Provide an implementation of task_cpu_possible_mask() so that we can
prevent 64-bit-only cores being added to the 'cpus_mask' for compat
tasks on systems with mismatched 32-bit support at EL0,
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-11-will@kernel.org

In preparation for restricting the affinity of a task during execve()
on arm64, introduce a new dl_task_check_affinity() helper function to
give an indication as to whether the restricted mask is admissible for
a deadline task.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lore.kernel.org/r/20210730112443.23245-10-will@kernel.org

Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.

Although userspace can carefully manage the affinity masks for such
tasks, one place where it is particularly problematic is execve()
because the CPU on which the execve() is occurring may be incompatible
with the new application image. In such a situation, it is desirable to
restrict the affinity mask of the task and ensure that the new image is
entered on a compatible CPU. From userspace's point of view, this looks
the same as if the incompatible CPUs have been hotplugged off in the
task's affinity mask. Similarly, if a subsequent execve() reverts to
a compatible image, then the old affinity is restored if it is still
valid.

In preparation for restricting the affinity mask for compat tasks on
arm64 systems without uniform support for 32-bit applications, introduce
{force,relax}_compatible_cpus_allowed_ptr(), which respectively restrict
and restore the affinity mask for a task based on the compatible CPUs.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-9-will@kernel.org

In preparation for replaying user affinity requests using a saved mask,
split sched_setaffinity() up so that the initial task lookup and
security checks are only performed when the request is coming directly
from userspace.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-8-will@kernel.org

In preparation for saving and restoring the user-requested CPU affinity
mask of a task, add a new cpumask_t pointer to 'struct task_struct'.

If the pointer is non-NULL, then the mask is copied across fork() and
freed on task exit.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-7-will@kernel.org

Reject explicit requests to change the affinity mask of a task via
set_cpus_allowed_ptr() if the requested mask is not a subset of the
mask returned by task_cpu_possible_mask(). This ensures that the
'cpus_mask' for a given task cannot contain CPUs which are incapable of
executing it, except in cases where the affinity is forced.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-6-will@kernel.org

select_fallback_rq() only needs to recheck for an allowed CPU if the
affinity mask of the task has changed since the last check.

Return a 'bool' from cpuset_cpus_allowed_fallback() to indicate whether
the affinity mask was updated, and use this to elide the allowed check
when the mask has been left alone.

No functional change.
Suggested-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-5-will@kernel.org

Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.

Modify guarantee_online_cpus() to take task_cpu_possible_mask() into
account when trying to find a suitable set of online CPUs for a given
task. This will avoid passing an invalid mask to set_cpus_allowed_ptr()
during ->attach() and will subsequently allow the cpuset hierarchy to be
taken into account when forcefully overriding the affinity mask for a
task which requires migration to a compatible CPU.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lkml.kernel.org/r/20210730112443.23245-4-will@kernel.org

If the scheduler cannot find an allowed CPU for a task,
cpuset_cpus_allowed_fallback() will widen the affinity to cpu_possible_mask
if cgroup v1 is in use.

In preparation for allowing architectures to provide their own fallback
mask, just return early if we're either using cgroup v1 or we're using
cgroup v2 with a mask that contains invalid CPUs. This will allow
select_fallback_rq() to figure out the mask by itself.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20210730112443.23245-3-will@kernel.org

Asymmetric systems may not offer the same level of userspace ISA support
across all CPUs, meaning that some applications cannot be executed by
some CPUs. As a concrete example, upcoming arm64 big.LITTLE designs do
not feature support for 32-bit applications on both clusters.

On such a system, we must take care not to migrate a task to an
unsupported CPU when forcefully moving tasks in select_fallback_rq()
in response to a CPU hot-unplug operation.

Introduce a task_cpu_possible_mask() hook which, given a task argument,
allows an architecture to return a cpumask of CPUs that are capable of
executing that task. The default implementation returns the
cpu_possible_mask, since sane machines do not suffer from per-cpu ISA
limitations that affect scheduling. The new mask is used when selecting
the fallback runqueue as a last resort before forcing a migration to the
first active CPU.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210730112443.23245-2-will@kernel.org

This extends SCHED_IDLE to cgroups.

