Pull IOMMU updates from Will Deacon:
"There's a good mixture of improvements to the core code and driver
changes across the board.
One thing worth pointing out is that this includes a quirk to work
around behaviour in the i915 driver (see 65f746e828 ("iommu: Add
quirk for Intel graphic devices in map_sg")), which otherwise
interacts badly with the conversion of the intel IOMMU driver over to
the DMA-IOMMU APU but has being fixed properly in the DRM tree.
We'll revert the quirk later this cycle once we've confirmed that
things don't fall apart without it.
Summary:
- IOVA allocation optimisations and removal of unused code
- Introduction of DOMAIN_ATTR_IO_PGTABLE_CFG for parameterising the
page-table of an IOMMU domain
- Support for changing the default domain type in sysfs
- Optimisation to the way in which identity-mapped regions are
created
- Driver updates:
* Arm SMMU updates, including continued work on Shared Virtual
Memory
* Tegra SMMU updates, including support for PCI devices
* Intel VT-D updates, including conversion to the IOMMU-DMA API
- Cleanup, kerneldoc and minor refactoring"
* tag 'iommu-updates-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (50 commits)
iommu/amd: Add sanity check for interrupt remapping table length macros
dma-iommu: remove __iommu_dma_mmap
iommu/io-pgtable: Remove tlb_flush_leaf
iommu: Stop exporting free_iova_mem()
iommu: Stop exporting alloc_iova_mem()
iommu: Delete split_and_remove_iova()
iommu/io-pgtable-arm: Remove unused 'level' parameter from iopte_type() macro
iommu: Defer the early return in arm_(v7s/lpae)_map
iommu: Improve the performance for direct_mapping
iommu: avoid taking iova_rbtree_lock twice
iommu/vt-d: Avoid GFP_ATOMIC where it is not needed
iommu/vt-d: Remove set but not used variable
iommu: return error code when it can't get group
iommu: Fix htmldocs warnings in sysfs-kernel-iommu_groups
iommu: arm-smmu-impl: Add a space before open parenthesis
iommu: arm-smmu-impl: Use table to list QCOM implementations
iommu/arm-smmu: Move non-strict mode to use io_pgtable_domain_attr
iommu/arm-smmu: Add support for pagetable config domain attribute
iommu: Document usage of "/sys/kernel/iommu_groups/<grp_id>/type" file
iommu: Take lock before reading iommu group default domain type
...
Pull pstore updates from Kees Cook:
- Clean up unused but exposed API (Christoph Hellwig)
- Provide KCONFIG for default size of kmsg buffer (Vasile-Laurentiu
Stanimir)
* tag 'pstore-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
pstore: Move kmsg_bytes default into Kconfig
pstore/blk: remove {un,}register_pstore_blk
pstore/blk: update the command line example
pstore/zone: cap the maximum device size
Merge more updates from Andrew Morton:
"More MM work: a memcg scalability improvememt"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/lru: revise the comments of lru_lock
mm/lru: introduce relock_page_lruvec()
mm/lru: replace pgdat lru_lock with lruvec lock
mm/swap.c: serialize memcg changes in pagevec_lru_move_fn
mm/compaction: do page isolation first in compaction
mm/lru: introduce TestClearPageLRU()
mm/mlock: remove __munlock_isolate_lru_page()
mm/mlock: remove lru_lock on TestClearPageMlocked
mm/vmscan: remove lruvec reget in move_pages_to_lru
mm/lru: move lock into lru_note_cost
mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn
mm/memcg: add debug checking in lock_page_memcg
mm: page_idle_get_page() does not need lru_lock
mm/rmap: stop store reordering issue on page->mapping
mm/vmscan: remove unnecessary lruvec adding
mm/thp: narrow lru locking
mm/thp: simplify lru_add_page_tail()
mm/thp: use head for head page in lru_add_page_tail()
mm/thp: move lru_add_page_tail() to huge_memory.c
Pull char / misc driver updates from Greg KH:
"Here is the big char/misc driver update for 5.11-rc1.
Continuing the tradition of previous -rc1 pulls, there seems to be
more and more tiny driver subsystems flowing through this tree.
