linux-stable.git/drivers/char, branch v6.0.2

random: use expired timer rather than wq for mixing fast pool

2022-10-15T06:02:57+00:00

commit 748bc4dd9e663f23448d8ad7e58c011a67ea1eca upstream.

Previously, the fast pool was dumped into the main pool periodically in
the fast pool's hard IRQ handler. This worked fine and there weren't
problems with it, until RT came around. Since RT converts spinlocks into
sleeping locks, problems cropped up. Rather than switching to raw
spinlocks, the RT developers preferred we make the transformation from
originally doing:

    do_some_stuff()
    spin_lock()
    do_some_other_stuff()
    spin_unlock()

to doing:

    do_some_stuff()
    queue_work_on(some_other_stuff_worker)

This is an ordinary pattern done all over the kernel. However, Sherry
noticed a 10% performance regression in qperf TCP over a 40gbps
InfiniBand card. Quoting her message:

> MT27500 Family [ConnectX-3] cards:
> Infiniband device 'mlx4_0' port 1 status:
> default gid: fe80:0000:0000:0000:0010:e000:0178:9eb1
> base lid: 0x6
> sm lid: 0x1
> state: 4: ACTIVE
> phys state: 5: LinkUp
> rate: 40 Gb/sec (4X QDR)
> link_layer: InfiniBand
>
> Cards are configured with IP addresses on private subnet for IPoIB
> performance testing.
> Regression identified in this bug is in TCP latency in this stack as reported
> by qperf tcp_lat metric:
>
> We have one system listen as a qperf server:
> [root@yourQperfServer ~]# qperf
>
> Have the other system connect to qperf server as a client (in this
> case, it’s X7 server with Mellanox card):
> [root@yourQperfClient ~]# numactl -m0 -N0 qperf 20.20.20.101 -v -uu -ub --time 60 --wait_server 20 -oo msg_size:4K:1024K:*2 tcp_lat

Rather than incur the scheduling latency from queue_work_on, we can
instead switch to running on the next timer tick, on the same core. This
also batches things a bit more -- once per jiffy -- which is okay now
that mix_interrupt_randomness() can credit multiple bits at once.

Reported-by: Sherry Yang 
Tested-by: Paul Webb 
Cc: Sherry Yang 
Cc: Phillip Goerl 
Cc: Jack Vogel 
Cc: Nicky Veitch 
Cc: Colm Harrington 
Cc: Ramanan Govindarajan 
Cc: Sebastian Andrzej Siewior 
Cc: Dominik Brodowski 
Cc: Tejun Heo 
Cc: Sultan Alsawaf 
Cc: stable@vger.kernel.org
Fixes: 58340f8e952b ("random: defer fast pool mixing to worker")
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

random: avoid reading two cache lines on irq randomness

2022-10-15T06:02:57+00:00

commit 9ee0507e896b45af6d65408c77815800bce30008 upstream.

In order to avoid reading and dirtying two cache lines on every IRQ,
move the work_struct to the bottom of the fast_pool struct. add_
interrupt_randomness() always touches .pool and .count, which are
currently split, because .mix pushes everything down. Instead, move .mix
to the bottom, so that .pool and .count are always in the first cache
line, since .mix is only accessed when the pool is full.

Fixes: 58340f8e952b ("random: defer fast pool mixing to worker")
Reviewed-by: Sebastian Andrzej Siewior 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

random: clamp credited irq bits to maximum mixed

2022-10-15T06:02:55+00:00

commit e78a802a7b4febf53f2a92842f494b01062d85a8 upstream.

Since the most that's mixed into the pool is sizeof(long)*2, don't
credit more than that many bytes of entropy.

Fixes: e3e33fc2ea7f ("random: do not use input pool from hard IRQs")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

random: restore O_NONBLOCK support

2022-10-15T06:02:55+00:00

commit cd4f24ae9404fd31fc461066e57889be3b68641b upstream.

Prior to 5.6, when /dev/random was opened with O_NONBLOCK, it would
return -EAGAIN if there was no entropy. When the pools were unified in
5.6, this was lost. The post 5.6 behavior of blocking until the pool is
initialized, and ignoring O_NONBLOCK in the process, went unnoticed,
with no reports about the regression received for two and a half years.
However, eventually this indeed did break somebody's userspace.

So we restore the old behavior, by returning -EAGAIN if the pool is not
initialized. Unlike the old /dev/random, this can only occur during
early boot, after which it never blocks again.

In order to make this O_NONBLOCK behavior consistent with other
expectations, also respect users reading with preadv2(RWF_NOWAIT) and
similar.

Fixes: 30c08efec888 ("random: make /dev/random be almost like /dev/urandom")
Reported-by: Guozihua 
Reported-by: Zhongguohua 
Cc: Al Viro 
Cc: Theodore Ts'o 
Cc: Andrew Lutomirski 
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

/dev/null: add IORING_OP_URING_CMD support

2022-08-26T15:19:44+00:00

This patch adds support for the io_uring command pass through, aka
IORING_OP_URING_CMD, to the /dev/null driver.  As with all of the
/dev/null functionality, the implementation is just a simple sink
where commands go to die, but it should be useful for developers who
need a simple IORING_OP_URING_CMD test device that doesn't require
any special hardware.