Interface: cgroup/cpu.idle.
 0: default behavior
 1: SCHED_IDLE

Extending SCHED_IDLE to cgroups means that we incorporate the existing
aspects of SCHED_IDLE; a SCHED_IDLE cgroup will count all of its
descendant threads towards the idle_h_nr_running count of all of its
ancestor cgroups. Thus, sched_idle_rq() will work properly.
Additionally, SCHED_IDLE cgroups are configured with minimum weight.

There are two key differences between the per-task and per-cgroup
SCHED_IDLE interface:

  - The cgroup interface allows tasks within a SCHED_IDLE hierarchy to
    maintain their relative weights. The entity that is "idle" is the
    cgroup, not the tasks themselves.

  - Since the idle entity is the cgroup, our SCHED_IDLE wakeup preemption
    decision is not made by comparing the current task with the woken
    task, but rather by comparing their matching sched_entity.

A typical use-case for this is a user that creates an idle and a
non-idle subtree. The non-idle subtree will dominate competition vs
the idle subtree, but the idle subtree will still be high priority vs
other users on the system. The latter is accomplished via comparing
matching sched_entity in the waken preemption path (this could also be
improved by making the sched_idle_rq() decision dependent on the
perspective of a specific task).

For now, we maintain the existing SCHED_IDLE semantics. Future patches
may make improvements that extend how we treat SCHED_IDLE entities.

The per-task_group idle field is an integer that currently only holds
either a 0 or a 1. This is explicitly typed as an integer to allow for
further extensions to this API. For example, a negative value may
indicate a highly latency-sensitive cgroup that should be preferred
for preemption/placement/etc.
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20210730020019.1487127-2-joshdon@google.com

The scheduler currently expects NUMA node distances to be stable from
init onwards, and as a consequence builds the related data structures
once-and-for-all at init (see sched_init_numa()).

Unfortunately, on some architectures node distance is unreliable for
offline nodes and may very well change upon onlining.

Skip over offline nodes during sched_init_numa(). Track nodes that have
been onlined at least once, and trigger a build of a node's NUMA masks
when it is first onlined post-init.
Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210818074333.48645-1-srikar@linux.vnet.ibm.com

Pull powerpc fixes from Michael Ellerman:

 - Fix crashes coming out of nap on 32-bit Book3s (eg. powerbooks).

 - Fix critical and debug interrupts on BookE, seen as crashes when
   using ptrace.

 - Fix an oops when running an SMP kernel on a UP system.

 - Update pseries LPAR security flavor after partition migration.

 - Fix an oops when using kprobes on BookE.

 - Fix oops on 32-bit pmac by not calling do_IRQ() from
   timer_interrupt().

 - Fix softlockups on CPU hotplug into a CPU-less node with xive (P9).

Thanks to Cédric Le Goater, Christophe Leroy, Finn Thain, Geetika
Moolchandani, Laurent Dufour, Laurent Vivier, Nicholas Piggin, Pu Lehui,
Radu Rendec, Srikar Dronamraju, and Stan Johnson.

* tag 'powerpc-5.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/xive: Do not skip CPU-less nodes when creating the IPIs
  powerpc/interrupt: Do not call single_step_exception() from other exceptions
  powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()
  powerpc/kprobes: Fix kprobe Oops happens in booke
  powerpc/pseries: Fix update of LPAR security flavor after LPM
  powerpc/smp: Fix OOPS in topology_init()
  powerpc/32: Fix critical and debug interrupts on BOOKE
  powerpc/32s: Fix napping restore in data storage interrupt (DSI)

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for PCI/MSI and x86 interrupt startup:

   - Mask all MSI-X entries when enabling MSI-X otherwise stale unmasked
     entries stay around e.g. when a crashkernel is booted.

