This patch introduces vp_modern_config_vector() for setting config
vector.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-6-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

This patch introduces vp_modern_remove() doing device resources
cleanup to make it can be used.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-5-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

This patch factors out the modern device initialization logic into a
helper. Note that it still depends on the caller to enable pci device
which allows the caller to use e.g devres.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-4-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

This patch splits out the virtio-pci modern device only attributes
into another structure. While at it, a dedicated probe method for
modern only attributes is introduced. This may help for split the
logic into a dedicated module.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-3-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Instead of accessing iomem via struct virito_pci_device directly,
tweak to call the io accessors through the iomem structure. This will
ease the splitting of modern virtio device logic.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-2-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

The size of 'struct vhost_scsi' is order-10 (~2.3MB). It may take long time
delay by kzalloc() to compact memory pages by retrying multiple times when
there is a lack of high-order pages. As a result, there is latency to
create a VM (with vhost-scsi) or to hotadd vhost-scsi-based storage.

The prior commit 595cb754 ("vhost/scsi: use vmalloc for order-10
allocation") prefers to fallback only when really needed, while this patch
allocates with kvzalloc() with __GFP_NORETRY implicitly set to avoid
retrying memory pages compact for multiple times.

The __GFP_NORETRY is implicitly set if the size to allocate is more than
PAGE_SZIE and when __GFP_RETRY_MAYFAIL is not explicitly set.

Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20210123080853.4214-1-dongli.zhang@oracle.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

Enable user to create vdpasim net simulate devices.

Show vdpa management device that supports creating, deleting vdpa devices.

$ vdpa mgmtdev show
vdpasim_net:
  supported_classes
    net

$ vdpa mgmtdev show -jp
{
    "show": {
        "vdpasim_net": {
            "supported_classes": {
              "net"
        }
    }
}

Create a vdpa device of type networking named as "foo2" from
the management device vdpasim:

$ vdpa dev add mgmtdev vdpasim_net name foo2

Show the newly created vdpa device by its name:
$ vdpa dev show foo2
foo2: type network mgmtdev vdpasim_net vendor_id 0 max_vqs 2 max_vq_size 256

$ vdpa dev show foo2 -jp
{
    "dev": {
        "foo2": {
            "type": "network",
            "mgmtdev": "vdpasim_net",
            "vendor_id": 0,
            "max_vqs": 2,
            "max_vq_size": 256
        }
    }
}

Delete the vdpa device after its use:
$ vdpa dev del foo2
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-7-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Enable user to query vdpa device information.

$ vdpa dev add mgmtdev vdpasim_net name foo2

Show the newly created vdpa device by its name:
$ vdpa dev show foo2
foo2: type network mgmtdev vdpasim_net vendor_id 0 max_vqs 2 max_vq_size 256

$ vdpa dev show foo2 -jp
{
    "dev": {
        "foo2": {
            "type": "network",
            "mgmtdev": "vdpasim_net",
            "vendor_id": 0,
            "max_vqs": 2,
            "max_vq_size": 256
        }
    }
}
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-6-parav@nvidia.com

Including a memory leak fix:

Link: https://lore.kernel.org/r/20210217060614.59561-1-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Add the ability to add and delete a vdpa device.

Examples:
Create a vdpa device of type network named "foo2" from
the management device vdpasim:

$ vdpa dev add mgmtdev vdpasim_net name foo2

Delete the vdpa device after its use:
$ vdpa dev del foo2
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-5-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

To add one or more VDPA devices, define a management device which
allows adding or removing vdpa device. A management device defines
set of callbacks to manage vdpa devices.

To begin with, it defines add and remove callbacks through which a user
defined vdpa device can be added or removed.

A unique management device is identified by its unique handle identified
by management device name and optionally the bus name.

Hence, introduce routine through which driver can register a
management device and its callback operations for adding and remove
a vdpa device.

Introduce vdpa netlink socket family so that user can query management
device and its attributes.

Example of show vdpa management device which allows creating vdpa device of
networking class (device id = 0x1) of virtio specification 1.1
section 5.1.1.

$ vdpa mgmtdev show
vdpasim_net:
  supported_classes:
    net

Example of showing vdpa management device in JSON format.