Cc: Arnd Bergmann 
Cc: Greg Kroah-Hartman 
Acked-by: Jens Axboe 
Signed-off-by: Paul Moore

Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2022-08-07T00:05:21+00:00

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

   This includes a few prerequisite updates and fixes to the oldmem
   reading code.

 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities, but
   also allows CPU facilities.

 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.

 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.

 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
   test.

 - Fix incorrect recovery of kretprobe modified return address in
   stacktrace.

 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.

 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as
   well as to implement more of the AP architecture.

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  Revert "s390/smp: enforce lowcore protection on CPU restart"
  Revert "s390/smp: rework absolute lowcore access"
  Revert "s390/smp,ptdump: add absolute lowcore markers"
  s390/unwind: fix fgraph return address recovery
  s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
  s390: add ELF note type for encrypted CPU state of a PV VCPU
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/setup: rearrange absolute lowcore initialization
  s390/boot: cleanup adjust_to_uv_max() function
  s390/smp: enforce lowcore protection on CPU restart
  s390/tape: fix comment typo
  s390/hmcdrv: fix Kconfig "its" grammar
  s390/docs: fix warnings for vfio_ap driver doc
  s390/docs: fix warnings for vfio_ap driver lock usage doc
  s390/crash: support multi-segment iterators
  s390/crash: use static swap buffer for copy_to_user_real()
  s390/crash: move copy_to_user_real() to crash_dump.c
  s390/zcore: fix race when reading from hardware system area
  s390/crash: fix incorrect number of bytes to copy to user space
  ...

Merge tag 'powerpc-6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-08-06T23:38:17+00:00

Pull powerpc updates from Michael Ellerman:

 - Add support for syscall stack randomization

 - Add support for atomic operations to the 32 & 64-bit BPF JIT

 - Full support for KASAN on 64-bit Book3E

 - Add a watchdog driver for the new PowerVM hypervisor watchdog

 - Add a number of new selftests for the Power10 PMU support

 - Add a driver for the PowerVM Platform KeyStore

 - Increase the NMI watchdog timeout during live partition migration, to
   avoid timeouts due to increased memory access latency

 - Add support for using the 'linux,pci-domain' device tree property for
   PCI domain assignment

 - Many other small features and fixes

Thanks to Alexey Kardashevskiy, Andy Shevchenko, Arnd Bergmann, Athira
Rajeev, Bagas Sanjaya, Christophe Leroy, Erhard Furtner, Fabiano Rosas,
Greg Kroah-Hartman, Greg Kurz, Haowen Bai, Hari Bathini, Jason A.
Donenfeld, Jason Wang, Jiang Jian, Joel Stanley, Juerg Haefliger, Kajol
Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Masahiro Yamada,
Maxime Bizon, Miaoqian Lin, Murilo Opsfelder Araújo, Nathan Lynch,
Naveen N.  Rao, Nayna Jain, Nicholas Piggin, Ning Qiang, Pali Rohár,
Petr Mladek, Rashmica Gupta, Sachin Sant, Scott Cheloha, Segher
Boessenkool, Stephen Rothwell, Uwe Kleine-König, Wolfram Sang, Xiu
Jianfeng, and Zhouyi Zhou.

* tag 'powerpc-6.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (191 commits)
  powerpc/64e: Fix kexec build error
  EDAC/ppc_4xx: Include required of_irq header directly
  powerpc/pci: Fix PHB numbering when using opal-phbid
  powerpc/64: Init jump labels before parse_early_param()
  selftests/powerpc: Avoid GCC 12 uninitialised variable warning
  powerpc/cell/axon_msi: Fix refcount leak in setup_msi_msg_address
  powerpc/xive: Fix refcount leak in xive_get_max_prio
  powerpc/spufs: Fix refcount leak in spufs_init_isolated_loader
  powerpc/perf: Include caps feature for power10 DD1 version
  powerpc: add support for syscall stack randomization
  powerpc: Move system_call_exception() to syscall.c
  powerpc/powernv: rename remaining rng powernv_ functions to pnv_
  powerpc/powernv/kvm: Use darn for H_RANDOM on Power9
  powerpc/powernv: Avoid crashing if rng is NULL
  selftests/powerpc: Fix matrix multiply assist test
  powerpc/signal: Update comment for clarity
  powerpc: make facility_unavailable_exception 64s
  powerpc/platforms/83xx/suspend: Remove write-only global variable
  powerpc/platforms/83xx/suspend: Prevent unloading the driver
  powerpc/platforms/83xx/suspend: Reorder to get rid of a forward declaration
  ...