   - Enforce masking of a MSI-X table entry when updating it, which
     mandatory according to speification

   - Ensure that writes to MSI[-X} tables are flushed.

   - Prevent invalid bits being set in the MSI mask register

   - Properly serialize modifications to the mask cache and the mask
     register for multi-MSI.

   - Cure the violation of the affinity setting rules on X86 during
     interrupt startup which can cause lost and stale interrupts. Move
     the initial affinity setting ahead of actualy enabling the
     interrupt.

   - Ensure that MSI interrupts are completely torn down before freeing
     them in the error handling case.

   - Prevent an array out of bounds access in the irq timings code"

* tag 'irq-urgent-2021-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  driver core: Add missing kernel doc for device::msi_lock
  genirq/msi: Ensure deactivation on teardown
  genirq/timings: Prevent potential array overflow in __irq_timings_store()
  x86/msi: Force affinity setup before startup
  x86/ioapic: Force affinity setup before startup
  genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP
  PCI/MSI: Protect msi_desc::masked for multi-MSI
  PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown()
  PCI/MSI: Correct misleading comments
  PCI/MSI: Do not set invalid bits in MSI mask
  PCI/MSI: Enforce MSI[X] entry updates to be visible
  PCI/MSI: Enforce that MSI-X table entry is masked for update
  PCI/MSI: Mask all unused MSI-X entries
  PCI/MSI: Enable and mask MSI-X early

Pull locking fix from Borislav Petkov:

 - Fix a CONFIG symbol's spelling

* tag 'locking_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Use the correct rtmutex debugging config option

Pull EFI fixes from Borislav Petkov:
 "A batch of fixes for the arm64 stub image loader:

   - fix a logic bug that can make the random page allocator fail
     spuriously

   - force reallocation of the Image when it overlaps with firmware
     reserved memory regions

   - fix an oversight that defeated on optimization introduced earlier
     where images loaded at a suitable offset are never moved if booting
     without randomization

   - complain about images that were not loaded at the right offset by
     the firmware image loader"

* tag 'efi_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/libstub: arm64: Double check image alignment at entry
  efi/libstub: arm64: Warn when efi_random_alloc() fails
  efi/libstub: arm64: Relax 2M alignment again for relocatable kernels
  efi/libstub: arm64: Force Image reallocation if BSS was not reserved
  arm64: efi: kaslr: Fix occasional random alloc (and boot) failure

Pull x86 fixes from Borislav Petkov:
 "Two fixes:

   - An objdump checker fix to ignore parenthesized strings in the
     objdump version

   - Fix resctrl default monitoring groups reporting when new subgroups
     get created"

* tag 'x86_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Fix default monitoring groups reporting
  x86/tools: Fix objdump version check again

Pull KVM fixes from Paolo Bonzini:
 "ARM:

   - Plug race between enabling MTE and creating vcpus

   - Fix off-by-one bug when checking whether an address range is RAM

  x86:

   - Fixes for the new MMU, especially a memory leak on hosts with <39
     physical address bits

   - Remove bogus EFER.NX checks on 32-bit non-PAE hosts

   - WAITPKG fix"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86/mmu: Protect marking SPs unsync when using TDP MMU with spinlock
  KVM: x86/mmu: Don't step down in the TDP iterator when zapping all SPTEs
  KVM: x86/mmu: Don't leak non-leaf SPTEs when zapping all SPTEs
  KVM: nVMX: Use vmx_need_pf_intercept() when deciding if L0 wants a #PF
  kvm: vmx: Sync all matching EPTPs when injecting nested EPT fault
  KVM: x86: remove dead initialization
  KVM: x86: Allow guest to set EFER.NX=1 on non-PAE 32-bit kernels
  KVM: VMX: Use current VMCS to query WAITPKG support for MSR emulation
  KVM: arm64: Fix race when enabling KVM_ARM_CAP_MTE
  KVM: arm64: Fix off-by-one in range_is_memory

Pull SCSI fixes from James Bottomley:
 "Three minor fixes, all in drivers"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mpt3sas: Fix incorrectly assigned error return and check
  scsi: storvsc: Log TEST_UNIT_READY errors as warnings
  scsi: lpfc: Move initialization of phba->poll_list earlier to avoid crash

Pull libnvdimm fixes from Dan Williams:
 "A couple of fixes for long standing bugs, a warning fixup, and some
  miscellaneous dax cleanups.

