Linus Torvalds [Sun, 28 Feb 2021 19:45:25 +0000 (11:45 -0800)]
Merge tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull more xfs updates from Darrick Wong:
"The most notable fix here prevents premature reuse of freed metadata
blocks, and adding the ability to detect accidental nested
transactions, which are not allowed here.
- Restore a disused sysctl control knob that was inadvertently
dropped during the merge window to avoid fstests regressions.
- Don't speculatively release freed blocks from the busy list until
we're actually allocating them, which fixes a rare log recovery
regression.
- Don't nest transactions when scanning for free space.
- Add an idiot^Wmaintainer light to detect nested transactions. ;)"
* tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: use current->journal_info for detecting transaction recursion
xfs: don't nest transactions when scanning for eofblocks
xfs: don't reuse busy extents on extent trim
xfs: restore speculative_cow_prealloc_lifetime sysctl
Linus Torvalds [Sun, 28 Feb 2021 19:23:38 +0000 (11:23 -0800)]
Merge tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block
Pull more block updates from Jens Axboe:
"A few stragglers (and one due to me missing it originally), and fixes
for changes in this merge window mostly. In particular:
- blktrace cleanups (Chaitanya, Greg)
- Kill dead blk_pm_* functions (Bart)
- Fixes for the bio alloc changes (Christoph)
- Fix for the partition changes (Christoph, Ming)
- Fix for turning off iopoll with polled IO inflight (Jeffle)
- nbd disconnect fix (Josef)
- loop fsync error fix (Mauricio)
- kyber update depth fix (Yang)
- max_sectors alignment fix (Mikulas)
- Add bio_max_segs helper (Matthew)"
* tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits)
block: Add bio_max_segs
blktrace: fix documentation for blk_fill_rw()
block: memory allocations in bounce_clone_bio must not fail
block: remove the gfp_mask argument to bounce_clone_bio
block: fix bounce_clone_bio for passthrough bios
block-crypto-fallback: use a bio_set for splitting bios
block: fix logging on capacity change
blk-settings: align max_sectors on "logical_block_size" boundary
block: reopen the device in blkdev_reread_part
block: don't skip empty device in in disk_uevent
blktrace: remove debugfs file dentries from struct blk_trace
nbd: handle device refs for DESTROY_ON_DISCONNECT properly
kyber: introduce kyber_depth_updated()
loop: fix I/O error on fsync() in detached loop devices
block: fix potential IO hang when turning off io_poll
block: get rid of the trace rq insert wrapper
blktrace: fix blk_rq_merge documentation
blktrace: fix blk_rq_issue documentation
blktrace: add blk_fill_rwbs documentation comment
block: remove superfluous param in blk_fill_rwbs()
...
Linus Torvalds [Sat, 27 Feb 2021 16:29:02 +0000 (08:29 -0800)]
Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block
Pull io_uring thread rewrite from Jens Axboe:
"This converts the io-wq workers to be forked off the tasks in question
instead of being kernel threads that assume various bits of the
original task identity.
This kills > 400 lines of code from io_uring/io-wq, and it's the worst
part of the code. We've had several bugs in this area, and the worry
is always that we could be missing some pieces for file types doing
unusual things (recent /dev/tty example comes to mind, userfaultfd
reads installing file descriptors is another fun one... - both of
which need special handling, and I bet it's not the last weird oddity
we'll find).
With these identical workers, we can have full confidence that we're
never missing anything. That, in itself, is a huge win. Outside of
that, it's also more efficient since we're not wasting space and code
on tracking state, or switching between different states.
I'm sure we're going to find little things to patch up after this
series, but testing has been pretty thorough, from the usual
regression suite to production. Any issue that may crop up should be
manageable.
There's also a nice series of further reductions we can do on top of
this, but I wanted to get the meat of it out sooner rather than later.
The general worry here isn't that it's fundamentally broken. Most of
the little issues we've found over the last week have been related to
just changes in how thread startup/exit is done, since that's the main
difference between using kthreads and these kinds of threads. In fact,
if all goes according to plan, I want to get this into the 5.10 and
5.11 stable branches as well.
That said, the changes outside of io_uring/io-wq are:
- arch setup, simple one-liner to each arch copy_thread()
implementation.
- Removal of net and proc restrictions for io_uring, they are no
longer needed or useful"
* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
io-wq: remove now unused IO_WQ_BIT_ERROR
io_uring: fix SQPOLL thread handling over exec
io-wq: improve manager/worker handling over exec
io_uring: ensure SQPOLL startup is triggered before error shutdown
io-wq: make buffered file write hashed work map per-ctx
io-wq: fix race around io_worker grabbing
io-wq: fix races around manager/worker creation and task exit
io_uring: ensure io-wq context is always destroyed for tasks
arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
io_uring: cleanup ->user usage
io-wq: remove nr_process accounting
io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
net: remove cmsg restriction from io_uring based send/recvmsg calls
Revert "proc: don't allow async path resolution of /proc/self components"
Revert "proc: don't allow async path resolution of /proc/thread-self components"
io_uring: move SQPOLL thread io-wq forked worker
io-wq: make io_wq_fork_thread() available to other users
io-wq: only remove worker from free_list, if it was there
io_uring: remove io_identity
io_uring: remove any grabbing of context
...
Linus Torvalds [Sat, 27 Feb 2021 15:55:27 +0000 (07:55 -0800)]
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
"Three more bugfixes and one revert. I accidently applied one patch too
early"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: exynos5: Preserve high speed master code
Revert "i2c: i2c-qcom-geni: Add shutdown callback for i2c"
i2c: designware: Get right data length
i2c: brcmstb: Fix brcmstd_send_i2c_cmd condition
It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the
sign to be the same. Introduce bio_max_segs() and change BIO_MAX_PAGES to
be unsigned to make it easier for the users.
Linus Torvalds [Fri, 26 Feb 2021 22:21:18 +0000 (14:21 -0800)]
Merge tag 'docs-5.12-2' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"A handful of late-arriving documentation fixes, nothing all that
notable"
* tag 'docs-5.12-2' of git://git.lwn.net/linux:
docs: proc.rst: fix indentation warning
Documentation: cgroup-v2: fix path to example BPF program
docs: powerpc: Fix tables in syscall64-abi.rst
Documentation: features: refresh feature list
Documentation: features: remove c6x references
docs: ABI: testing: ima_policy: Fixed missing bracket
Fix unaesthetic indentation
scripts: kernel-doc: fix array element capture in pointer-to-func parsing
doc: use KCFLAGS instead of EXTRA_CFLAGS to pass flags from command line
Documentation: proc.rst: add more about the 6 fields in loadavg
Linus Torvalds [Fri, 26 Feb 2021 22:12:32 +0000 (14:12 -0800)]
Merge tag 's390-5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Vasily Gorbik:
- Fix physical vs virtual confusion in some basic mm macros and
routines. Caused by __pa == __va on s390 currently.
- Get rid of on-stack cpu masks.
- Add support for complete CPU counter set extraction.
- Add arch_irq_work_raise implementation.
- virtio-ccw revision and opcode fixes.