Lots of different things, all of which have been in linux-next for a
while with no reported issues:
- extcon driver updates
- habannalab driver updates
- mei driver updates
- uio driver updates
- binder fixes and features added
- soundwire driver updates
- mhi bus driver updates
- phy driver updates
- coresight driver updates
- fpga driver updates
- speakup driver updates
- slimbus driver updates
- various small char and misc driver updates"
* tag 'char-misc-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (305 commits)
extcon: max77693: Fix modalias string
extcon: fsa9480: Support TI TSU6111 variant
extcon: fsa9480: Rewrite bindings in YAML and extend
dt-bindings: extcon: add binding for TUSB320
extcon: Add driver for TI TUSB320
slimbus: qcom: fix potential NULL dereference in qcom_slim_prg_slew()
siox: Make remove callback return void
siox: Use bus_type functions for probe, remove and shutdown
spmi: Add driver shutdown support
spmi: fix some coding style issues at the spmi core
spmi: get rid of a warning when built with W=1
uio: uio_hv_generic: use devm_kzalloc() for private data alloc
uio: uio_fsl_elbc_gpcm: use device-managed allocators
uio: uio_aec: use devm_kzalloc() for uio_info object
uio: uio_cif: use devm_kzalloc() for uio_info object
uio: uio_netx: use devm_kzalloc() for or uio_info object
uio: uio_mf624: use devm_kzalloc() for uio_info object
uio: uio_sercos3: use device-managed functions for simple allocs
uio: uio_dmem_genirq: finalize conversion of probe to devm_ handlers
uio: uio_dmem_genirq: convert simple allocations to device-managed
...
Pull USB / Thunderbolt updates from Greg KH:
"Here is the big USB and thunderbolt pull request for 5.11-rc1.
Nothing major in here, just the grind of constant development to
support new hardware and fix old issues:
- thunderbolt updates for new USB4 hardware
- cdns3 major driver updates
- lots of typec updates and additions as more hardware is available
- usb serial driver updates and fixes
- other tiny USB driver updates
All have been in linux-next with no reported issues"
* tag 'usb-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (172 commits)
usb: phy: convert comma to semicolon
usb: ucsi: convert comma to semicolon
usb: typec: tcpm: convert comma to semicolon
usb: typec: tcpm: Update vbus_vsafe0v on init
usb: typec: tcpci: Enable bleed discharge when auto discharge is enabled
usb: typec: Add class for plug alt mode device
USB: typec: tcpci: Add Bleed discharge to POWER_CONTROL definition
USB: typec: tcpm: Add a 30ms room for tPSSourceOn in PR_SWAP
USB: typec: tcpm: Fix PR_SWAP error handling
USB: typec: tcpm: Hard Reset after not receiving a Request
USB: gadget: f_fs: remove likely/unlikely
usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus
USB: gadget: f_midi: setup SuperSpeed Plus descriptors
USB: gadget: f_acm: add support for SuperSpeed Plus
USB: gadget: f_rndis: fix bitrate for SuperSpeed and above
usb: typec: intel_pmc_mux: Configure cable generation value for USB4
MAINTAINERS: Add myself as a reviewer for CADENCE USB3 DRD IP DRIVER
usb: chipidea: ci_hdrc_imx: Use of_device_get_match_data()
usb: chipidea: usbmisc_imx: Use of_device_get_match_data()
usb: cdns3: fix NULL pointer dereference on no platform data
...
Pull networking updates from Jakub Kicinski:
"Core:
- support "prefer busy polling" NAPI operation mode, where we defer
softirq for some time expecting applications to periodically busy
poll
- AF_XDP: improve efficiency by more batching and hindering the
adjacency cache prefetcher
- af_packet: make packet_fanout.arr size configurable up to 64K
- tcp: optimize TCP zero copy receive in presence of partial or
unaligned reads making zero copy a performance win for much smaller
messages
- XDP: add bulk APIs for returning / freeing frames
- sched: support fragmenting IP packets as they come out of conntrack
- net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs
BPF:
- BPF switch from crude rlimit-based to memcg-based memory accounting
- BPF type format information for kernel modules and related tracing
enhancements
- BPF implement task local storage for BPF LSM
- allow the FENTRY/FEXIT/RAW_TP tracing programs to use
bpf_sk_storage
Protocols:
- mptcp: improve multiple xmit streams support, memory accounting and
many smaller improvements
- TLS: support CHACHA20-POLY1305 cipher
- seg6: add support for SRv6 End.DT4/DT6 behavior
- sctp: Implement RFC 6951: UDP Encapsulation of SCTP
- ppp_generic: add ability to bridge channels directly
- bridge: Connectivity Fault Management (CFM) support as is defined
in IEEE 802.1Q section 12.14.