  The bugs were recently found due to new platforms looking to use the
  ACPI NFIT "virtual" device definition, and new error injection
  capabilities to trigger error responses to label area requests. Ira's
  cleanups have been long pending, I neglected to send them earlier, and
  see no harm in including them now. This has all appeared in -next with
  no reported issues.

  Summary:

   - Fix support for NFIT "virtual" ranges (BIOS-defined memory disks)

   - Fix recovery from failed label storage areas on NVDIMM devices

   - Miscellaneous cleanups from Ira's investigation of
     dax_direct_access paths preparing for stray-write protection"

* tag 'libnvdimm-fixes-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  tools/testing/nvdimm: Fix missing 'fallthrough' warning
  libnvdimm/region: Fix label activation vs errors
  ACPI: NFIT: Fix support for virtual SPA ranges
  dax: Ensure errno is returned from dax_direct_access
  fs/dax: Clarify nr_pages to dax_direct_access()
  fs/fuse: Remove unneeded kaddr parameter

Pull USB fix from Greg KH:
 "A single revert of a commit that caused problems in 5.14-rc5 for
  5.14-rc6. It has been in linux-next almost all week, and has resolved
  the issues that were reported on lots of different systems that were
  not the platform that the change was originally tested on (gotta love
  SoC cores used in multiple devices from multiple vendors...)"

* tag 'usb-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  Revert "usb: dwc3: gadget: Use list_replace_init() before traversing lists"

Pull IIO driver fixes from Greg KH:
 "Here are some small IIO driver fixes for reported problems for
  5.14-rc6 (no staging driver fixes at the moment).

  All of them resolve reported issues and have been in linux-next all
  week with no reported problems. Full details are in the shortlog"

* tag 'staging-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: adc: Fix incorrect exit of for-loop
  iio: humidity: hdc100x: Add margin to the conversion time
  dt-bindings: iio: st: Remove wrong items length check
  iio: accel: fxls8962af: fix i2c dependency
  iio: adis: set GPIO reset pin direction
  iio: adc: ti-ads7950: Ensure CS is deasserted after reading channels
  iio: accel: fxls8962af: fix potential use of uninitialized symbol

Pull i2c fixes from Wolfram Sang:
 "One driver bugfix, a documentation bugfix, and an "uninitialized data"
  leak fix for the core"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Documentation: i2c: add i2c-sysfs into index
  i2c: dev: zero out array used for i2c reads from userspace
  i2c: iproc: fix race between client unreg and tasklet

Pull xen fixes from Juergen Gross:
 "A small cleanup patch and a fix of a rare race in the Xen evtchn
  driver"

* tag 'for-linus-5.14-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/events: Fix race in set_evtchn_to_irq
  xen/events: remove redundant initialization of variable irq

Pull RISC-V fixes from Palmer Dabbelt:

 - avoid passing -mno-relax to compilers that don't support it

 - a comment fix

* tag 'riscv-for-linus-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE
  riscv: kexec: do not add '-mno-relax' flag if compiler doesn't support it

Pull configfs fix from Christoph Hellwig:

 - fix to revert to the historic write behavior (Bart Van Assche)

* tag 'configfs-5.14' of git://git.infradead.org/users/hch/configfs:
  configfs: restore the kernel v5.13 text attribute write behavior

Merge misc fixes from Andrew Morton:
 "7 patches.

