If of_property_count_u32_elems returned 0, return -EINVAL to indicate
a failure. Previously this would return 0.

Fixes: a0f160ff ("pinctrl: add pinctrl/GPIO driver for Apple SoCs")
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-12-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

This expresses the intention clearer.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-11-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

The gpio core code sets of_node, so no need to do it here.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-10-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Having this missing, but everything else valid shouldn't result
in a failure.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-9-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-8-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Try to make this more readable by not using a long line with
a ternary operator.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-7-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Explicitly return 0 if the regmap_read fails.
Also change a uint32_t to a u32.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-6-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is needed for the BIT(n) macro.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-5-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

This is the preferred comment style.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-4-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add a missing comma at the end of the regmap initialisation.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-3-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Reflow some of the code now that the extra '_gpio' was removed.
Signed-off-by: NJoey Gouly <joey.gouly@arm.com>
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20211121165642.27883-2-joey.gouly@arm.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Linux 5.16-rc2 is needed because nonurgent fixes headed
for next are strongly textually dependent on a fix that
was applied for rc2.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Suggested-by: NIvaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
Signed-off-by: NDominik Kobinski <dominikkobinski314@gmail.com>
Link: https://lore.kernel.org/r/20211125215626.62447-1-dominikkobinski314@gmail.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Adopt regmap instead of a direct memory map so that custom regmaps and
other interfaces can be supported.
Signed-off-by: NColin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20211119195928.2498441-5-colin.foster@in-advantage.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

In order to allow external control via SPI, memory-mapped areas must be
changed to use the generic regmap interface. This is step 1, and is
followed by an implementation that allows a custom regmap.
Signed-off-by: NColin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20211119195928.2498441-4-colin.foster@in-advantage.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

struct gpio_chip recommends passing -1 as base to gpiolib. Doing so avoids
conflicts when the chip is external and gpiochip0 already exists.
Signed-off-by: NColin Foster <colin.foster@in-advantage.com>
Tested-by: NClément Léger <clement.leger@bootlin.com>
Link: https://lore.kernel.org/r/20211119195928.2498441-3-colin.foster@in-advantage.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Simple cleanup to make two function calls only one.
Signed-off-by: NColin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20211119195928.2498441-2-colin.foster@in-advantage.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

In arch/arm/boot/dts/uniphier-pinctrl.dtsi, there are child nodes of
pinctrl that defines pinmux and pincfg, however, there are no rules about
that in dt-bindings.

'make dtbs_check' results an error with the following message:

   pinctrl: 'ain1', 'ain2', 'ainiec1', 'aout', 'aout1', 'aout2', ...
   ... 'usb2', 'usb3' do not match any of the regexes: 'pinctrl-[0-9]+'

To avoid the issue, add the rules of pinmux and pincfg in each child node
and grandchild node.
Signed-off-by: NKunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1636416699-21033-1-git-send-email-hayashi.kunihiko@socionext.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add compatible strings for pm2250 SPMI GPIO to documentation.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1637076915-3280-2-git-send-email-loic.poulain@linaro.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

PM2250, commonly combined with QCM2290, provides ten SPMI GPIOs.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1637076915-3280-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

sc7280 supports the egpio feature, GPIOs ranging from 144 to 174
(31 GPIOs) support it, we define gpio_func to 9, which
is an unused function for all these pins on sc7280.
Signed-off-by: NRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1637041084-3299-2-git-send-email-rnayak@codeaurora.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

egpio is a scheme which allows special power Island Domain IOs
(LPASS,SSC) to be reused as regular chip GPIOs by muxing regular
TLMM functions with Island Domain functions.
With this scheme, an IO can be controlled both by the cpu running
linux and the Island processor. This provides great flexibility to
re-purpose the Island IOs for regular TLMM usecases.

2 new bits are added to ctl_reg, egpio_present is a read only bit
which shows if egpio feature is available or not on a given gpio.
egpio_enable is the read/write bit and only effective if egpio_present
is 1. Once its set, the Island IO is controlled from Chip TLMM.
egpio_enable when set to 0 means the GPIO is used as Island Domain IO.