* tag 's390-5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cpumf: Add support for complete counter set extraction
virtio/s390: implement virtio-ccw revision 2 correctly
s390/smp: implement arch_irq_work_raise()
s390/topology: move cpumasks away from stack
s390/smp: smp_emergency_stop() - move cpumask away from stack
s390/smp: __smp_rescan_cpus() - move cpumask away from stack
s390/smp: consolidate locking for smp_rescan()
s390/mm: fix phys vs virt confusion in vmem_*() functions family
s390/mm: fix phys vs virt confusion in pgtable allocation routines
s390/mm: fix invalid __pa() usage in pfn_pXd() macros
s390/mm: make pXd_deref() macros return a pointer
s390/opcodes: rename selhhhr to selfhr
Linus Torvalds [Fri, 26 Feb 2021 22:09:41 +0000 (14:09 -0800)]
Merge tag '5.12-smb3-part1' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs updates from Steve French:
- improvements to mode bit conversion, chmod and chown when using
cifsacl mount option
- two new mount options for controlling attribute caching
- improvements to crediting and reconnect, improved debugging
- reconnect fix
- add SMB3.1.1 dialect to default dialects for vers=3
* tag '5.12-smb3-part1' of git://git.samba.org/sfrench/cifs-2.6: (27 commits)
cifs: update internal version number
cifs: use discard iterator to discard unneeded network data more efficiently
cifs: introduce helper for finding referral server to improve DFS target resolution
cifs: check all path components in resolved dfs target
cifs: fix DFS failover
cifs: fix nodfs mount option
cifs: fix handling of escaped ',' in the password mount argument
cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout
cifs: convert revalidate of directories to using directory metadata cache timeout
cifs: Add new mount parameter "acdirmax" to allow caching directory metadata
cifs: If a corrupted DACL is returned by the server, bail out.
cifs: minor simplification to smb2_is_network_name_deleted
TCON Reconnect during STATUS_NETWORK_NAME_DELETED
cifs: cleanup a few le16 vs. le32 uses in cifsacl.c
cifs: Change SIDs in ACEs while transferring file ownership.
cifs: Retain old ACEs when converting between mode bits and ACL.
cifs: Fix cifsacl ACE mask for group and others.
cifs: clarify hostname vs ip address in /proc/fs/cifs/DebugData
cifs: change confusing field serverName (to ip_addr)
cifs: Fix inconsistent IS_ERR and PTR_ERR
...
Linus Torvalds [Fri, 26 Feb 2021 22:07:12 +0000 (14:07 -0800)]
Merge tag 'for-5.12/io_uring-2021-02-25' of git://git.kernel.dk/linux-block
Pull more io_uring updates from Jens Axboe:
"A collection of later fixes that we should get into this release:
- Series of submission cleanups (Pavel)
- A few fixes for issues from earlier this merge window (Pavel, me)
- IOPOLL resubmission fix
- task_work locking fix (Hao)"
* tag 'for-5.12/io_uring-2021-02-25' of git://git.kernel.dk/linux-block: (25 commits)
Revert "io_uring: wait potential ->release() on resurrect"
io_uring: fix locked_free_list caches_free()
io_uring: don't attempt IO reissue from the ring exit path
io_uring: clear request count when freeing caches
io_uring: run task_work on io_uring_register()
io_uring: fix leaving invalid req->flags
io_uring: wait potential ->release() on resurrect
io_uring: keep generic rsrc infra generic
io_uring: zero ref_node after killing it
io_uring: make the !CONFIG_NET helpers a bit more robust
io_uring: don't hold uring_lock when calling io_run_task_work*
io_uring: fail io-wq submission from a task_work
io_uring: don't take uring_lock during iowq cancel
io_uring: fail links more in io_submit_sqe()
io_uring: don't do async setup for links' heads
io_uring: do io_*_prep() early in io_submit_sqe()
io_uring: split sqe-prep and async setup
io_uring: don't submit link on error
io_uring: move req link into submit_state
io_uring: move io_init_req() into io_submit_sqe()
...
Linus Torvalds [Fri, 26 Feb 2021 21:59:32 +0000 (13:59 -0800)]
Merge branch 'stable/for-linus-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb updates from Konrad Rzeszutek Wilk:
"Two memory encryption related patches (SWIOTLB is enabled by default
for AMD-SEV):
- Add support for alignment so that NVME can properly work
- Keep track of requested DMA buffers length, as underlaying hardware
devices can trip SWIOTLB to bounce too much and crash the kernel
And a tiny fix to use proper APIs in drivers"
* 'stable/for-linus-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Validate bounce size in the sync/unmap path
nvme-pci: set min_align_mask
swiotlb: respect min_align_mask
swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single
swiotlb: refactor swiotlb_tbl_map_single
swiotlb: clean up swiotlb_tbl_unmap_single
swiotlb: factor out a nr_slots helper
swiotlb: factor out an io_tlb_offset helper
swiotlb: add a IO_TLB_SIZE define
driver core: add a min_align_mask field to struct device_dma_parameters
sdhci: stop poking into swiotlb internals
Linus Torvalds [Fri, 26 Feb 2021 21:56:40 +0000 (13:56 -0800)]
Merge tag 'leds-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds
Pull LED updates from Pavel Machek:
"Besides the usual fixes and new drivers, we are changing CLASS_FLASH
to return success to make it easier to work with V4L2 stuff disabled,
and we are getting rid of enum that should have been plain integer
long time ago. I'm slightly nervous about potential warnings, but it
needed to be fixed at some point"
* tag 'leds-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds:
leds: lp50xx: Get rid of redundant explicit casting
leds: lp50xx: Update headers block to reflect reality
leds: lp50xx: Get rid of redundant check in lp50xx_enable_disable()
leds: lp50xx: Reduce level of dereferences
leds: lp50xx: Switch to new style i2c-driver probe function
leds: lp50xx: Don't spam logs when probe is deferred
leds: apu: extend support for PC Engines APU1 with newer firmware
leds: flash: Fix multicolor no-ops registration by return 0
leds: flash: Add flash registration with undefined CONFIG_LEDS_CLASS_FLASH
leds: lgm: Add LED controller driver for LGM SoC
dt-bindings: leds: Add bindings for Intel LGM SoC
leds: led-core: Get rid of enum led_brightness
leds: gpio: Set max brightness to 1
leds: lm3533: Switch to using the new API kobj_to_dev()
leds: ss4200: simplify the return expression of register_nasgpio_led()
leds: Use DEVICE_ATTR_{RW, RO, WO} macros
Linus Torvalds [Fri, 26 Feb 2021 18:28:35 +0000 (10:28 -0800)]
Merge tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
"A handful of new RISC-V related patches for this merge window:
- A check to ensure drivers are properly using uaccess. This isn't
manifesting with any of the drivers I'm currently using, but may
catch errors in new drivers.
- Some preliminary support for the FU740, along with the HiFive
Unleashed it will appear on.
- NUMA support for RISC-V, which involves making the arm64 code
generic.
- Support for kasan on the vmalloc region.
- A handful of new drivers for the Kendryte K210, along with the DT
plumbing required to boot on a handful of K210-based boards.
- Support for allocating ASIDs.
- Preliminary support for kernels larger than 128MiB.
- Various other improvements to our KASAN support, including the
utilization of huge pages when allocating the KASAN regions.
We may have already found a bug with the KASAN_VMALLOC code, but it's
passing my tests. There's a fix in the works, but that will probably
miss the merge window.
* tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (75 commits)
riscv: Improve kasan population by using hugepages when possible
riscv: Improve kasan population function
riscv: Use KASAN_SHADOW_INIT define for kasan memory initialization
riscv: Improve kasan definitions
riscv: Get rid of MAX_EARLY_MAPPING_SIZE
soc: canaan: Sort the Makefile alphabetically
riscv: Disable KSAN_SANITIZE for vDSO
riscv: Remove unnecessary declaration
riscv: Add Canaan Kendryte K210 SD card defconfig
riscv: Update Canaan Kendryte K210 defconfig
riscv: Add Kendryte KD233 board device tree
riscv: Add SiPeed MAIXDUINO board device tree
riscv: Add SiPeed MAIX GO board device tree
riscv: Add SiPeed MAIX DOCK board device tree
riscv: Add SiPeed MAIX BiT board device tree
riscv: Update Canaan Kendryte K210 device tree
dt-bindings: add resets property to dw-apb-timer
dt-bindings: fix sifive gpio properties
dt-bindings: update sifive uart compatible string
dt-bindings: update sifive clint compatible string
...
Linus Torvalds [Fri, 26 Feb 2021 18:19:03 +0000 (10:19 -0800)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"The big one is a fix for the VHE enabling path during early boot,
where the code enabling the MMU wasn't necessarily in the identity map
of the new page-tables, resulting in a consistent crash with 64k
pages. In fixing that, we noticed some missing barriers too, so we
added those for the sake of architectural compliance.
Other than that, just the usual merge window trickle. There'll be more
to come, too.
Summary:
- Fix lockdep false alarm on resume-from-cpuidle path
- Fix memory leak in kexec_file
- Fix module linker script to work with GDB
- Fix error code when trying to use uprobes with AArch32 instructions
- Fix late VHE enabling with 64k pages
- Add missing ISBs after TLB invalidation
- Fix seccomp when tracing syscall -1
- Fix stacktrace return code at end of stack
- Fix inconsistent whitespace for pointer return values
- Fix compiler warnings when building with W=1"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: stacktrace: Report when we reach the end of the stack
arm64: ptrace: Fix seccomp of traced syscall -1 (NO_SYSCALL)
arm64: Add missing ISB after invalidating TLB in enter_vhe
arm64: Add missing ISB after invalidating TLB in __primary_switch
arm64: VHE: Enable EL2 MMU from the idmap
KVM: arm64: make the hyp vector table entries local
arm64/mm: Fixed some coding style issues
arm64: uprobe: Return EOPNOTSUPP for AARCH32 instruction probing
kexec: move machine_kexec_post_load() to public interface
arm64 module: set plt* section addresses to 0x0
arm64: kexec_file: fix memory leakage in create_dtb() when fdt_open_into() fails
arm64: spectre: Prevent lockdep splat on v4 mitigation enable path
Linus Torvalds [Fri, 26 Feb 2021 18:14:18 +0000 (10:14 -0800)]
Merge tag 'trace-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two fixes:
- Fix an unsafe printf string usage in a kmem trace event
- Fix spelling in output from the latency-collector tool"
* tag 'trace-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/tools: fix a couple of spelling mistakes
mm, tracing: Fix kmem_cache_free trace event to not print stale pointers
Linus Torvalds [Fri, 26 Feb 2021 18:12:19 +0000 (10:12 -0800)]
Merge tag 'orphan-handling-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull orphan handling fix from Kees Cook:
"Another case of bogus .eh_frame emission was noticed under
CONFIG_GCOV_KERNEL=y.
Summary:
- Define SANITIZER_DISCARDS with CONFIG_GCOV_KERNEL=y (Nathan
Chancellor)"
* tag 'orphan-handling-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
vmlinux.lds.h: Define SANITIZER_DISCARDS with CONFIG_GCOV_KERNEL=y
Linus Torvalds [Fri, 26 Feb 2021 18:08:50 +0000 (10:08 -0800)]
Merge tag 'clang-lto-v5.12-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull clang LTO fixes from Kees Cook:
"This gets parisc building again and moves LTO artifact caching cleanup
from the 'distclean' build target to 'clean'.
Summary:
- Fix parisc build for ftrace vs mcount (Sami Tolvanen)
- Move .thinlto-cache remove to "clean" from "distclean" (Masahiro Yamada)"
* tag 'clang-lto-v5.12-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: Move .thinlto-cache removal to 'make clean'
parisc: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
Linus Torvalds [Fri, 26 Feb 2021 18:04:45 +0000 (10:04 -0800)]
Merge tag 'for-linus-5.12b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull more xen updates from Juergen Gross:
- A small series for Xen event channels adding some sysfs nodes for per
pv-device settings and statistics, and two fixes of theoretical
problems.
- two minor fixes (one for an unlikely error path, one for a comment).
* tag 'for-linus-5.12b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen-front-pgdir-shbuf: don't record wrong grant handle upon error
xen: Replace lkml.org links with lore
xen/evtchn: use READ/WRITE_ONCE() for accessing ring indices
xen/evtchn: use smp barriers for user event ring
xen/events: add per-xenbus device event statistics and settings
Linus Torvalds [Fri, 26 Feb 2021 18:00:12 +0000 (10:00 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more KVM updates from Paolo Bonzini:
"x86:
- take into account HVA before retrying on MMU notifier race
- fixes for nested AMD guests without NPT
- allow INVPCID in guest without PCID
- disable PML in hardware when not in use
- MMU code cleanups:
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
KVM: SVM: Fix nested VM-Exit on #GP interception handling
KVM: vmx/pmu: Fix dummy check if lbr_desc->event is created
KVM: x86/mmu: Consider the hva in mmu_notifier retry
KVM: x86/mmu: Skip mmu_notifier check when handling MMIO page fault
KVM: Documentation: rectify rst markup in KVM_GET_SUPPORTED_HV_CPUID
KVM: nSVM: prepare guest save area while is_guest_mode is true
KVM: x86/mmu: Remove a variety of unnecessary exports
KVM: x86: Fold "write-protect large" use case into generic write-protect
KVM: x86/mmu: Don't set dirty bits when disabling dirty logging w/ PML
KVM: VMX: Dynamically enable/disable PML based on memslot dirty logging
KVM: x86: Further clarify the logic and comments for toggling log dirty
KVM: x86: Move MMU's PML logic to common code
KVM: x86/mmu: Make dirty log size hook (PML) a value, not a function
KVM: x86/mmu: Expand on the comment in kvm_vcpu_ad_need_write_protect()
KVM: nVMX: Disable PML in hardware when running L2
KVM: x86/mmu: Consult max mapping level when zapping collapsible SPTEs
KVM: x86/mmu: Pass the memslot to the rmap callbacks
KVM: x86/mmu: Split out max mapping level calculation to helper
KVM: x86/mmu: Expand collapsible SPTE zap for TDP MMU to ZONE_DEVICE and HugeTLB pages
KVM: nVMX: no need to undo inject_page_fault change on nested vmexit
...
Linus Torvalds [Fri, 26 Feb 2021 17:50:09 +0000 (09:50 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
"118 patches:
- The rest of MM.
Includes kfence - another runtime memory validator. Not as thorough
as KASAN, but it has unmeasurable overhead and is intended to be
usable in production builds.