  Subsystems affected by this patch series: mm (kasan, mm/slub,
  mm/madvise, and memcg), and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib: use PFN_PHYS() in devmem_is_allowed()
  mm/memcg: fix incorrect flushing of lruvec data in obj_stock
  mm/madvise: report SIGBUS as -EFAULT for MADV_POPULATE_(READ|WRITE)
  mm: slub: fix slub_debug disabling for list of slabs
  slub: fix kmalloc_pagealloc_invalid_free unit test
  kasan, slub: reset tag when printing address
  kasan, kmemleak: reset tags when scanning block

Pull cifs fixes from Steve French:
 "Four CIFS/SMB3 Fixes, all for stable, two relating to deferred close,
  and one for the 'modefromsid' mount option (when 'idsfromsid' not
  specified)"

* tag '5.14-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Call close synchronously during unlink/rename/lease break.
  cifs: Handle race conditions during rename
  cifs: use the correct max-length for dentry_path_raw()
  cifs: create sd context must be a multiple of 8

Merge tag 'linux-kselftest-fixes-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fix from Shuah Khan:
 "A single patch to sgx test to fix Q1 and Q2 calculation"

* tag 'linux-kselftest-fixes-5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/sgx: Fix Q1 and Q2 calculation in sigstruct.c

The physical address may exceed 32 bits on 32-bit systems with more than
32 bits of physcial address.  Use PFN_PHYS() in devmem_is_allowed(), or
the physical address may overflow and be truncated.

We found this bug when mapping a high addresses through devmem tool,
when CONFIG_STRICT_DEVMEM is enabled on the ARM with ARM_LPAE and devmem
is used to map a high address that is not in the iomem address range, an
unexpected error indicating no permission is returned.

This bug was initially introduced from v2.6.37, and the function was
moved to lib in v5.11.

Link: https://lkml.kernel.org/r/20210731025057.78825-1-wangliang101@huawei.com
Fixes: 087aaffc ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem")
Fixes: 527701ed ("lib: Add a generic version of devmem_is_allowed()")
Signed-off-by: Liang Wang <wangliang101@huawei.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Liang Wang <wangliang101@huawei.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: <stable@vger.kernel.org>	[2.6.37+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When mod_objcg_state() is called with a pgdat that is different from
that in the obj_stock, the old lruvec data cached in obj_stock are
flushed out.  Unfortunately, they were flushed to the new pgdat and so
the data go to the wrong node.  This will screw up the slab data
reported in /sys/devices/system/node/node*/meminfo.

Fix that by flushing the data to the cached pgdat instead.

Link: https://lkml.kernel.org/r/20210802143834.30578-1-longman@redhat.com
Fixes: 68ac5b3c ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Doing some extended tests and polishing the man page update for
MADV_POPULATE_(READ|WRITE), I realized that we end up converting also
SIGBUS (via -EFAULT) to -EINVAL, making it look like yet another
madvise() user error.

We want to report only problematic mappings and permission problems that
the user could have know as -EINVAL.

Let's not convert -EFAULT arising due to SIGBUS (or SIGSEGV) to -EINVAL,
but instead indicate -EFAULT to user space.  While we could also convert
it to -ENOMEM, using -EFAULT looks more helpful when user space might
want to troubleshoot what's going wrong: MADV_POPULATE_(READ|WRITE) is
not part of an final Linux release and we can still adjust the behavior.

Link: https://lkml.kernel.org/r/20210726154932.102880-1-david@redhat.com
Fixes: 4ca9b385 ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Vijayanand Jitta reports:

  Consider the scenario where CONFIG_SLUB_DEBUG_ON is set and we would
  want to disable slub_debug for few slabs. Using boot parameter with
  slub_debug=-,slab_name syntax doesn't work as expected i.e; only
  disabling debugging for the specified list of slabs. Instead it
  disables debugging for all slabs, which is wrong.

This patch fixes it by delaying the moment when the global slub_debug
flags variable is updated.  In case a "slub_debug=-,slab_name" has been
passed, the global flags remain as initialized (depending on
CONFIG_SLUB_DEBUG_ON enabled or disabled) and are not simply reset to 0.