$ vdpa mgmtdev show -jp
{
    "show": {
        "vdpasim_net": {
            "supported_classes": [ "net" ]
        }
    }
}
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-4-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

Including a bugfix:

vpda: correctly size vdpa_nl_policy

We need to ensure last entry of vdpa_nl_policy[]
is zero, otherwise out-of-bounds access is hurting us.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Eli Cohen <elic@nvidia.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20210210134911.4119555-1-eric.dumazet@gmail.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

In a subsequent patch, when user initiated command creates a vdpa device,
the user chooses the name of the vdpa device.
To support it, extend the device allocation API to consider this name
specified by the caller driver.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-3-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

MAC address array is used only in vdpa_sim_net.c.
Hence, keep it static.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-2-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Fix the following coccicheck warnings:

./drivers/virtio/virtio_mem.c:2580:2-25: WARNING: Assignment
of 0/1 to bool variable.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Link: https://lore.kernel.org/r/1611129031-82818-1-git-send-email-abaci-bugfix@linux.alibaba.comSigned-off-by: Tian Tao <tiantao6@hisilicon.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Pull LED fix from Pavel Machek:
 "One-liner fixing a build problem"

* 'for-rc8-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds:
  leds: rt8515: add V4L2_FLASH_LED_CLASS dependency

Merge tag 'kbuild-fixes-v5.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64

 - Use pkg-config for scripts/sign-file.c CFLAGS

* tag 'kbuild-fixes-v5.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  scripts: set proper OpenSSL include dir also for sign-file
  sparc: remove wrong comment from arch/sparc/include/asm/Kbuild
  kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64

Pull x86 fixes from Borislav Petkov:
 "I kinda knew while typing 'I hope this is the last batch of x86/urgent
  updates' last week, Murphy was reading too and uttered 'Hold my
  beer!'.

  So here's more fixes... Thanks Murphy.

  Anyway, three more x86/urgent fixes for 5.11 final. We should be
  finally ready (famous last words). :-)

   - An SGX use after free fix

   - A fix for the fix to disable CET instrumentation generation for
     kernel code. We forgot 32-bit, which we seem to do very often
     nowadays

   - A Xen PV fix to irqdomain init ordering"

* tag 'x86_urgent_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pci: Create PCI/MSI irqdomain after x86_init.pci.arch_init()
  x86/build: Disable CET instrumentation in the kernel for 32-bit too
  x86/sgx: Maintain encl->refcount for each encl->mm_list entry

The leds-rt8515 driver can optionall use the v4l2 flash led class,
but it causes a link error when that class is in a loadable module
and the rt8515 driver itself is built-in:

ld.lld: error: undefined symbol: v4l2_flash_init
>>> referenced by leds-rt8515.c
>>>               leds/flash/leds-rt8515.o:(rt8515_probe) in archive
drivers/built-in.a

Adding 'depends on V4L2_FLASH_LED_CLASS' in Kconfig would avoid that,
but it would make it impossible to use the driver without the
v4l2 support.

Add the same dependency that the other users of this class have
instead, which just prevents the broken configuration.

Fixes: e1c6edcb ("leds: rt8515: Add Richtek RT8515 LED driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

Fixes: 2cea4a7a ("scripts: use pkg-config to locate libcrypto")
Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Cc: stable@vger.kernel.org # 5.6.x
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

These are NOT exported to userspace.

The headers listed in arch/sparc/include/uapi/asm/Kbuild are exported.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull clk fix from Stephen Boyd:
 "One small fix for the Allwinner clk driver so that display clks figure
  out the correct rate to use.

  This fixes displays running 4k@60Hz and some other resolutions that
  haven't been exercised and fully understood until now"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sunxi-ng: mp: fix parent rate change flag check

Pull SCSI fix from James Bottomley:
 "One fix for scsi_debug that fixes a memory leak on module removal"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: scsi_debug: Fix a memory leak

Pull cgroup fixes from Tejun Heo:
 "Two cgroup fixes:

   - fix a NULL deref when trying to poll PSI in the root cgroup

   - fix confusing controller parsing corner case when mounting cgroup
     v1 hierarchies

  And doc / maintainer file updates"

* 'for-5.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: update PSI file description in docs
  cgroup: fix psi monitor for root cgroup
  MAINTAINERS: Update my email address
  MAINTAINERS: Remove stale URLs for cpuset
  cgroup-v1: add disabled controller check in cgroup1_parse_param()

Merge fixes from Andrew Morton:
 "6 patches.