Drivers:
- mlx5: make use of the new auxiliary bus to organize the driver
internals
- mlx5: more accurate port TX timestamping support
- mlxsw:
- improve the efficiency of offloaded next hop updates by using
the new nexthop object API
- support blackhole nexthops
- support IEEE 802.1ad (Q-in-Q) bridging
- rtw88: major bluetooth co-existance improvements
- iwlwifi: support new 6 GHz frequency band
- ath11k: Fast Initial Link Setup (FILS)
- mt7915: dual band concurrent (DBDC) support
- net: ipa: add basic support for IPA v4.5
Refactor:
- a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
Siewior
- phy: add support for shared interrupts; get rid of multiple driver
APIs and have the drivers write a full IRQ handler, slight growth
of driver code should be compensated by the simpler API which also
allows shared IRQs
- add common code for handling netdev per-cpu counters
- move TX packet re-allocation from Ethernet switch tag drivers to a
central place
- improve efficiency and rename nla_strlcpy
- number of W=1 warning cleanups as we now catch those in a patchwork
build bot
Old code removal:
- wan: delete the DLCI / SDLA drivers
- wimax: move to staging
- wifi: remove old WDS wifi bridging support"
* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
net: hns3: fix expression that is currently always true
net: fix proc_fs init handling in af_packet and tls
nfc: pn533: convert comma to semicolon
af_vsock: Assign the vsock transport considering the vsock address flags
af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
vsock_addr: Check for supported flag values
vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
vm_sockets: Add flags field in the vsock address data structure
net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
nfc: s3fwrn5: Release the nfc firmware
net: vxget: clean up sparse warnings
mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
mlxsw: reg: Add Router LPM Cache Enable Register
mlxsw: reg: Add Router LPM Cache ML Delete Register
mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
mlxsw: reg: Add XM Router M Table Register
...
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
For many workloads, pagetable consumption is significant and it makes
sense to expose it in the memory.stat for the memory cgroups. However at
the moment, the pagetables are accounted per-zone. Converting them to
per-node and using the right interface will correctly account for the
memory cgroups as well.
[akpm@linux-foundation.org: export __mod_lruvec_page_state to modules for arch/mips/kvm/]
Link: https://lkml.kernel.org/r/20201130212541.2781790-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull core entry/exit updates from Thomas Gleixner:
"A set of updates for entry/exit handling:
- More generalization of entry/exit functionality
- The consolidation work to reclaim TIF flags on x86 and also for
non-x86 specific TIF flags which are solely relevant for syscall
related work and have been moved into their own storage space. The
x86 specific part had to be merged in to avoid a major conflict.
- The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal
delivery mode of task work and results in an impressive performance
improvement for io_uring. The non-x86 consolidation of this is
going to come seperate via Jens.
- The selective syscall redirection facility which provides a clean
and efficient way to support the non-Linux syscalls of WINE by
catching them at syscall entry and redirecting them to the user
space emulation. This can be utilized for other purposes as well
and has been designed carefully to avoid overhead for the regular
fastpath. This includes the core changes and the x86 support code.
- Simplification of the context tracking entry/exit handling for the
users of the generic entry code which guarantee the proper ordering
and protection.
- Preparatory changes to make the generic entry code accomodate S390
specific requirements which are mostly related to their syscall
restart mechanism"
* tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
entry: Add syscall_exit_to_user_mode_work()
entry: Add exit_to_user_mode() wrapper
entry_Add_enter_from_user_mode_wrapper
entry: Rename exit_to_user_mode()
entry: Rename enter_from_user_mode()
docs: Document Syscall User Dispatch
selftests: Add benchmark for syscall user dispatch
selftests: Add kselftest for syscall user dispatch
entry: Support Syscall User Dispatch on common syscall entry
kernel: Implement selective syscall userspace redirection
signal: Expose SYS_USER_DISPATCH si_code type
x86: vdso: Expose sigreturn address on vdso to the kernel
MAINTAINERS: Add entry for common entry code
entry: Fix boot for !CONFIG_GENERIC_ENTRY
x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK
context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs
sched: Detect call to schedule from critical entry code
context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK
context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK
x86: Reclaim unused x86 TI flags
...