Link: https://lkml.kernel.org/r/8a3d992a-473a-467b-28a0-4ad2ff60ab82@suse.czSigned-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reviewed-by: Vijayanand Jitta <vjitta@codeaurora.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The unit test kmalloc_pagealloc_invalid_free makes sure that for the
higher order slub allocation which goes to page allocator, the free is
called with the correct address i.e.  the virtual address of the head
page.

Commit f227f0fa ("slub: fix unreclaimable slab stat for bulk free")
unified the free code paths for page allocator based slub allocations
but instead of using the address passed by the caller, it extracted the
address from the page.  Thus making the unit test
kmalloc_pagealloc_invalid_free moot.  So, fix this by using the address
passed by the caller.

Should we fix this? I think yes because dev expect kasan to catch these
type of programming bugs.

Link: https://lkml.kernel.org/r/20210802180819.1110165-1-shakeelb@google.com
Fixes: f227f0fa ("slub: fix unreclaimable slab stat for bulk free")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The address still includes the tags when it is printed.  With hardware
tag-based kasan enabled, we will get a false positive KASAN issue when
we access metadata.

Reset the tag before we access the metadata.

Link: https://lkml.kernel.org/r/20210804090957.12393-3-Kuan-Ying.Lee@mediatek.com
Fixes: aa1ef4d7 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "kasan, slub: reset tag when printing address", v3.

With hardware tag-based kasan enabled, we reset the tag when we access
metadata to avoid from false alarm.

This patch (of 2):

Kmemleak needs to scan kernel memory to check memory leak.  With hardware
tag-based kasan enabled, when it scans on the invalid slab and
dereference, the issue will occur as below.

Hardware tag-based KASAN doesn't use compiler instrumentation, we can not
use kasan_disable_current() to ignore tag check.

Based on the below report, there are 11 0xf7 granules, which amounts to
176 bytes, and the object is allocated from the kmalloc-256 cache.  So
when kmemleak accesses the last 256-176 bytes, it causes faults, as those
are marked with KASAN_KMALLOC_REDZONE == KASAN_TAG_INVALID == 0xfe.

Thus, we reset tags before accessing metadata to avoid from false positives.

  BUG: KASAN: out-of-bounds in scan_block+0x58/0x170
  Read at addr f7ff0000c0074eb0 by task kmemleak/138
  Pointer tag: [f7], memory tag: [fe]

  CPU: 7 PID: 138 Comm: kmemleak Not tainted 5.14.0-rc2-00001-g8cae8cd8-dirty #134
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x0/0x1b0
   show_stack+0x1c/0x30
   dump_stack_lvl+0x68/0x84
   print_address_description+0x7c/0x2b4
   kasan_report+0x138/0x38c
   __do_kernel_fault+0x190/0x1c4
   do_tag_check_fault+0x78/0x90
   do_mem_abort+0x44/0xb4
   el1_abort+0x40/0x60
   el1h_64_sync_handler+0xb4/0xd0
   el1h_64_sync+0x78/0x7c
   scan_block+0x58/0x170
   scan_gray_list+0xdc/0x1a0
   kmemleak_scan+0x2ac/0x560
   kmemleak_scan_thread+0xb0/0xe0
   kthread+0x154/0x160
   ret_from_fork+0x10/0x18

  Allocated by task 0:
   kasan_save_stack+0x2c/0x60
   __kasan_kmalloc+0xec/0x104
   __kmalloc+0x224/0x3c4
   __register_sysctl_paths+0x200/0x290
   register_sysctl_table+0x2c/0x40
   sysctl_init+0x20/0x34
   proc_sys_init+0x3c/0x48
   proc_root_init+0x80/0x9c
   start_kernel+0x648/0x6a4
   __primary_switched+0xc0/0xc8

