Return 0 if the operation was successful, not the userspace memory
value. Check that userspace value equals passed oldval, not itself.
Don't update *uval if the value wasn't read from userspace memory.

This fixes process hang due to infinite loop in futex_lock_pi.
It also fixes a bunch of glibc tests nptl/tst-mutexpi*.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Many uses of strncpy() on xtensa causes  a warning like

arch/xtensa/include/asm/string.h:56:42: warning: array subscript is above array bounds [-Warray-bounds]
   : "0" (__dest), "1" (__src), "r" (__src+__n)

This avoids the warning by turning the pointer arithmetic into an
integer operation that does not get checked the same way.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Output virtual addresses and sizes occupied by the main kernel sections:
.text, .rodata, .data, .init and .bss.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

This enables KASAN check of the destination buffer.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

memset on xtensa is capable of accessing user memory, but KASAN checks
if memset function is actually used for that and reports it as an error:

 ==================================================================
 BUG: KASAN: user-memory-access in padzero+0x4d/0x58
 Write of size 519 at addr 0049ddf9 by task init/1

 Call Trace:
  [<b0189978>] kasan_report+0x160/0x238
  [<b0188818>] check_memory_region+0xf8/0x100
  [<b018891c>] memset+0x20/0x34
  [<b0238b71>] padzero+0x4d/0x58
 ==================================================================

Use __memset in __xtensa_clear_user to avoid that.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Cover kernel addresses above 0x90000000 by the shadow map. Enable
HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills
shadow map with writable copies of kasan_zero_page. Call
kasan_early_init right after mmu initialization in the setup_arch.
Provide kasan_init that allocates proper shadow map pages from the
memblock and puts these pages into the shadow map for addresses from
VMALLOC area to the end of KSEG. Call kasan_init right after memblock
initialization. Don't use KASAN for the boot code, MMU and KASAN
initialization and page fault handler. Make kernel stack size 4 times
larger when KASAN is enabled to avoid stack overflows.
GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

The virtual address space between the page table and the VMALLOC region
is big enough to host KASAN shadow map and there's enough space between
the VMALLOC area and KSEG for the fixmap and kmap.
Move fixmap and kmap to the gap between VMALLOC area and KSEG, just
above the KSEG. Reorder entries in the kernel memory layout printing
code. Drop duplicate PGTABLE_START definition, use
XCHAL_PAGE_TABLE_VADDR instead.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

swapper_pg_dir is located in the .bss, so it's zero-initialized anyway.
With KASAN enabled paging_init will be called after KASAN
initialization, it must not erase page directory entries set up for
KASAN shadow map.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

KIO region placement may be specified in the device tree, that's why
it's initialized with the rest of MMU after the early_init_devtree. In
order to support KASAN the MMU must be initialized earlier.
Separate KIO initialization from the rest of MMU initialization.
Reinitialize KIO if its location is specified in the device tree.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Paging on xtensa architecture requires functioning exception handling
because hardware cannot transparently access page tables that are not
currently mapped by TLB. Exception handling is set up late in the
initialization process, but working paging is needed for KASAN.

Provide early_trap_init that sets up minimal exception handling
sufficient for KASAN to work.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Instead of using flat array of longs use normal C structure and generate
EXC_TABLE_* constants in the asm-offsets.c
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Replace #ifdef'fed/commented out debug printk statements with pr_debug.
Replace printk statements with pr_* equivalents.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

The implementation is adopted from the ARM arch. GCC 7.3, 8 or newer is
required for building the xtensa kernel with SSP.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Print hardware config ID on startup and config ID recorded in the
configuration if it doesn't match one read from the hardware.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Define kernel stack size in kmem_layout and use it in
current_thread_info, GET_THREAD_INFO, THREAD_SIZE and THERAD_SIZE_ORDER
definitions.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use ENTRY and ENDPROC throughout arch/xtensa/lib assembly sources.
Introduce asm/linkage.h and define xtensa-specific __ALIGN macro there.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Remove duplicate definitions of ALIGN/src_b/__src_b and SSA8/ssa8/__ssa8
from assembly sources and put single definition into asm/asmmacro.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Remove duplicate definitions of EX() and similar TRY/CATCH and SRC/DST
macros from assembly sources and put single definition into asm/asmmacro.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Now that xtensa assembly sources are compiled with -mlongcalls let the
assembler and linker relax call instructions into l32r + callx where
needed. This change makes the code cleaner and potentially a bit faster.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

vmlinux.lds.S doesn't do anything special with literals, so instead of
keeping them separate put them into the corresponding text sections.
Drop explicit .literal sections from the vmlinux.lds.S, use standard
section macros. Mark literal pool locations in the assembly sources.
Unfortunately assembler doesn't put literals into .init sections and
external libgcc may still have .literal sections, so sed transformation
to the linker script is still needed.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