  Subsystems affected by this patch series: mm/pagemap, scripts,
  MAINTAINERS, and h8300"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  h8300: fix PREEMPTION build, TI_PRE_COUNT undefined
  MAINTAINERS: add Andrey Konovalov to KASAN reviewers
  MAINTAINERS: update Andrey Konovalov's email address
  MAINTAINERS: update KASAN file list
  scripts/recordmcount.pl: support big endian for ARCH sh
  m68k: make __pfn_to_phys() and __phys_to_pfn() available for !MMU

Pull i2c fix from Wolfram Sang:
 "One more I2C driver bugfix"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: stm32f7: fix configuration of the digital filter

Pull btrfs fix from David Sterba:
 "A regression fix caused by a refactoring in 5.11.

  A corrupted superblock wouldn't be detected by checksum verification
  due to wrongly placed initialization of the checksum length, thus
  making memcmp always work"

* tag 'for-5.11-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: initialize fs_info::csum_size earlier in open_ctree

Fix a build error for undefined 'TI_PRE_COUNT' by adding it to
asm-offsets.c.

  h8300-linux-ld: arch/h8300/kernel/entry.o: in function `resume_kernel': (.text+0x29a): undefined reference to `TI_PRE_COUNT'

Link: https://lkml.kernel.org/r/20210212021650.22740-1-rdunlap@infradead.org
Fixes: df2078b8 ("h8300: Low level entry")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add my personal email address to KASAN reviewers list.

Link: https://lkml.kernel.org/r/c1ce89a7aae0e2d6852249c280b1eb59aeac30c0.1613150186.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use my personal email address.

Link: https://lkml.kernel.org/r/b0ec98dabbc12336c162788f5ccde97045a0d65e.1613150186.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Account for the following files:

 - lib/Kconfig.kasan

 - lib/test_kasan_module.c

 - arch/arm64/include/asm/mte-kasan.h

Link: https://lkml.kernel.org/r/7f9771d97b34d396bfdc4e288ad93486bb865a06.1613150186.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The kernel test robot reported the following issue:

    CC [M]  drivers/soc/litex/litex_soc_ctrl.o
  sh4-linux-objcopy: Unable to change endianness of input file(s)
  sh4-linux-ld: cannot find drivers/soc/litex/.tmp_gl_litex_soc_ctrl.o: No such file or directory
  sh4-linux-objcopy: 'drivers/soc/litex/.tmp_mx_litex_soc_ctrl.o': No such file

The problem is that the format of input file is elf32-shbig-linux, but
sh4-linux-objcopy wants to output a file which format is elf32-sh-linux:

  $ sh4-linux-objdump -d drivers/soc/litex/litex_soc_ctrl.o | grep format
  drivers/soc/litex/litex_soc_ctrl.o:     file format elf32-shbig-linux

Link: https://lkml.kernel.org/r/20210210150435.2171567-1-rong.a.chen@intel.com
Link: https://lore.kernel.org/linux-mm/202101261118.GbbYSlHu-lkp@intel.comSigned-off-by: Rong Chen <rong.a.chen@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recent changes that obsoleted DISCONTIGMEM on m68k switched the MMU
variant to use generic definitions of __pfn_to_phys() and __phys_to_pfn(),
but missed the !MMU variant which caused a build failure:

   drivers/media/common/videobuf2/videobuf2-dma-contig.c: In function 'vb2_dc_get_userptr':
   drivers/media/common/videobuf2/videobuf2-dma-contig.c:509:5: error: implicit declaration of function '__pfn_to_phys' [-Werror=implicit-function-declaration]
     509 |     __pfn_to_phys(nums[0]), size, buf->dma_dir, 0);
         |     ^~~~~~~~~~~~~
   cc1: some warnings being treated as errors

Enable __pfn_to_phys() and __phys_to_pfn() on !MMU builds.

Link: https://lkml.kernel.org/r/20210211232202.GS299309@linux.ibm.com
Fixes: 4bfc848e ("m68k/mm: enable use of generic memory_model.h for !DISCONTIGMEM")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull cifs fixes from Steve French:
 "Four small smb3 fixes to the new mount API (including a particularly
  important one for DFS links).

  These were found in testing this week of additional DFS scenarios, and
  a user testing of an apache container problem"

* tag '5.11-rc7-smb3-github' of git://github.com/smfrench/smb3-kernel:
  cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath.
  cifs: In the new mount api we get the full devname as source=
  cifs: do not disable noperm if multiuser mount option is not provided
  cifs: fix dfs-links

Pull io_uring fix from Jens Axboe:
 "Revert of a patch from this release that caused a regression"

* tag 'io_uring-5.11-2021-02-12' of git://git.kernel.dk/linux-block:
  Revert "io_uring: don't take fs for recvmsg/sendmsg"

Pull drm fixes from Dave Airlie:
 "Regular fixes for final, there is a ttm regression fix, dp-mst fix,
  one amdgpu revert, two i915 fixes, and some misc fixes for sun4i,
  xlnx, and vc4.