Pull documentation updates from Jonathan Corbet:
"A much quieter cycle for documentation (happily), with, one hopes, the
bulk of the churn behind us. Significant stuff in this pull includes:
- A set of new Chinese translations
- Italian translation updates
- A mechanism from Mauro to automatically format
Documentation/features for the built docs
- Automatic cross references without explicit :ref: markup
- A new reset-controller document
- An extensive new document on reporting problems from Thorsten
That last patch also adds the CC-BY-4.0 license to LICENSES/dual;
there was some discussion on this, but we seem to have consensus and
an ack from Greg for that addition"
* tag 'docs-5.11' of git://git.lwn.net/linux: (50 commits)
docs: fix broken cross reference in translations/zh_CN
docs: Note that sphinx 1.7 will be required soon
docs: update requirements to install six module
docs: reporting-issues: move 'outdated, need help' note to proper place
docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means
docs: add a reset controller chapter to the driver API docs
docs: make reporting-bugs.rst obsolete
docs: Add a new text describing how to report bugs
LICENSES: Add the CC-BY-4.0 license
Documentation: fix multiple typos found in the admin-guide subdirectory
Documentation: fix typos found in admin-guide subdirectory
kernel-doc: Fix example in Nested structs/unions
docs: clean up sysctl/kernel: titles, version
docs: trace: fix event state structure name
docs: nios2: add missing ReST file
scripts: get_feat.pl: reduce table width for all features output
scripts: get_feat.pl: change the group by order
scripts: get_feat.pl: make complete table more coincise
scripts: kernel-doc: fix parsing function-like typedefs
Documentation: fix typos found in process, dev-tools, and doc-guide subdirectories
...
Pull x86 SGC support from Borislav Petkov:
"Intel Software Guard eXtensions enablement. This has been long in the
making, we were one revision number short of 42. :)
Intel SGX is new hardware functionality that can be used by
applications to populate protected regions of user code and data
called enclaves. Once activated, the new hardware protects enclave
code and data from outside access and modification.
Enclaves provide a place to store secrets and process data with those
secrets. SGX has been used, for example, to decrypt video without
exposing the decryption keys to nosy debuggers that might be used to
subvert DRM. Software has generally been rewritten specifically to run
in enclaves, but there are also projects that try to run limited
unmodified software in enclaves.
Most of the functionality is concentrated into arch/x86/kernel/cpu/sgx/
except the addition of a new mprotect() hook to control enclave page
permissions and support for vDSO exceptions fixup which will is used
by SGX enclaves.
All this work by Sean Christopherson, Jarkko Sakkinen and many others"
* tag 'x86_sgx_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
x86/sgx: Return -EINVAL on a zero length buffer in sgx_ioc_enclave_add_pages()
x86/sgx: Fix a typo in kernel-doc markup
x86/sgx: Fix sgx_ioc_enclave_provision() kernel-doc comment
x86/sgx: Return -ERESTARTSYS in sgx_ioc_enclave_add_pages()
selftests/sgx: Use a statically generated 3072-bit RSA key
x86/sgx: Clarify 'laundry_list' locking
x86/sgx: Update MAINTAINERS
Documentation/x86: Document SGX kernel architecture
x86/sgx: Add ptrace() support for the SGX driver
x86/sgx: Add a page reclaimer
selftests/x86: Add a selftest for SGX
x86/vdso: Implement a vDSO for Intel SGX enclave call
x86/traps: Attempt to fixup exceptions in vDSO before signaling
x86/fault: Add a helper function to sanitize error code
x86/vdso: Add support for exception fixup in vDSO functions
x86/sgx: Add SGX_IOC_ENCLAVE_PROVISION
x86/sgx: Add SGX_IOC_ENCLAVE_INIT
x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES
x86/sgx: Add SGX_IOC_ENCLAVE_CREATE
x86/sgx: Add an SGX misc driver interface
...