To support this we add a new function 'egpio' which can be used to
set the egpio_enable to 0, for any other TLMM controlled functions
we set the egpio_enable to 1.
Signed-off-by: NPrasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: NRajendra Nayak <rnayak@codeaurora.org>
Link: https://lore.kernel.org/r/1637041084-3299-1-git-send-email-rnayak@codeaurora.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

PM8019 provides 6 GPIOs. Add a compatible to support that.
Signed-off-by: NKonrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211112115342.17100-2-konrad.dybcio@somainline.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add pmic-gpio compatible string for pm8019 pmic.
Signed-off-by: NKonrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211112115342.17100-1-konrad.dybcio@somainline.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add initial Qualcomm SDX65 pinctrl driver to support pin configuration
with pinctrl framework for SDX65 SoC.
Signed-off-by: NVamsi Krishna Lanka <quic_vamslank@quicinc.com>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/13acb3cb36349487dee9745ab040d8f1344d2096.1637048107.git.quic_vamslank@quicinc.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add device tree binding Documentation details for Qualcomm SDX65
pinctrl driver.
Signed-off-by: NVamsi Krishna Lanka <quic_vamslank@quicinc.com>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/06234768890dc7572226f23d432e5a69a4d5b305.1637048107.git.quic_vamslank@quicinc.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch extends pinctrl-ocelot driver to support also the
lan966x. Register layout is same as ocelot. It has 78 GPIOs.
Requires 3 registers ALT0, ALT1, ALT2 to configure ALT mode.
Signed-off-by: NKavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211118112548.14582-3-kavyasree.kotagiri@microchip.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add documentation for the compatible designated for lan966x.
Signed-off-by: NKavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Acked-by: NRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211118112548.14582-2-kavyasree.kotagiri@microchip.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Pull x86 fixes from Thomas Gleixner:

 - Move the command line preparation and the early command line parsing
   earlier so that the command line parameters which affect
   early_reserve_memory(), e.g. efi=nosftreserve, are taken into
   account. This was broken when the invocation of
   early_reserve_memory() was moved recently.

 - Use an atomic type for the SGX page accounting, which is read and
   written locklessly, to plug various race conditions related to it.

* tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Fix free page accounting
  x86/boot: Pull up cmdline preparation and early param parsing

Pull x86 perf fixes from Thomas Gleixner:

 - Remove unneded PEBS disabling when taking LBR snapshots to prevent an
   unchecked MSR access error.

 - Fix IIO event constraints for Snowridge and Skylake server chips.

* tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/perf: Fix snapshot_branch_stack warning in VM
  perf/x86/intel/uncore: Fix IIO event constraints for Snowridge
  perf/x86/intel/uncore: Fix IIO event constraints for Skylake Server
  perf/x86/intel/uncore: Fix filter_tid mask for CHA events on Skylake Server

Pull more powerpc fixes from Michael Ellerman:

 - Fix a bug in copying of sigset_t for 32-bit systems, which caused X
   to not start.

 - Fix handling of shared LSIs (rare) with the xive interrupt controller
   (Power9/10).

 - Fix missing TOC setup in some KVM code, which could result in oopses
   depending on kernel data layout.

 - Fix DMA mapping when we have persistent memory and only one DMA
   window available.

 - Fix further problems with STRICT_KERNEL_RWX on 8xx, exposed by a
   recent fix.

 - A couple of other minor fixes.

Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Cédric Le Goater,
Christian Zigotzky, Christophe Leroy, Daniel Axtens, Finn Thain, Greg
Kurz, Masahiro Yamada, Nicholas Piggin, and Uwe Kleine-König.