Merge tag 'iommu-updates-v5.20-or-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2022-08-06T17:42:38+00:00

Pull iommu updates from Joerg Roedel:

 - The most intrusive patch is small and changes the default allocation
   policy for DMA addresses.

   Before the change the allocator tried its best to find an address in
   the first 4GB. But that lead to performance problems when that space
   gets exhaused, and since most devices are capable of 64-bit DMA these
   days, we changed it to search in the full DMA-mask range from the
   beginning.

   This change has the potential to uncover bugs elsewhere, in the
   kernel or the hardware. There is a Kconfig option and a command line
   option to restore the old behavior, but none of them is enabled by
   default.

 - Add Robin Murphy as reviewer of IOMMU code and maintainer for the
   dma-iommu and iova code

 - Chaning IOVA magazine size from 1032 to 1024 bytes to save memory

 - Some core code cleanups and dead-code removal

 - Support for ACPI IORT RMR node

 - Support for multiple PCI domains in the AMD-Vi driver

 - ARM SMMU changes from Will Deacon:
      - Add even more Qualcomm device-tree compatible strings
      - Support dumping of IMP DEF Qualcomm registers on TLB sync
        timeout
      - Fix reference count leak on device tree node in Qualcomm driver

 - Intel VT-d driver updates from Lu Baolu:
      - Make intel-iommu.h private
      - Optimize the use of two locks
      - Extend the driver to support large-scale platforms
      - Cleanup some dead code

 - MediaTek IOMMU refactoring and support for TTBR up to 35bit

 - Basic support for Exynos SysMMU v7

 - VirtIO IOMMU driver gets a map/unmap_pages() implementation

 - Other smaller cleanups and fixes

* tag 'iommu-updates-v5.20-or-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (116 commits)
  iommu/amd: Fix compile warning in init code
  iommu/amd: Add support for AVIC when SNP is enabled
  iommu/amd: Simplify and Consolidate Virtual APIC (AVIC) Enablement
  ACPI/IORT: Fix build error implicit-function-declaration
  drivers: iommu: fix clang -wformat warning
  iommu/arm-smmu: qcom_iommu: Add of_node_put() when breaking out of loop
  iommu/arm-smmu-qcom: Add SM6375 SMMU compatible
  dt-bindings: arm-smmu: Add compatible for Qualcomm SM6375
  MAINTAINERS: Add Robin Murphy as IOMMU SUBSYTEM reviewer
  iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled
  iommu/amd: Do not support IOMMU_DOMAIN_IDENTITY after SNP is enabled
  iommu/amd: Set translation valid bit only when IO page tables are in use
  iommu/amd: Introduce function to check and enable SNP
  iommu/amd: Globally detect SNP support
  iommu/amd: Process all IVHDs before enabling IOMMU features
  iommu/amd: Introduce global variable for storing common EFR and EFR2
  iommu/amd: Introduce Support for Extended Feature 2 Register
  iommu/amd: Change macro for IOMMU control register bit shift to decimal value
  iommu/exynos: Enable default VM instance on SysMMU v7
  iommu/exynos: Add SysMMU v7 register set
  ...

Merge tag 'tpmdd-next-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

2022-08-06T16:43:02+00:00

Pull tpm updates from Jarkko Sakkinen:
 "Mostly TPM and also few keyring fixes"

* tag 'tpmdd-next-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  tpm: Add check for Failure mode for TPM2 modules
  tpm: eventlog: Fix section mismatch for DEBUG_SECTION_MISMATCH
  tpm: fix platform_no_drv_owner.cocci warning
  KEYS: asymmetric: enforce SM2 signature use pkey algo
  pkcs7: support EC-RDSA/streebog in SignerInfo
  pkcs7: parser support SM2 and SM3 algorithms combination
  sign-file: Fix confusing error messages
  X.509: Support parsing certificate using SM2 algorithm
  tpm: Add tpm_tis_i2c backend for tpm_tis_core
  tpm: Add tpm_tis_verify_crc to the tpm_tis_phy_ops protocol layer
  dt-bindings: trivial-devices: Add Infineon SLB9673 TPM
  tpm: Add upgrade/reduced mode support for TPM1.2 modules

Merge tag 'spdx-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

2022-08-04T19:12:54+00:00

Pull SPDX updates from Greg KH:
 "Here is the set of SPDX comment updates for 6.0-rc1.

  Nothing huge here, just a number of updated SPDX license tags and
  cleanups based on the review of a number of common patterns in GPLv2
  boilerplate text.

  Also included in here are a few other minor updates, two USB files,
  and one Documentation file update to get the SPDX lines correct.

  All of these have been in the linux-next tree for a very long time"

* tag 'spdx-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (28 commits)
  Documentation: samsung-s3c24xx: Add blank line after SPDX directive
  x86/crypto: Remove stray comment terminator
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_406.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_398.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_391.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_390.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_385.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_320.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_319.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_318.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_298.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_292.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_179.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 2)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 1)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_160.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_152.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_149.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_147.RULE
  treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_133.RULE
  ...