By default xtensa gcc inserts memw for all volatile object accesses.
This is too pessimistic for the kernel: there should be no "normal"
volatile objects, and all special objects, like MMIO or objects shared
between CPUs should have explicit barriers.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Pull x86 fixes from Thomas Gleixner:
 "A set of small fixes:

   - make KGDB work again which got broken by the conversion of WARN()
     to #UD. The WARN fixup needs to run before the notifier callchain,
     otherwise KGDB tries to handle it and crashes.

   - disable KASAN in the ORC unwinder to prevent false positive KASAN
     warnings

   - prevent default mapping above 47bit when 5 level page tables are
     enabled

   - make the delay calibration optimization work correctly, which had
     the conditionals the wrong way around and was operating on data
     which was not yet updated.

   - remove the bogus X86_TRAP_BP trap init from the default IDT init
     table, which broke 32bit int3 handling by overwriting the correct
     int3 setup.

   - replace this_cpu* with boot_cpu_data access in the preemptible
     oprofile init code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/debug: Handle warnings before the notifier chain, to fix KGDB crash
  x86/mm: Fix ELF_ET_DYN_BASE for 5-level paging
  x86/idt: Remove X86_TRAP_BP initialization in idt_setup_traps()
  x86/oprofile/ppro: Do not use __this_cpu*() in preemptible context
  x86/unwind: Disable KASAN checking in the ORC unwinder
  x86/smpboot: Make optimization of delay calibration work correctly

Pull perf tool fixes from Thomas Gleixner:
 "A small set of fixes for perf tool:

   - synchronize the i915 drm header to avoid the 'out of date' warning

   - make sure that perf trace cleans up its temporary files on exit

   - unbreak the build with newer flex versions

   - add missing braces in the eBPF parsing rules"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tooling/headers: Sync the tools/include/uapi/drm/i915_drm.h UAPI header
  perf trace: Call machine__exit() at exit
  perf tools: Fix eBPF event specification parsing
  perf tools: Add "reject" option for parse-events.l

Pull networking fixes from David Miller:

 1) Use after free in vlan, from Cong Wang.

 2) Handle NAPI poll with a zero budget properly in mlx5 driver, from
    Saeed Mahameed.

 3) If DMA mapping fails in mlx5 driver, NULL out page, from Inbar
    Karmy.

 4) Handle overrun in RX FIFO of sun4i CAN driver, from Gerhard
    Bertelsmann.

 5) Missing return in mdb and vlan prepare phase of DSA layer, from
    Vivien Didelot.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  vlan: fix a use-after-free in vlan_device_event()
  net: dsa: return after vlan prepare phase
  net: dsa: return after mdb prepare phase
  can: ifi: Fix transmitter delay calculation
  tcp: fix tcp_fastretrans_alert warning
  tcp: gso: avoid refcount_t warning from tcp_gso_segment()
  can: peak: Add support for new PCIe/M2 CAN FD interfaces
  can: sun4i: handle overrun in RX FIFO
  can: c_can: don't indicate triple sampling support for D_CAN
  net/mlx5e: Increase Striding RQ minimum size limit to 4 multi-packet WQEs
  net/mlx5e: Set page to null in case dma mapping fails
  net/mlx5e: Fix napi poll with zero budget
  net/mlx5: Cancel health poll before sending panic teardown command
  net/mlx5: Loop over temp list to release delay events
  rds: ib: Fix NULL pointer dereference in debug code

Merge tag 'linux-can-fixes-for-4.14-20171110' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2017-11-10

this is a pull request for net/master.

The first patch by Richard Schütz for the c_can driver removes the false
indication to support triple sampling for d_can. Gerhard Bertelsmann's
patch for the sun4i driver improves the RX overrun handling. The patch
by Stephane Grosjean for the peak_canfd driver adds the PCI ids for
various new PCIe/M2 interfaces. Marek Vasut's patch for the ifi driver
fix transmitter delay calculation.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox, mlx5 fixes 2017-11-08

The following series includes some fixes for mlx5 core and etherent
driver.

Sorry for the late submission but as you can see i have some very
critical fixes below that i would like them merged into this RC.

Please pull and let me know if there is any problem.