* tag 'powerpc-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/xive: Change IRQ domain to a tree domain
  powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX
  powerpc/signal32: Fix sigset_t copy
  powerpc/book3e: Fix TLBCAM preset at boot
  powerpc/pseries/ddw: Do not try direct mapping with persistent memory and one window
  powerpc/pseries/ddw: simplify enable_ddw()
  powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent memory"
  powerpc/pseries: Fix numa FORM2 parsing fallback code
  powerpc/pseries: rename numa_dist_table to form2_distances
  powerpc: clean vdso32 and vdso64 directories
  powerpc/83xx/mpc8349emitx: Drop unused variable
  KVM: PPC: Book3S HV: Use GLOBAL_TOC for kvmppc_h_set_dabr/xdabr()

On 32-bit:

    fs/pstore/blk.c: In function ‘__best_effort_init’:
    include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=]
	5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
	  |                  ^~~~~~
    include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’
       14 | #define KERN_INFO KERN_SOH "6" /* informational */
	  |                   ^~~~~~~~
    include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’
      373 |  printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
	  |         ^~~~~~~~~
    fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’
      314 |   pr_info("attached %s (%zu) (no dedicated panic_write!)\n",
	  |   ^~~~~~~

Cc: stable@vger.kernel.org
Fixes: 7bb9557b ("pstore/blk: Use the normal block device I/O path")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge misc fixes from Andrew Morton:
 "15 patches.

  Subsystems affected by this patch series: ipc, hexagon, mm (swap,
  slab-generic, kmemleak, hugetlb, kasan, damon, and highmem), and proc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  proc/vmcore: fix clearing user buffer by properly using clear_user()
  kmap_local: don't assume kmap PTEs are linear arrays in memory
  mm/damon/dbgfs: fix missed use of damon_dbgfs_lock
  mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation
  kasan: test: silence intentional read overflow warnings
  hugetlb, userfaultfd: fix reservation restore on userfaultfd error
  hugetlb: fix hugetlb cgroup refcounting during mremap
  mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag
  hexagon: ignore vmlinux.lds
  hexagon: clean up timer-regs.h
  hexagon: export raw I/O routines for modules
  mm: emit the "free" trace report before freeing memory in kmem_cache_free()
  shm: extend forced shm destroy to support objects from several IPC nses
  ipc: WARN if trying to remove ipc object which is absent
  mm/swap.c:put_pages_list(): reinitialise the page list

Pull block fixes from Jens Axboe:

 - Flip a cap check to avoid a selinux error (Alistair)

 - Fix for a regression this merge window where we can miss a queue ref
   put (me)

 - Un-mark pstore-blk as broken, as the condition that triggered that
   change has been rectified (Kees)

 - Queue quiesce and sync fixes (Ming)

 - FUA insertion fix (Ming)

 - blk-cgroup error path put fix (Yu)

* tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block:
  blk-mq: don't insert FUA request with data into scheduler queue
  blk-cgroup: fix missing put device in error path from blkg_conf_pref()
  block: avoid to quiesce queue in elevator_init_mq
  Revert "mark pstore-blk as broken"
  blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()
  block: fix missing queue put in error path
  block: Check ADMIN before NICE for IOPRIO_CLASS_RT

Pull pin control fixes from Linus Walleij:
 "There is an ACPI stubs fix which is ACKed by the ACPI maintainer for
  merging through my tree.

  One item stand out and that is that I delete the <linux/sdb.h> header
  that is used by nothing. I deleted this subsystem (through the GPIO
  tree) a while back so I feel responsible for tidying up the floor.

  Other than that it is the usual mistakes, a bit noisy around build
  issue and Kconfig then driver fixes.

  Specifics:

   - Fix some stubs causing compile issues for ACPI.

   - Fix some wakeups on AMD IRQs shared between GPIO and SCI.

   - Fix a build warning in the Tegra driver.

   - Fix a Kconfig issue in the Qualcomm driver.

   - Add a missing include the RALink driver.

   - Return a valid type for the Apple pinctrl IRQs.

   - Implement some Qualcomm SDM845 dual-edge errata.

   - Remove the unused <linux/sdb.h> header. (The subsystem was once
     deleted by the pinctrl maintainer...)

   - Fix a duplicate initialized in the Tegra driver.