Pull media updates from Mauro Carvalho Chehab:
- some rework at the uAPI pixel format docs
- the smiapp driver has started to gain support for MIPI CSS camera
sensors and was renamed
- two new sensor drivers: ov02a10 and ov9734
- Meson gained a driver for the 2D acceleration unit
- Rockchip rkisp1 driver was promoted from staging
- Cedrus driver gained support for VP8
- two new remote controller keymaps were added
- the usual set of fixes cleanups and driver improvements
* tag 'media/v5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (447 commits)
media: ccs: Add support for obtaining C-PHY configuration from firmware
media: ccs-pll: Print pixel rates
media: ccs: Print written register values
media: ccs: Add support for DDR OP SYS and OP PIX clocks
media: ccs-pll: Add support for DDR OP system and pixel clocks
media: ccs: Dual PLL support
media: ccs-pll: Add trivial dual PLL support
media: ccs-pll: Separate VT divisor limit calculation from the rest
media: ccs-pll: Fix VT post-PLL divisor calculation
media: ccs-pll: Make VT divisors 16-bit
media: ccs-pll: Rework bounds checks
media: ccs-pll: Print relevant information on PLL tree
media: ccs-pll: Better separate OP and VT sub-tree calculation
media: ccs-pll: Check for derating and overrating, support non-derating sensors
media: ccs-pll: Split off VT subtree calculation
media: ccs-pll: Add C-PHY support
media: ccs-pll: Add sanity checks
media: ccs-pll: Add support flexible OP PLL pixel clock divider
media: ccs-pll: Support two cycles per pixel on OP domain
media: ccs-pll: Add support for extended input PLL clock divider
...
Here's a patch updating the meaning of TAINT_CPU_OUT_OF_SPEC after
Borislav introduced changes in a7e1f67ed2 and upcoming patches in tip.
TAINT_CPU_OUT_OF_SPEC now means a bit more what it implies as the
flag isn't set just because of a CPU misconfiguration or mismatch.
Historically it was for SMP kernel oops on an officially SMP incapable
processor but now it also covers CPUs whose MSRs have been incorrectly
poked at from userspace, drivers being used on non supported
architectures, broken firmware, mismatched CPUs, ...
Update documentation and script to reflect that.
Signed-off-by: Mathieu Chouquet-Stringer <me@mathieu.digital>
Link: https://lore.kernel.org/r/20201202153244.709752-1-me@mathieu.digital
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Make various places which point to
Documentation/admin-guide/reporting-bugs.rst point to
Documentation/admin-guide/reporting-issues.rst instead. That document is
brand new and as of now is not completely finished. But even at this
stage it's a lot more helpful and accurate than reporting-bugs.rst.
Hence also add a note to reporting-bugs.rst, telling people they're
better off reading reporting-issues.rst instead.
reporting-bugs.rst is scheduled for removal once reporting-issues.rst
is considered ready.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/3df7c2d16de112b47bb6e6158138608e78562bf5.1607063223.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add a mostly finished document describing how to report issues with the
Linux kernel to its developers. It is designed to be a lot more straight
forward and easier to follow than the current text about this
(Documentation/admin-guide/reporting-bugs.rst); at the same time the new
text should be more helpful for people unfamiliar with the topic, as it
provides a lot more details, too.
The main work on the text is done, but some polishing is still needed.
The text also needs to be reviewed by more people and a few issues still
might need some discussion. To make these tasks easier, it was decided
([1]) to add this document to the kernel sources in parallel to the
existing text; the latter will be removed once this text is considered
good enough(tm).
This document is quite long and provides a lot of details, but was
carefully crafted to make sure it's can also serve people that are in a
hurry. That's mainly achieved by having a TDLR and a step-by-step guide,
which should be good enough for quite a lot of people. Everybody that
wants or need more explanations can find them in a reference section,
which describes all the needed steps in detail.
Thanks to this structure the text can work for kernel developers that
just need to look something up, experienced FLOSS contributors that are
unfamiliar with the kernel's bug reporting workflow, and users reporting
something upstream for the first time. The text is thus a bit like the
kernel itself, which works well for embedded machines, a typical desktop
PC, cloud servers, and HPC.