  Freed by task 0:
   kasan_save_stack+0x2c/0x60
   kasan_set_track+0x2c/0x40
   kasan_set_free_info+0x44/0x54
   ____kasan_slab_free.constprop.0+0x150/0x1b0
   __kasan_slab_free+0x14/0x20
   slab_free_freelist_hook+0xa4/0x1fc
   kfree+0x1e8/0x30c
   put_fs_context+0x124/0x220
   vfs_kern_mount.part.0+0x60/0xd4
   kern_mount+0x24/0x4c
   bdev_cache_init+0x70/0x9c
   vfs_caches_init+0xdc/0xf4
   start_kernel+0x638/0x6a4
   __primary_switched+0xc0/0xc8

  The buggy address belongs to the object at ffff0000c0074e00
   which belongs to the cache kmalloc-256 of size 256
  The buggy address is located 176 bytes inside of
   256-byte region [ffff0000c0074e00, ffff0000c0074f00)
  The buggy address belongs to the page:
  page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x100074
  head:(____ptrval____) order:2 compound_mapcount:0 compound_pincount:0
  flags: 0xbfffc0000010200(slab|head|node=0|zone=2|lastcpupid=0xffff|kasantag=0x0)
  raw: 0bfffc0000010200 0000000000000000 dead000000000122 f5ff0000c0002300
  raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff0000c0074c00: f0 f0 f0 f0 f0 f0 f0 f0 f0 fe fe fe fe fe fe fe
   ffff0000c0074d00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
  >ffff0000c0074e00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 fe fe fe fe fe
                                                      ^
   ffff0000c0074f00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
   ffff0000c0075000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================
  Disabling lock debugging due to kernel taint
  kmemleak: 181 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

Link: https://lkml.kernel.org/r/20210804090957.12393-1-Kuan-Ying.Lee@mediatek.com
Link: https://lkml.kernel.org/r/20210804090957.12393-2-Kuan-Ying.Lee@mediatek.comSigned-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull block fixes from Jens Axboe:
 "A few fixes for block that should go into 5.14:

   - Revert the mq-deadline cgroup addition. More work is needed on this
     front, let's revert it for now and get it right before having it in
     a released kernel (Tejun)

   - blk-iocost lockdep fix (Ming)

   - nbd double completion fix (Xie)

   - Fix for non-idling when clearing the shared tag flag (Yu)"

* tag 'block-5.14-2021-08-13' of git://git.kernel.dk/linux-block:
  nbd: Aovid double completion of a request
  blk-mq: clear active_queues before clearing BLK_MQ_F_TAG_QUEUE_SHARED
  Revert "block/mq-deadline: Add cgroup support"
  blk-iocost: fix lockdep warning on blkcg->lock

Pull io_uring fixes from Jens Axboe:
 "A bit bigger than the previous weeks, but mostly just a few stable
  bound fixes. In detail:

   - Followup fixes to patches from last week for io-wq, turns out they
     weren't complete (Hao)

   - Two lockdep reported fixes out of the RT camp (me)

   - Sync the io_uring-cp example with liburing, as a few bug fixes
     never made it to the kernel carried version (me)

   - SQPOLL related TIF_NOTIFY_SIGNAL fix (Nadav)

   - Use WRITE_ONCE() when writing sq flags (Nadav)

   - io_rsrc_put_work() deadlock fix (Pavel)"

* tag 'io_uring-5.14-2021-08-13' of git://git.kernel.dk/linux-block:
  tools/io_uring/io_uring-cp: sync with liburing example
  io_uring: fix ctx-exit io_rsrc_put_work() deadlock
  io_uring: drop ctx->uring_lock before flushing work item
  io-wq: fix IO_WORKER_F_FIXED issue in create_io_worker()
  io-wq: fix bug of creating io-wokers unconditionally
  io_uring: rsrc ref lock needs to be IRQ safe
  io_uring: Use WRITE_ONCE() when writing to sq_flags
  io_uring: clear TIF_NOTIFY_SIGNAL when running task work