intel_bts enabling/disabling directly to the PMI
handler.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915082233.11065-1-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Pull PCI fixes from Bjorn Helgaas:
 "Here are two changes for v4.8.  The first fixes a "[Firmware Bug]: reg
  0x10: invalid BAR (can't size)" warning on Haswell, and the second
  fixes a problem in some new runtime suspend functionality we merged
  for v4.8.  Summary:

  Enumeration:
    Mark Haswell Power Control Unit as having non-compliant BARs (Bjorn Helgaas)

  Power management:
    Fix bridge_d3 update on device removal (Lukas Wunner)"

* tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Fix bridge_d3 update on device removal
  PCI: Mark Haswell Power Control Unit as having non-compliant BARs

Pull uaccess fixes from Al Viro:
 "Fixes for broken uaccess primitives - mostly lack of proper zeroing
  in copy_from_user()/get_user()/__get_user(), but for several
  architectures there's more (broken clear_user() on frv and
  strncpy_from_user() on hexagon)"

* 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  avr32: fix copy_from_user()
  microblaze: fix __get_user()
  microblaze: fix copy_from_user()
  m32r: fix __get_user()
  blackfin: fix copy_from_user()
  sparc32: fix copy_from_user()
  sh: fix copy_from_user()
  sh64: failing __get_user() should zero
  score: fix copy_from_user() and friends
  score: fix __get_user/get_user
  s390: get_user() should zero on failure
  ppc32: fix copy_from_user()
  parisc: fix copy_from_user()
  openrisc: fix copy_from_user()
  nios2: fix __get_user()
  nios2: copy_from_user() should zero the tail of destination
  mn10300: copy_from_user() should zero on access_ok() failure...
  mn10300: failing __get_user() and get_user() should zero
  mips: copy_from_user() must zero the destination on access_ok() failure
  ARC: uaccess: get_user to zero out dest in cause of fault
  ...

Pull xen regression fix from David Vrabel:
 "Fix SMP boot in arm guests"

* tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  arm/xen: fix SMP guests boot

Commit 88e957d6 ("xen: introduce xen_vcpu_id mapping") broke SMP
ARM guests on Xen. When FIFO-based event channels are in use (this is
the default), evtchn_fifo_alloc_control_block() is called on
CPU_UP_PREPARE event and this happens before we set up xen_vcpu_id
mapping in xen_starting_cpu. Temporary fix the issue by setting direct
Linux CPU id <-> Xen vCPU id mapping for all possible CPUs at boot. We
don't currently support kexec/kdump on Xen/ARM so these ids always
match.

In future, we have several ways to solve the issue, e.g.:

- Eliminate all hypercalls from CPU_UP_PREPARE, do them from the
  starting CPU. This can probably be done for both x86 and ARM and, if
  done, will allow us to get Xen's idea of vCPU id from CPUID/MPIDR on
  the starting CPU directly, no messing with ACPI/device tree
  required.

- Save vCPU id information from ACPI/device tree on ARM and use it to
  initialize xen_vcpu_id mapping. This is the same trick we currently
  do on x86.
Reported-by: Julien Grall <julien.grall@arm.com>
Tested-by: Wei Chen <Wei.Chen@arm.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

really ugly, but apparently avr32 compilers turns access_ok() into
something so bad that they want it in assembler.  Left that way,
zeroing added in inline wrapper.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* should zero on any failure
* __get_user() should use __copy_from_user(), not copy_from_user()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

should clear on access_ok() failures.  Also remove the useless
range truncation logics.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... that should zero on faults.  Also remove the <censored> helpful
logics wrt range truncation copied from ppc32.  Where it had ever
been needed only in case of copy_from_user() *and* had not been merged
into the mainline until a month after the need had disappeared.
A decade before openrisc went into mainline, I might add...

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

a) should not leave crap on fault
b) should _not_ require access_ok() in any cases.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Al reported potential issue with ARC get_user() as it wasn't clearing
out destination pointer in case of fault due to bad address etc.