   - Fix register offsets for UFS and SDC in the Qualcomm SM8350 driver"

* tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: qcom: sm8350: Correct UFS and SDC offsets
  pinctrl: tegra194: remove duplicate initializer again
  Remove unused header <linux/sdb.h>
  pinctrl: qcom: sdm845: Enable dual edge errata
  pinctrl: apple: Always return valid type in apple_gpio_irq_type
  pinctrl: ralink: include 'ralink_regs.h' in 'pinctrl-mt7620.c'
  pinctrl: qcom: fix unmet dependencies on GPIOLIB for GPIOLIB_IRQCHIP
  pinctrl: tegra: Return const pointer from tegra_pinctrl_get_group()
  pinctrl: amd: Fix wakeups when IRQ is shared with SCI
  ACPI: Add stubs for wakeup handler functions

Pull s390 updates from Heiko Carstens:

 - Add missing Kconfig option for ftrace direct multi sample, so it can
   be compiled again, and also add s390 support for this sample.

 - Update Christian Borntraeger's email address.

 - Various fixes for memory layout setup. Besides other this makes it
   possible to load shared DCSS segments again.

 - Fix copy to user space of swapped kdump oldmem.

 - Remove -mstack-guard and -mstack-size compile options when building
   vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled and
   results in broken vdso code which causes more or less random
   exceptions. Also remove the not needed -nostdlib option.

 - Fix memory leak on cpu hotplug and return code handling in kexec
   code.

 - Wire up futex_waitv system call.

 - Replace snprintf with sysfs_emit where appropriate.

* tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  ftrace/samples: add s390 support for ftrace direct multi sample
  ftrace/samples: add missing Kconfig option for ftrace direct multi sample
  MAINTAINERS: update email address of Christian Borntraeger
  s390/kexec: fix memory leak of ipl report buffer
  s390/kexec: fix return code handling
  s390/dump: fix copying to user-space of swapped kdump oldmem
  s390: wire up sys_futex_waitv system call
  s390/vdso: filter out -mstack-guard and -mstack-size
  s390/vdso: remove -nostdlib compiler flag
  s390: replace snprintf in show functions with sysfs_emit
  s390/boot: simplify and fix kernel memory layout setup
  s390/setup: re-arrange memblock setup
  s390/setup: avoid using memblock_enforce_memory_limit
  s390/setup: avoid reserving memory above identity mapping

Pull cifs fixes from Steve French:
 "Three small cifs/smb3 fixes: two to address minor coverity issues and
  one cleanup"

* tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: introduce cifs_ses_mark_for_reconnect() helper
  cifs: protect srv_count with cifs_tcp_ses_lock
  cifs: move debug print out of spinlock

To clear a user buffer we cannot simply use memset, we have to use
clear_user().  With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":

  systemd[1]: Starting Kdump Vmcore Save Service...
  kdump[420]: Kdump is using the default log level(3).
  kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
  kdump[465]: saving vmcore-dmesg.txt complete
  kdump[467]: saving vmcore
  BUG: unable to handle page fault for address: 00007f2374e01000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0003) - permissions violation
  PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
  Oops: 0003 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
  RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
  Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
  RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
  RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
  RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
  RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
  R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
  R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
  FS:  00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
  Call Trace:
   read_vmcore+0x236/0x2c0
   proc_reg_read+0x55/0xa0
   vfs_read+0x95/0x190
   ksys_read+0x4f/0xc0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access.  In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().

To fix, properly use clear_user() when we're dealing with a user buffer.

Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 997c136f ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NBaoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kmap_local conversion broke the ARM architecture, because the new
code assumes that all PTEs used for creating kmaps form a linear array
in memory, and uses array indexing to look up the kmap PTE belonging to
a certain kmap index.

On ARM, this cannot work, not only because the PTE pages may be
non-adjacent in memory, but also because ARM/!LPAE interleaves hardware
entries and extended entries (carrying software-only bits) in a way that
is not compatible with array indexing.

Fortunately, this only seems to affect configurations with more than 8
CPUs, due to the way the per-CPU kmap slots are organized in memory.

Work around this by permitting an architecture to set a Kconfig symbol
that signifies that the kmap PTEs do not form a lineary array in memory,
and so the only way to locate the appropriate one is to walk the page
tables.

Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/
Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org
Fixes: 2a15ba82 ("ARM: highmem: Switch to generic kmap atomic")
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
Reported-by: NQuanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>