- Everything else
Subsystems affected by this patch series: alpha, procfs, sysctl,
misc, core-kernel, MAINTAINERS, lib, bitops, checkpatch, init,
coredump, seq_file, gdb, ubsan, initramfs, and mm (thp, cma,
vmstat, memory-hotplug, mlock, rmap, zswap, zsmalloc, cleanups,
kfence, kasan2, and pagemap2)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
MIPS: make userspace mapping young by default
initramfs: panic with memory information
ubsan: remove overflow checks
kgdb: fix to kill breakpoints on initmem after boot
scripts/gdb: fix list_for_each
x86: fix seq_file iteration for pat/memtype.c
seq_file: document how per-entry resources are managed.
fs/coredump: use kmap_local_page()
init/Kconfig: fix a typo in CC_VERSION_TEXT help text
init: clean up early_param_on_off() macro
init/version.c: remove Version_<LINUX_VERSION_CODE> symbol
checkpatch: do not apply "initialise globals to 0" check to BPF progs
checkpatch: don't warn about colon termination in linker scripts
checkpatch: add kmalloc_array_node to unnecessary OOM message check
checkpatch: add warning for avoiding .L prefix symbols in assembly files
checkpatch: improve TYPECAST_INT_CONSTANT test message
checkpatch: prefer ftrace over function entry/exit printks
checkpatch: trivial style fixes
checkpatch: ignore warning designated initializers using NR_CPUS
checkpatch: improve blank line after declaration test
...
Huang Pei [Fri, 26 Feb 2021 01:22:49 +0000 (17:22 -0800)]
MIPS: make userspace mapping young by default
MIPS page fault path(except huge page) takes 3 exceptions (1 TLB Miss + 2
TLB Invalid), butthe second TLB Invalid exception is just triggered by
__update_tlb from do_page_fault writing tlb without _PAGE_VALID set. With
this patch, user space mapping prot is made young by default (with both
_PAGE_VALID and _PAGE_YOUNG set), and it only take 1 TLB Miss + 1 TLB
Invalid exception
Remove pte_sw_mkyoung without polluting MM code and make page fault delay
of MIPS on par with other architecture
Link: https://lkml.kernel.org/r/20210204013942.8398-1-huangpei@loongson.cn Signed-off-by: Huang Pei <huangpei@loongson.cn> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: <huangpei@loongson.cn> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: <ambrosehua@gmail.com> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Paul Burton <paulburton@kernel.org> Cc: Li Xuefeng <lixuefeng@loongson.cn> Cc: Yang Tiezhu <yangtiezhu@loongson.cn> Cc: Gao Juxin <gaojuxin@loongson.cn> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Huacai Chen <chenhc@lemote.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Florian Fainelli [Fri, 26 Feb 2021 01:22:46 +0000 (17:22 -0800)]
initramfs: panic with memory information
On systems with large amounts of reserved memory we may fail to
successfully complete unpack_to_rootfs() and be left with:
Kernel panic - not syncing: write error
this is not too helpful to understand what happened, so let's wrap the
panic() calls with a surrounding show_mem() such that we have a chance of
understanding the memory conditions leading to these allocation failures.
[akpm@linux-foundation.org: replace macro with C function]
Andrey Ryabinin [Fri, 26 Feb 2021 01:22:42 +0000 (17:22 -0800)]
ubsan: remove overflow checks
Since GCC 8.0 -fsanitize=signed-integer-overflow doesn't work with
-fwrapv. -fwrapv makes signed overflows defines and GCC essentially
disables ubsan checks. On GCC < 8.0 -fwrapv doesn't have influence on
-fsanitize=signed-integer-overflow setting, so it kinda works but
generates false-positves and violates uaccess rules:
lib/iov_iter.o: warning: objtool: iovec_from_user()+0x22d: call to
__ubsan_handle_add_overflow() with UACCESS enabled
Disable signed overflow checks to avoid these problems. Remove unsigned
overflow checks as well. Unsigned overflow appeared as side effect of
commit 9e274aaf27b7 ("ubsan: move cc-option tests into Kconfig"), but it
never worked (kernel doesn't boot). And unsigned overflows are allowed by
C standard, so it just pointless.
Link: https://lkml.kernel.org/r/20210209232348.20510-1-ryabinin.a.a@gmail.com Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sumit Garg [Fri, 26 Feb 2021 01:22:38 +0000 (17:22 -0800)]
kgdb: fix to kill breakpoints on initmem after boot
Currently breakpoints in kernel .init.text section are not handled
correctly while allowing to remove them even after corresponding pages
have been freed.
Fix it via killing .init.text section breakpoints just prior to initmem
pages being freed.
Doug: "HW breakpoints aren't handled by this patch but it's probably
not such a big deal".
Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Suggested-by: Doug Anderson <dianders@chromium.org> Acked-by: Doug Anderson <dianders@chromium.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NeilBrown [Fri, 26 Feb 2021 01:22:29 +0000 (17:22 -0800)]
x86: fix seq_file iteration for pat/memtype.c
The memtype seq_file iterator allocates a buffer in the ->start and ->next
functions and frees it in the ->show function. The preferred handling for
such resources is to free them in the subsequent ->next or ->stop function
call.
Since Commit 46cb04d471b6 ("fs/seq_file.c: simplify seq_file iteration
code and interface") there is no guarantee that ->show will be called
after ->next, so this function can now leak memory.
So move the freeing of the buffer to ->next and ->stop.
Link: https://lkml.kernel.org/r/161248539022.21478.13874455485854739066.stgit@noble1 Fixes: 46cb04d471b6 ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: NeilBrown <neilb@suse.de> Cc: Xin Long <lucien.xin@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NeilBrown [Fri, 26 Feb 2021 01:22:25 +0000 (17:22 -0800)]
seq_file: document how per-entry resources are managed.
Patch series "Fix some seq_file users that were recently broken".
A recent change to seq_file broke some users which were using seq_file
in a non-"standard" way ... though the "standard" isn't documented, so
they can be excused. The result is a possible leak - of memory in one
case, of references to a 'transport' in the other.
These three patches:
1/ document and explain the problem
2/ fix the problem user in x86
3/ fix the problem user in net/sctp
This patch (of 3):
Users of seq_file will sometimes find it convenient to take a resource,
such as a lock or memory allocation, in the ->start or ->next operations.
These are per-entry resources, distinct from per-session resources which
are taken in ->start and released in ->stop.
The preferred management of these is release the resource on the
subsequent call to ->next or ->stop.
However prior to Commit 46cb04d471b6 ("fs/seq_file.c: simplify seq_file
iteration code and interface") it happened that ->show would always be
called after ->start or ->next, and a few users chose to release the
resource in ->show.
This is no longer reliable. Since the mentioned commit, ->next will
always come after a successful ->show (to ensure m->index is updated
correctly), so the original ordering cannot be maintained.
This patch updates the documentation to clearly state the required
behaviour. Other patches will fix the few problematic users.
[akpm@linux-foundation.org: fix typo, per Willy]
Link: https://lkml.kernel.org/r/161248518659.21478.2484341937387294998.stgit@noble1 Link: https://lkml.kernel.org/r/161248539020.21478.3147971477400875336.stgit@noble1 Fixes: 46cb04d471b6 ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: NeilBrown <neilb@suse.de> Cc: Xin Long <lucien.xin@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Masahiro Yamada [Fri, 26 Feb 2021 01:22:11 +0000 (17:22 -0800)]
init/version.c: remove Version_<LINUX_VERSION_CODE> symbol
This code hunk creates a Version_<LINUX_VERSION_CODE> symbol if
CONFIG_KALLSYMS is disabled. For example, building the kernel v5.10 for
allnoconfig creates the following symbol:
$ nm vmlinux | grep Version_ c116b028 B Version_330240
There is no in-tree user of this symbol.