For -stable:
('net/mlx5e: Set page to null in case dma mapping fails') kernels >= 4.13
('net/mlx5: FPGA, return -EINVAL if size is zero') kernels >= 4.13
('net/mlx5: Cancel health poll before sending panic teardown command') kernels >= 4.13

V1->V2:
	- Fix Reviewed-by tag of the 2nd patch.
	- Drop the FPGA 0 size fix, it needs some more change log info.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

After refcnt reaches zero, vlan_vid_del() could free
dev->vlan_info via RCU:

	RCU_INIT_POINTER(dev->vlan_info, NULL);
	call_rcu(&vlan_info->rcu, vlan_info_rcu_free);

However, the pointer 'grp' still points to that memory
since it is set before vlan_vid_del():

        vlan_info = rtnl_dereference(dev->vlan_info);
        if (!vlan_info)
                goto out;
        grp = &vlan_info->grp;

Depends on when that RCU callback is scheduled, we could
trigger a use-after-free in vlan_group_for_each_dev()
right following this vlan_vid_del().

Fix it by moving vlan_vid_del() before setting grp. This
is also symmetric to the vlan_vid_add() we call in
vlan_device_event().
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: efc73f4b ("net: Fix memory leak - vlan_info struct")
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Last minute upstream update to one of the UAPI headers - sync it with tooling,
to address this warning:

  Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h'

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf tooling fixes from Arnaldo Carvalho de Melo.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The current code does not return after successfully preparing the VLAN
addition on every ports member of a it. Fix this.

Fixes: 1ca4aa9c ("net: dsa: check VLAN capability of every switch")
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current code does not return after successfully preparing the MDB
addition on every ports member of a multicast group. Fix this.

Fixes: a1a6b7ea ("net: dsa: add cross-chip multicast support")
Reported-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull ceph gix from Ilya Dryomov:
 "Memory allocation flags fix, marked for stable"

* tag 'ceph-for-4.14-rc9' of git://github.com/ceph/ceph-client:
  rbd: use GFP_NOIO for parent stat and data requests

Pull input layer updates from Dmitry Torokhov:

 - a new ACPI ID for Elan touchpad found in yet another Ideapad model

 - Synaptics RMI4 will allow binding to controllers reporting SMB
   version 3 (note that we are not adding any new ACPI IDs to the
   Synaptics PS/2 drover so unless user explicitly enables intertouch
   support there is no user-visible change)

 - a fixup to TSC 2004/5 touchscreen driver to mark input devices as
   "direct" to help userspace identify the type of device they are
   dealing with

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: synaptics-rmi4 - RMI4 can also use SMBUS version 3
  Input: tsc200x-core - set INPUT_PROP_DIRECT
  Input: elan_i2c - add ELAN060C to the ACPI table

Pull KVM fix from Radim Krčmář:
 "Fix PPC HV host crash that can occur as a result of resizing the guest
  hashed page table"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Book3S HV: Fix exclusion between HPT resizing and other HPT updates

Pull MIPS fixes from James Hogan:
 "A final few MIPS fixes for 4.14:

   - fix BMIPS NULL pointer dereference (4.7)

   - fix AR7 early GPIO init allocation failure (3.19)

   - fix dead serial output on certain AR7 platforms (2.6.35)"

* tag 'mips_fixes_4.14_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: AR7: Ensure that serial ports are properly set up
  MIPS: AR7: Defer registration of GPIO
  MIPS: BMIPS: Fix missing cbr address

Following my recent transition from Imagination Technologies to the=20
reincarnated MIPS company add a .mailmap mapping for my work address,
so that `scripts/get_maintainer.pl' gets it right for past commits.
Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 941f5f0f.

Sadly, it turns out that we really can't just do the cross-CPU IPI to
all CPU's to get their proper frequencies, because it's much too
expensive on systems with lots of cores.

So we'll have to revert this for now, and revisit it using a smarter
model (probably doing one system-wide IPI at open time, and doing all
the frequency calculations in parallel).
Reported-by: WANG Chao <chao.wang@ucloud.cn>
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Rafael J Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm fixes from Dave Airlie:
 "Last few patches to wrap up.

  Two i915 fixes that are on their way to stable, one vmware black
  screen bug, and one const patch that I was going to drop, but it was
  clearly a pretty safe one liner"

* tag 'drm-fixes-for-v4.14-rc9' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Deconstruct struct sgt_dma initialiser
  drm/i915: Reject unknown syncobj flags
  drm/vmwgfx: Fix Ubuntu 17.10 Wayland black screen issue
  drm/vmwgfx: constify vmw_fence_ops

The CANFD transmitter delay calculation formula was updated in the
latest software drop from IFI and improves the behavior of the IFI
CANFD core during bitrate switching. Use the new formula to improve
stability of the CANFD operation.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Markus Marb <markus@marb.org>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>