Verified using following

| {
|  	u32 bogus1 = 0xdeadbeef;
|	u64 bogus2 = 0xdead;
|	int rc1, rc2;
|
|  	pr_info("Orig values %x %llx\n", bogus1, bogus2);
|	rc1 = get_user(bogus1, (u32 __user *)0x40000000);
|	rc2 = get_user(bogus2, (u64 __user *)0x50000000);
|	pr_info("access %d %d, new values %x %llx\n",
|		rc1, rc2, bogus1, bogus2);
| }

| [ARCLinux]# insmod /mnt/kernel-module/qtn.ko
| Orig values deadbeef dead
| access -14 -14, new values 0 0
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).

Cc: stable@vger.kernel.org
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It should check access_ok().  Otherwise a bunch of places turn into
trivially exploitable rootholes.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* copy_from_user() on access_ok() failure ought to zero the destination
* none of those primitives should skip the access_ok() check in case of
small constant size.

Cc: stable@vger.kernel.org
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

both for access_ok() failures and for faults halfway through

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Starting with v4.8, we allow a PCIe port to runtime suspend to D3hot if the
port itself and its children satisfy a number of conditions.  Once a child
is removed, we recheck those conditions in case the removed device was
blocking the port from suspending.

The rechecking needs to happen *after* the device has been removed from the
bus it resides on.  Otherwise when walking the port's subordinate bus in
pci_bridge_d3_update(), the device being removed would erroneously still be
taken into account.

However the device is removed from the bus_list in pci_destroy_dev() and we
currently recheck *before* that.  Fix it.

Fixes: 9d26d3a8 ("PCI: Put PCIe ports into D3 during suspend")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <mika.westerberg@linux.intel.com>

Pull x86 fixes from Ingo Molnar:
 "Three fixes:

   - AMD microcode loading fix with randomization

   - an lguest tooling fix

   - and an APIC enumeration boundary condition fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Fix num_processors value in case of failure
  tools/lguest: Don't bork the terminal in case of wrong args
  x86/microcode/AMD: Fix load of builtin microcode with randomized memory

Pull scheduler fix from Ingo Molnar:
 "A try_to_wake_up() memory ordering race fix causing a busy-loop in
  ttwu()"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Fix a race between try_to_wake_up() and a woken up task

Pull perf fixes from Ingo Molnar:
 "This contains:

   - a set of fixes found by directed-random perf fuzzing efforts by
     Vince Weaver, Alexander Shishkin and Peter Zijlstra

   - a cqm driver crash fix

   - an AMD uncore driver use after free fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix PEBSv3 record drain
  perf/x86/intel/bts: Kill a silly warning
  perf/x86/intel/bts: Fix BTS PMI detection
  perf/x86/intel/bts: Fix confused ordering of PMU callbacks
  perf/core: Fix aux_mmap_count vs aux_refcount order
  perf/core: Fix a race between mmap_close() and set_output() of AUX events
  perf/x86/amd/uncore: Prevent use after free
  perf/x86/intel/cqm: Check cqm/mbm enabled state in event init
  perf/core: Remove WARN from perf_event_read()

Pull locking fix from Ingo Molnar:
 "Another lockless_dereference() Sparse fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/barriers: Don't use sizeof(void) in lockless_dereference()

Pull EFI fixes from Ingo Molnar:
 "This contains a Xen fix, an arm64 fix and a race condition /
  robustization set of fixes related to ExitBootServices() usage and
  boundary conditions"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Use efi_exit_boot_services()
  efi/libstub: Use efi_exit_boot_services() in FDT
  efi/libstub: Introduce ExitBootServices helper
  efi/libstub: Allocate headspace in efi_get_memory_map()
  efi: Fix handling error value in fdt_find_uefi_params
  efi: Make for_each_efi_memory_desc_in_map() cope with running on Xen