Commit d855aa497569 ("init/version.c: define version_string only if
CONFIG_KALLSYMS is not defined") mentions that Version_* is only used
with ksymoops.
However, a commit in the pre-git era [1] had added the statement,
"ksymoops is useless on 2.6. Please use the Oops in its original format".
That statement existed until commit 67cf7c4c63fc ("Documentation:
admin-guide: update bug-hunting.rst") finally removed the stale
ksymoops information.
Song Liu [Fri, 26 Feb 2021 01:22:08 +0000 (17:22 -0800)]
checkpatch: do not apply "initialise globals to 0" check to BPF progs
BPF programs explicitly initialise global variables to 0 to make sure
clang (v10 or older) do not put the variables in the common section. Skip
"initialise globals to 0" check for BPF programs to elimiate error
messages like:
ERROR: do not initialise globals to 0
#19: FILE: samples/bpf/tracex1_kern.c:21:
Link: https://lkml.kernel.org/r/20210209211954.490077-1-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chris Down [Fri, 26 Feb 2021 01:22:04 +0000 (17:22 -0800)]
checkpatch: don't warn about colon termination in linker scripts
This check erroneously flags cases like the one in my recent printk
enumeration patch[0], where the spaces are syntactic, and `section:' vs.
`section :' is syntactically important:
ERROR: space prohibited before that ':' (ctx:WxW)
#258: FILE: include/asm-generic/vmlinux.lds.h:314:
+ .printk_fmts : AT(ADDR(.printk_fmts) - LOAD_OFFSET) {
Joe Perches [Fri, 26 Feb 2021 01:22:01 +0000 (17:22 -0800)]
checkpatch: add kmalloc_array_node to unnecessary OOM message check
commit a5820ac7e61d ("include/linux/slab.h: add kmalloc_array_node() and
kcalloc_node()") was added in 2017. Update the unnecessary OOM message
test to include it.
checkpatch: add warning for avoiding .L prefix symbols in assembly files
objtool requires that all code must be contained in an ELF symbol. Symbol
names that have a '.L' prefix do not emit symbol table entries, as they
have special meaning for the assembler.
'.L' prefixed symbols can be used within a code region, but should be
avoided for denoting a range of code via 'SYM_*_START/END' annotations.
Add a new check to emit a warning on finding the usage of '.L' symbols for
'.S' files, if it denotes range of code via SYM_*_START/END annotation
pair.
Link: https://lkml.kernel.org/r/20210123190459.9701-1-yashsri421@gmail.com Link: https://lore.kernel.org/lkml/20210112210154.GI4646@sirena.org.uk Signed-off-by: Aditya Srivastava <yashsri421@gmail.com> Suggested-by: Mark Brown <broonie@kernel.org> Acked-by: Joe Perches <joe@perches.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Aditya Srivastava <yashsri421@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Dwaipayan Ray <dwaipayanray1@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Fri, 26 Feb 2021 01:21:40 +0000 (17:21 -0800)]
checkpatch: improve blank line after declaration test
Avoid multiple false positives by ignoring attributes.
Various attributes like volatile and ____cacheline_aligned_in_smp cause
checkpatch to emit invalid "Missing a blank line after declarations"
messages.
Use copies of $sline and $prevline, remove $Attribute and $Sparse, and use
the existing tests to avoid these false positives.
Miscellanea:
o Add volatile to $Attribute
This also reduces checkpatch runtime a bit by moving the indentation
comparison test to the start of the block to avoid multiple unnecessary
regex tests.
Vijayanand Jitta [Fri, 26 Feb 2021 01:21:31 +0000 (17:21 -0800)]
lib: stackdepot: fix ignoring return value warning
Fix the below ignoring return value warning for kstrtobool in
is_stack_depot_disabled function.
lib/stackdepot.c: In function 'is_stack_depot_disabled':
lib/stackdepot.c:154:2: warning: ignoring return value of 'kstrtobool'
declared with attribute 'warn_unused_result' [-Wunused-result]
Link: https://lkml.kernel.org/r/1612163048-28026-1-git-send-email-vjitta@codeaurora.org Fixes: b9779abb09a8 ("lib: stackdepot: add support to disable stack depot") Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vijayanand Jitta [Fri, 26 Feb 2021 01:21:27 +0000 (17:21 -0800)]
lib: stackdepot: add support to disable stack depot
Add a kernel parameter stack_depot_disable to disable stack depot. So
that stack hash table doesn't consume any memory when stack depot is
disabled.
The use case is CONFIG_PAGE_OWNER without page_owner=on. Without this
patch, stackdepot will consume the memory for the hashtable. By default,
it's 8M which is never trivial.
With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off,
stack_depot_disable in kernel command line, we could save the wasted
memory for the hashtable.
Yogesh Lal [Fri, 26 Feb 2021 01:21:24 +0000 (17:21 -0800)]
lib: stackdepot: add support to configure STACK_HASH_SIZE
Use CONFIG_STACK_HASH_ORDER to configure STACK_HASH_SIZE.
Aim is to have configurable value for STACK_HASH_SIZE,
so depend on use case one can configure it.
One example is of Page Owner, CONFIG_PAGE_OWNER works only if
page_owner=on via kernel parameter on CONFIG_PAGE_OWNER configured system.
Thus, unless admin enable it via command line option, the stackdepot will
just waste 8M memory without any customer.
Making it configurable and use lower value helps to enable features like
CONFIG_PAGE_OWNER without any significant overhead.
Link: https://lkml.kernel.org/r/1611749198-24316-1-git-send-email-vjitta@codeaurora.org Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Francis Laniel [Fri, 26 Feb 2021 01:21:20 +0000 (17:21 -0800)]
string.h: move fortified functions definitions in a dedicated header.
This patch adds fortify-string.h to contain fortified functions
definitions. Thus, the code is more separated and compile time is
approximately 1% faster for people who do not set CONFIG_FORTIFY_SOURCE.
Vlastimil Babka [Fri, 26 Feb 2021 01:21:14 +0000 (17:21 -0800)]
MAINTAINERS: add uapi directories to API/ABI section
Let's add include/uapi/ and arch/*/include/uapi/ to API/ABI section, so
that for patches modifying them, get_maintainers.pl suggests CCing
linux-api@ so people don't forget.
Link: https://lkml.kernel.org/r/20210217174745.13591-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: David Hildenbrand <david@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Fri, 26 Feb 2021 01:20:56 +0000 (17:20 -0800)]
include/linux: remove repeated words
Drop the doubled word "for" in a comment. {firewire-cdev.h}
Drop the doubled word "in" in a comment. {input.h}
Drop the doubled word "a" in a comment. {mdev.h}
Drop the doubled word "the" in a comment. {ptrace.h}
Link: https://lkml.kernel.org/r/20210126232444.22861-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kirti Wankhede <kwankhede@nvidia.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lin Feng [Fri, 26 Feb 2021 01:20:53 +0000 (17:20 -0800)]
sysctl.c: fix underflow value setting risk in vm_table
Apart from subsystem specific .proc_handler handler, all ctl_tables with
extra1 and extra2 members set should use proc_dointvec_minmax instead of
proc_dointvec, or the limit set in extra* never work and potentially echo
underflow values(negative numbers) is likely make system unstable.