  All pretty quiet and don't think we have any known outstanding
  regressions.

  ttm:
   - page pool regression fix.

  dp_mst:
   - don't report un-attached ports as connected

  amdgpu:
   - blank screen fix

  i915:
   - ensure Type-C FIA is powered when initializing
   - fix overlay frontbuffer tracking

  sun4i:
   - tcon1 sync polarity fix
   - always set HDMI clock rate
   - fix H6 HDMI PHY config
   - fix H6 max frequency

  vc4:
   - fix buffer overflow

  xlnx:
   - fix memory leak"

* tag 'drm-fixes-2021-02-12' of git://anongit.freedesktop.org/drm/drm:
  drm/ttm: make sure pool pages are cleared
  drm/sun4i: dw-hdmi: Fix max. frequency for H6
  drm/sun4i: Fix H6 HDMI PHY configuration
  drm/sun4i: dw-hdmi: always set clock rate
  drm/sun4i: tcon: set sync polarity for tcon1 channel
  drm/i915: Fix overlay frontbuffer tracking
  Revert "drm/amd/display: Update NV1x SR latency values"
  drm/i915/tgl+: Make sure TypeC FIA is powered up when initializing it
  drm/dp_mst: Don't report ports connected if nothing is attached to them
  drm/xlnx: fix kmemleak by sending vblank_event in atomic_disable
  drm/vc4: hvs: Fix buffer overflow with the dlist handling

Pull tracing fix from Steven Rostedt:
 "Fix buffer overflow in trace event filter.

  It was reported that if an trace event was larger than a page and was
  filtered, that it caused memory corruption. The reason is that
  filtered events first go into a buffer to test the filter before being
  written into the ring buffer. Unfortunately, this write did not check
  the size"

* tag 'trace-v5.11-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Check length before giving out the filter buffer

Pull xen fix from Juergen Gross:
 "A single fix for an issue introduced this development cycle: when
  running as a Xen guest on Arm systems the kernel will hang during
  boot"

* tag 'for-linus-5.11-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  arm/xen: Don't probe xenbus as part of an early initcall

Pull RISC-V fix from Palmer Dabbelt:
 "A single fix this week: the removal of the GPIO reset method for the
  Ethernet phy on the HiFive Unleashed.

  This returns to relying on the bootloader's phy reset sequence, which
  we'll have to continue doing until we can sort out how to get the
  Linux phy driver to perform the special reset dance required for this
  phy"

* tag 'riscv-for-linus-5.11-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  Revert "dts: phy: add GPIO number and active state used for phy reset"

Pull arm64 fix from Catalin Marinas:
 "Fix PTRACE_PEEKMTETAGS access to an mmapped region before the first
  write"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mte: Allow PTRACE_PEEKMTETAGS access to the zero page

The ptrace(PTRACE_PEEKMTETAGS) implementation checks whether the user
page has valid tags (mapped with PROT_MTE) by testing the PG_mte_tagged
page flag. If this bit is cleared, ptrace(PTRACE_PEEKMTETAGS) returns
-EIO.

A newly created (PROT_MTE) mapping points to the zero page which had its
tags zeroed during cpu_enable_mte(). If there were no prior writes to
this mapping, ptrace(PTRACE_PEEKMTETAGS) fails with -EIO since the zero
page does not have the PG_mte_tagged flag set.

Set PG_mte_tagged on the zero page when its tags are cleared during
boot. In addition, to avoid ptrace(PTRACE_PEEKMTETAGS) succeeding on
!PROT_MTE mappings pointing to the zero page, change the
__access_remote_tags() check to (vm_flags & VM_MTE) instead of
PG_mte_tagged.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 34bfeea4 ("arm64: mte: Clear the tags when a page is mapped in user-space with PROT_MTE")
Cc: <stable@vger.kernel.org> # 5.10.x
Cc: Will Deacon <will@kernel.org>
Reported-by: Luis Machado <luis.machado@linaro.org>
Tested-by: Luis Machado <luis.machado@linaro.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20210210180316.23654-1-catalin.marinas@arm.com