Especially vfs_cache_pressure and zone_reclaim_mode, -1 is apparently not
a valid value, but we can set to them. And then kernel may crash.
# echo -1 > /proc/sys/vm/vfs_cache_pressure
Link: https://lkml.kernel.org/r/20201223105535.2875-1-linf@wangsu.com Signed-off-by: Lin Feng <linf@wangsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josef Bacik [Fri, 26 Feb 2021 01:20:49 +0000 (17:20 -0800)]
proc: use kvzalloc for our kernel buffer
Since
sysctl: pass kernel pointers to ->proc_handler
we have been pre-allocating a buffer to copy the data from the proc
handlers into, and then copying that to userspace. The problem is this
just blindly kzalloc()'s the buffer size passed in from the read, which in
the case of our 'cat' binary was 64kib. Order-4 allocations are not
awesome, and since we can potentially allocate up to our maximum order, so
use kvzalloc for these buffers.
[willy@infradead.org: changelog tweaks]
Link: https://lkml.kernel.org/r/6345270a2c1160b89dd5e6715461f388176899d1.1612972413.git.josef@toxicpanda.com Fixes: ecad013df758 ("sysctl: pass kernel pointers to ->proc_handler") Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> CC: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Helge Deller [Fri, 26 Feb 2021 01:20:45 +0000 (17:20 -0800)]
proc/wchan: use printk format instead of lookup_symbol_name()
To resolve the symbol fuction name for wchan, use the printk format
specifier %ps instead of manually looking up the symbol function name
via lookup_symbol_name().
Andrey Konovalov [Fri, 26 Feb 2021 01:20:31 +0000 (17:20 -0800)]
arm64: kasan: simplify and inline MTE functions
This change provides a simpler implementation of mte_get_mem_tag(),
mte_get_random_tag(), and mte_set_mem_tag_range().
Simplifications include removing system_supports_mte() checks as these
functions are onlye called from KASAN runtime that had already checked
system_supports_mte(). Besides that, size and address alignment checks
are removed from mte_set_mem_tag_range(), as KASAN now does those.
This change also moves these functions into the asm/mte-kasan.h header and
implements mte_set_mem_tag_range() via inline assembly to avoid
unnecessary functions calls.
[vincenzo.frascino@arm.com: fix warning in mte_get_random_tag()] Link: https://lkml.kernel.org/r/20210211152208.23811-1-vincenzo.frascino@arm.com Link: https://lkml.kernel.org/r/a26121b294fdf76e369cb7a74351d1c03a908930.1612546384.git.andreyknvl@google.com Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:27 +0000 (17:20 -0800)]
kasan: ensure poisoning size alignment
A previous changes 690763d1f845 ("kasan: don't round_up too much")
attempted to simplify the code by adding a round_up(size) call into
kasan_poison(). While this allows to have less round_up() calls around
the code, this results in round_up() being called multiple times.
This patch removes round_up() of size from kasan_poison() and ensures that
all callers round_up() the size explicitly. This patch also adds
WARN_ON() alignment checks for address and size to kasan_poison() and
kasan_unpoison().
Link: https://lkml.kernel.org/r/3ffe8d4a246ae67a8b5e91f65bf98cd7cba9d7b9.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:23 +0000 (17:20 -0800)]
kasan, mm: optimize krealloc poisoning
Currently, krealloc() always calls ksize(), which unpoisons the whole
object including the redzone. This is inefficient, as kasan_krealloc()
repoisons the redzone for objects that fit into the same buffer.
This patch changes krealloc() instrumentation to use uninstrumented
__ksize() that doesn't unpoison the memory. Instead, kasan_kreallos() is
changed to unpoison the memory excluding the redzone.
For objects that don't fit into the old allocation, this patch disables
KASAN accessibility checks when copying memory into a new object instead
of unpoisoning it.
Link: https://lkml.kernel.org/r/9bef90327c9cb109d736c40115684fd32f49e6b0.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:19 +0000 (17:20 -0800)]
kasan, mm: fail krealloc on freed objects
Currently, if krealloc() is called on a freed object with KASAN enabled,
it allocates and returns a new object, but doesn't copy any memory from
the old one as ksize() returns 0. This makes the caller believe that
krealloc() succeeded (KASAN report is printed though).
This patch adds an accessibility check into __do_krealloc(). If the check
fails, krealloc() returns NULL. This check duplicates the one in ksize();
this is fixed in the following patch.
This patch also adds a KASAN-KUnit test to check krealloc() behaviour when
it's called on a freed object.
Link: https://lkml.kernel.org/r/cbcf7b02be0a1ca11de4f833f2ff0b3f2c9b00c8.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:15 +0000 (17:20 -0800)]
kasan: rework krealloc tests
This patch reworks KASAN-KUnit tests for krealloc() to:
1. Check both slab and page_alloc based krealloc() implementations.
2. Allow at least one full granule to fit between old and new sizes for
each KASAN mode, and check accesses to that granule accordingly.
Link: https://lkml.kernel.org/r/c707f128a2bb9f2f05185d1eb52192cf179cf4fa.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:07 +0000 (17:20 -0800)]
kasan: clean up setting free info in kasan_slab_free
Put kasan_stack_collection_enabled() check and kasan_set_free_info() calls
next to each other.
The way this was previously implemented was a minor optimization that
relied of the the fact that kasan_stack_collection_enabled() is always
true for generic KASAN. The confusion that this brings outweights saving
a few instructions.
Link: https://lkml.kernel.org/r/f838e249be5ab5810bf54a36ef5072cfd80e2da7.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:03 +0000 (17:20 -0800)]
kasan: optimize large kmalloc poisoning
Similarly to kasan_kmalloc(), kasan_kmalloc_large() doesn't need to
unpoison the object as it as already unpoisoned by alloc_pages() (or by
ksize() for krealloc()).
This patch changes kasan_kmalloc_large() to only poison the redzone.
Link: https://lkml.kernel.org/r/33dee5aac0e550ad7f8e26f590c9b02c6129b4a3.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:19:59 +0000 (17:19 -0800)]
kasan, mm: optimize kmalloc poisoning
For allocations from kmalloc caches, kasan_kmalloc() always follows
kasan_slab_alloc(). Currenly, both of them unpoison the whole object,
which is unnecessary.
This patch provides separate implementations for both annotations:
kasan_slab_alloc() unpoisons the whole object, and kasan_kmalloc() only
poisons the redzone.
For generic KASAN, the redzone start might not be aligned to
KASAN_GRANULE_SIZE. Therefore, the poisoning is split in two parts:
kasan_poison_last_granule() poisons the unaligned part, and then
kasan_poison() poisons the rest.
This patch also clarifies alignment guarantees of each of the poisoning
functions and drops the unnecessary round_up() call for redzone_end.
With this change, the early SLUB cache annotation needs to be changed to
kasan_slab_alloc(), as kasan_kmalloc() doesn't unpoison objects now. The
number of poisoned bytes for objects in this cache stays the same, as
kmem_cache_node->object_size is equal to sizeof(struct kmem_cache_node).
Link: https://lkml.kernel.org/r/7e3961cb52be380bc412860332063f5f7ce10d13.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:19:55 +0000 (17:19 -0800)]
kasan, mm: don't save alloc stacks twice
Patch series "kasan: optimizations and fixes for HW_TAGS", v4.
This patchset makes the HW_TAGS mode more efficient, mostly by reworking
poisoning approaches and simplifying/inlining some internal helpers.
With this change, the overhead of HW_TAGS annotations excluding setting
and checking memory tags is ~3%. The performance impact caused by tags
will be unknown until we have hardware that supports MTE.
As a side-effect, this patchset speeds up generic KASAN by ~15%.
This patch (of 13):
Currently KASAN saves allocation stacks in both kasan_slab_alloc() and
kasan_kmalloc() annotations. This patch changes KASAN to save allocation
stacks for slab objects from kmalloc caches in kasan_kmalloc() only, and
stacks for other slab objects in kasan_slab_alloc() only.
This change requires ____kasan_kmalloc() knowing whether the object
belongs to a kmalloc cache. This is implemented by adding a flag field to
the kasan_info structure. That flag is only set for kmalloc caches via a
new kasan_cache_create_kmalloc() annotation.
Link: https://lkml.kernel.org/r/cover.1612546384.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/7c673ebca8d00f40a7ad6f04ab9a2bddeeae2097.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make it possible to trace KASAN error reporting. A good usecase is
watching for trace events from the userspace to detect and process memory
corruption reports from the kernel.
Link: https://lkml.kernel.org/r/20210121131915.1331302-4-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make it possible to trace KFENCE error reporting. A good usecase is
watching for trace events from the userspace to detect and process memory
corruption reports from the kernel.
Link: https://lkml.kernel.org/r/20210121131915.1331302-3-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Add error_report_end tracepoint to KFENCE and KASAN", v3.
This patchset adds a tracepoint, error_repor_end, that is to be used by
KFENCE, KASAN, and potentially other bug detection tools, when they print
an error report. One of the possible use cases is userspace collection of
kernel error reports: interested parties can subscribe to the tracing
event via tracefs, and get notified when an error report occurs.
This patch (of 3):
Introduce error_report_end tracepoint. It can be used in debugging tools
like KASAN, KFENCE, etc. to provide extensions to the error reporting
mechanisms (e.g. allow tests hook into error reporting, ease error report
collection from production kernels). Another benefit would be making use
of ftrace for debugging or benchmarking the tools themselves.
Should we need it, the tracepoint name leaves us with the possibility to
introduce a complementary error_report_start tracepoint in the future.
Marco Elver [Fri, 26 Feb 2021 01:19:40 +0000 (17:19 -0800)]
kfence: report sensitive information based on no_hash_pointers
We cannot rely on CONFIG_DEBUG_KERNEL to decide if we're running a "debug
kernel" where we can safely show potentially sensitive information in the
kernel log.
Instead, simply rely on the newly introduced "no_hash_pointers" to print
unhashed kernel pointers, as well as decide if our reports can include
other potentially sensitive information such as registers and corrupted
bytes.
Link: https://lkml.kernel.org/r/20210223082043.1972742-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Cc: Timur Tabi <timur@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:31 +0000 (17:19 -0800)]
kfence: add test suite
Add KFENCE test suite, testing various error detection scenarios. Makes
use of KUnit for test organization. Since KFENCE's interface to obtain
error reports is via the console, the test verifies that KFENCE outputs
expected reports to the console.
[elver@google.com: fix typo in test] Link: https://lkml.kernel.org/r/X9lHQExmHGvETxY4@elver.google.com
[elver@google.com: show access type in report] Link: https://lkml.kernel.org/r/20210111091544.3287013-2-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-9-elver@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Alexander Potapenko <glider@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make KFENCE compatible with KASAN. Currently this helps test KFENCE
itself, where KASAN can catch potential corruptions to KFENCE state, or
other corruptions that may be a result of freepointer corruptions in the
main allocators.
[akpm@linux-foundation.org: merge fixup]
[andreyknvl@google.com: untag addresses for KFENCE] Link: https://lkml.kernel.org/r/9dc196006921b191d25d10f6e611316db7da2efc.1611946152.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-7-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jann Horn <jannh@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To pass the originally requested size to KFENCE, add an argument
'orig_size' to slab_alloc*(). The additional argument is required to
preserve the requested original size for kmalloc() allocations, which
uses size classes (e.g. an allocation of 272 bytes will return an object
of size 512). Therefore, kmem_cache::size does not represent the
kmalloc-caller's requested size, and we must introduce the argument
'orig_size' to propagate the originally requested size to KFENCE.
Without the originally requested size, we would not be able to detect
out-of-bounds accesses for objects placed at the end of a KFENCE object
page if that object is not equal to the kmalloc-size class it was
bucketed into.
When KFENCE is disabled, there is no additional overhead, since
slab_alloc*() functions are __always_inline.
Link: https://lkml.kernel.org/r/20201103175841.3495947-6-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jann Horn <jannh@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To pass the originally requested size to KFENCE, add an argument
'orig_size' to slab_alloc*(). The additional argument is required to
preserve the requested original size for kmalloc() allocations, which
uses size classes (e.g. an allocation of 272 bytes will return an object
of size 512). Therefore, kmem_cache::size does not represent the
kmalloc-caller's requested size, and we must introduce the argument
'orig_size' to propagate the originally requested size to KFENCE.
Without the originally requested size, we would not be able to detect
out-of-bounds accesses for objects placed at the end of a KFENCE object
page if that object is not equal to the kmalloc-size class it was
bucketed into.
When KFENCE is disabled, there is no additional overhead, since
slab_alloc*() functions are __always_inline.
Link: https://lkml.kernel.org/r/20201103175841.3495947-5-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Marco Elver <elver@google.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: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:08 +0000 (17:19 -0800)]
kfence: use pt_regs to generate stack trace on faults
Instead of removing the fault handling portion of the stack trace based on
the fault handler's name, just use struct pt_regs directly.
Change kfence_handle_page_fault() to take a struct pt_regs, and plumb it
through to kfence_report_error() for out-of-bounds, use-after-free, or
invalid access errors, where pt_regs is used to generate the stack trace.
If the kernel is a DEBUG_KERNEL, also show registers for more information.
Link: https://lkml.kernel.org/r/20201105092133.2075331-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:03 +0000 (17:19 -0800)]
arm64, kfence: enable KFENCE for ARM64
Add architecture specific implementation details for KFENCE and enable
KFENCE for the arm64 architecture. In particular, this implements the
required interface in <asm/kfence.h>.
KFENCE requires that attributes for pages from its memory pool can
individually be set. Therefore, force the entire linear map to be mapped
at page granularity. Doing so may result in extra memory allocated for
page tables in case rodata=full is not set; however, currently
CONFIG_RODATA_FULL_DEFAULT_ENABLED=y is the default, and the common case
is therefore not affected by this change.
[elver@google.com: add missing copyright and description header] Link: https://lkml.kernel.org/r/20210118092159.145934-3-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-4-elver@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Alexander Potapenko <glider@google.com> Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add architecture specific implementation details for KFENCE and enable
KFENCE for the x86 architecture. In particular, this implements the
required interface in <asm/kfence.h> for setting up the pool and
providing helper functions for protecting and unprotecting pages.
For x86, we need to ensure that the pool uses 4K pages, which is done
using the set_memory_4k() helper function.
[elver@google.com: add missing copyright and description header] Link: https://lkml.kernel.org/r/20210118092159.145934-2-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-3-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Marco Elver <elver@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7.
This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors. This
series enables KFENCE for the x86 and arm64 architectures, and adds
KFENCE hooks to the SLAB and SLUB allocators.
KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.
KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error.
Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval,
the next allocation through the main allocator (SLAB or SLUB) returns a
guarded allocation from the KFENCE object pool. At this point, the timer
is reset, and the next allocation is set up after the expiration of the
interval.
To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE.
The KFENCE memory pool is of fixed size, and if the pool is exhausted no
further KFENCE allocations occur. The default config is conservative
with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB
pages).
We have verified by running synthetic benchmarks (sysbench I/O,
hackbench) and production server-workload benchmarks that a kernel with
KFENCE (using sample intervals 100-500ms) is performance-neutral
compared to a non-KFENCE baseline kernel.
KFENCE is inspired by GWP-ASan [1], a userspace tool with similar
properties. The name "KFENCE" is a homage to the Electric Fence Malloc
Debugger [2].
For more details, see Documentation/dev-tools/kfence.rst added in the
series -- also viewable here:
This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors.
KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.
KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error. To detect out-of-bounds
writes to memory within the object's page itself, KFENCE also uses
pattern-based redzones. The following figure illustrates the page
layout:
---+-----------+-----------+-----------+-----------+-----------+---
| xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx |
| xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx |
| x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x |
| xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx |
| xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx |
| xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx |
---+-----------+-----------+-----------+-----------+-----------+---
Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval, a
guarded allocation from the KFENCE object pool is returned to the main
allocator (SLAB or SLUB). At this point, the timer is reset, and the
next allocation is set up after the expiration of the interval.
To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE. To date, we have verified by running synthetic
benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE
is performance-neutral compared to the non-KFENCE baseline.
For more details, see Documentation/dev-tools/kfence.rst (added later in
the series).
[elver@google.com: fix parameter description for kfence_object_start()] Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com
[elver@google.com: avoid stalling work queue task without allocations] Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com
[elver@google.com: fix potential deadlock due to wake_up()] Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com
[elver@google.com: add option to use KFENCE without static keys] Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com
[elver@google.com: add missing copyright and description headers] Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: SeongJae Park <sjpark@amazon.de> Co-developed-by: Marco Elver <elver@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Joern Engel <joern@purestorage.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guo Ren [Fri, 26 Feb 2021 01:18:38 +0000 (17:18 -0800)]
mm: page-flags.h: Typo fix (It -> If)
The "If" was wrongly spelled as "It".
Link: https://lkml.kernel.org/r/1608959036-91409-1-git-send-email-guoren@kernel.org Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Steven Price <steven.price@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rokudo Yan [Fri, 26 Feb 2021 01:18:31 +0000 (17:18 -0800)]
zsmalloc: account the number of compacted pages correctly
There exists multiple path may do zram compaction concurrently.
1. auto-compaction triggered during memory reclaim
2. userspace utils write zram<id>/compaction node
So, multiple threads may call zs_shrinker_scan/zs_compact concurrently.
But pages_compacted is a per zsmalloc pool variable and modification
of the variable is not serialized(through under class->lock).
There are two issues here:
1. the pages_compacted may not equal to total number of pages
freed(due to concurrently add).
2. zs_shrinker_scan may not return the correct number of pages
freed(issued by current shrinker).
The fix is simple:
1. account the number of pages freed in zs_compact locally.
2. use actomic variable pages_compacted to accumulate total number.
Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com Fixes: d71ab675fb21fe56 ("zsmalloc: account the number of compacted pages") Signed-off-by: Rokudo Yan <wu-yan@tcl.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:27 +0000 (17:18 -0800)]
mm/zsmalloc.c: convert to use kmem_cache_zalloc in cache_alloc_zspage()
We always memset the zspage allocated via cache_alloc_zspage. So it's
more convenient to use kmem_cache_zalloc in cache_alloc_zspage than caller
do it manually.
Link: https://lkml.kernel.org/r/20210114120032.25885-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tian Tao [Fri, 26 Feb 2021 01:18:22 +0000 (17:18 -0800)]
mm: set the sleep_mapped to true for zbud and z3fold
zpool driver adds a flag to indicate whether the zpool driver can enter an
atomic context after mapping. This patch sets it true for z3fold and
zbud.
Link: https://lkml.kernel.org/r/1611035683-12732-3-git-send-email-tiantao6@hisilicon.com Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Mike Galbraith <efault@gmx.de> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tian Tao [Fri, 26 Feb 2021 01:18:17 +0000 (17:18 -0800)]
mm/zswap: add the flag can_sleep_mapped
Patch series "Fix the compatibility of zsmalloc and zswap".
Patch #1 adds a flag to zpool, then zswap used to determine if zpool
drivers such as zbud/z3fold/zsmalloc will enter an atomic context after
mapping.
The difference between zbud/z3fold and zsmalloc is that zsmalloc requires
an atomic context that since its map function holds a preempt-disabled,
but zbud/z3fold don't require an atomic context. So patch #2 sets flag
sleep_mapped to true indicating that zbud/z3fold can sleep after mapping.
zsmalloc didn't support sleep after mapping, so don't set that flag to
true.
This patch (of 2):
Add a flag to zpool, named is "can_sleep_mapped", and have it set true for
zbud/z3fold, not set this flag for zsmalloc, so its default value is
false. Then zswap could go the current path if the flag is true; and if
it's false, copy data from src to a temporary buffer, then unmap the
handle, take the mutex, process the buffer instead of src to avoid
sleeping function called from atomic context.
Miaohe Lin [Fri, 26 Feb 2021 01:18:09 +0000 (17:18 -0800)]
mm/rmap: fix potential pte_unmap on an not mapped pte
For PMD-mapped page (usually THP), pvmw->pte is NULL. For PTE-mapped THP,
pvmw->pte is mapped. But for HugeTLB pages, pvmw->pte is not mapped and
set to the relevant page table entry. So in page_vma_mapped_walk_done(),
we may do pte_unmap() for HugeTLB pte which is not mapped. Fix this by
checking pvmw->page against PageHuge before trying to do pte_unmap().
Link: https://lkml.kernel.org/r/20210127093349.39081-1-linmiaohe@huawei.com Fixes: db7b6349d502 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hongxiang Lou <louhongxiang@huawei.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michel Lespinasse <walken@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:06 +0000 (17:18 -0800)]
mm/rmap: correct obsolete comment of page_get_anon_vma()
Since commit 300b793ea708 ("mm: use refcounts for page_lock_anon_vma()"),
page_lock_anon_vma() is renamed to page_get_anon_vma() and converted to
return a refcount increased anon_vma. But it forgot to change the
relevant comment.
Link: https://lkml.kernel.org/r/20210203093215.31990-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:03 +0000 (17:18 -0800)]
mm/rmap: use page_not_mapped in try_to_unmap()
page_mapcount_is_zero() calculates accurately how many mappings a hugepage
has in order to check against 0 only. This is a waste of cpu time. We
can do this via page_not_mapped() to save some possible atomic_read
cycles. Remove the function page_mapcount_is_zero() as it's not used
anymore and move page_not_mapped() above try_to_unmap() to avoid
identifier undeclared compilation error.
Miaohe Lin [Fri, 26 Feb 2021 01:17:59 +0000 (17:17 -0800)]
mm/rmap: fix obsolete comment in __page_check_anon_rmap()
Commit 56b192ae5cca ("ksm: no debug in page_dup_rmap()") has reverted
page_dup_rmap() to an inline atomic_inc of mapcount. So page_dup_rmap()
does not call __page_check_anon_rmap() anymore.
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