The document was written in the hope it will improve the quality of the
bug reports, especially those that come from people unfamiliar with how
Linux kernel development works. Sadly quite a few reports from this
group are currently of poor quality and/or get submitted to the wrong
place. Part of the problem is the old reporting-bugs document, as it
makes its essence hard to grasp; it's and also inaccurate and slightly
outdated in a few spots. Due to this quite a few valid reports are
ignored in the end, which is annoying for those that compiled them and
bad for the kernel's quality.
The document near the top points out that it's still unfinished, but
nevertheless ready for consumption. Those few areas in the text that
might need some further discussion contain a note pointing this out.
Besides lack of review from core developers there is only one major
issue left: the section 'Decode failure message' is known to be
outdated: it's waiting for someone familiar with the topic to write
something up or give at least provide some hints and pointers what to
write there.
The new document is dual-licensed under GPL-2.0+ or CC-BY-4.0. The
latter is way more liberal and makes it attractive to use this text as a
base when writing about this topic on websites or in books. This
hopefully increases the chances that such texts are accurate and stick
to official way of doing things.
[1] https://lkml.kernel.org/r/20201118172958.5b014a44@lwn.net
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e2db808f954744b79f10937a923d9c99bdca1fca.1607063223.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This cleans up a few titles with extra colons, and removes the
reference to kernel 2.2. The docs don't yet cover *all* of 5.10 or
5.11, but I think they're close enough. Most entries are documented,
and have been checked against current kernels.
Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20201208074922.30359-1-steve@sk2.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
We want the fixes in here, and this resolves a merge issue with
drivers/misc/habanalabs/common/memory.c.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix warnings from make htmlddocs:
Documentation/output/videodev2.h.rst:6: WARNING: undefined label: v4l2-meta-fmt-rk-isp1-params (if the link has no caption the label must precede a section header)
Documentation/output/videodev2.h.rst:6: WARNING: undefined label: v4l2-meta-fmt-rk-isp1-stat-3a (if the link has no caption the label must precede a section header)
Fixes: df22026aeb ("media: videodev2.h, v4l2-ioctl: add rkisp1 meta buffer format")
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Pull bootconfig fixes from Steven Rostedt:
"Have bootconfig size and checksum be little endian
In case the bootconfig is created on one kind of endian machine, and
then read on the other kind of endian kernel, the size and checksum
will be incorrect. Instead, have both the size and checksum always be
little endian and have the tool and the kernel convert it from little
endian to or from the host endian"
* tag 'trace-v5.10-rc6-bootconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
docs: bootconfig: Add the endianness of fields
tools/bootconfig: Store size and checksum in footer as le32
bootconfig: Load size and checksum in the footer as le32
Pull tracing fixes from Steven Rostedt:
- Use correct timestamp variable for ring buffer write stamp update
- Fix up before stamp and write stamp when crossing ring buffer sub
buffers
- Keep a zero delta in ring buffer in slow path if cmpxchg fails
- Fix trace_printk static buffer for archs that care
- Fix ftrace record accounting for ftrace ops with trampolines
- Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
- Remove WARN_ON in hwlat tracer that triggers on something that is OK
- Make "my_tramp" trampoline in ftrace direct sample code global
- Fixes in the bootconfig tool for better alignment management
* tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Always check to put back before stamp when crossing pages
ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
ftrace: Fix updating FTRACE_FL_TRAMP
tracing: Fix alignment of static buffer
tracing: Remove WARN_ON in start_thread()
samples/ftrace: Mark my_tramp[12]? global
ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
ring-buffer: Update write stamp with the correct ts
docs: bootconfig: Update file format on initrd image
tools/bootconfig: Align the bootconfig applied initrd image size to 4
tools/bootconfig: Fix to check the write failure correctly
tools/bootconfig: Fix errno reference after printf()
Pull powerpc fixes from Michael Ellerman:
"Fixes for CVE-2020-4788.
From Daniel's cover letter:
IBM Power9 processors can speculatively operate on data in the L1
cache before it has been completely validated, via a way-prediction
mechanism. It is not possible for an attacker to determine the
contents of impermissible memory using this method, since these
systems implement a combination of hardware and software security
measures to prevent scenarios where protected data could be leaked.
However these measures don't address the scenario where an attacker
induces the operating system to speculatively execute instructions
using data that the attacker controls. This can be used for example to
speculatively bypass "kernel user access prevention" techniques, as
discovered by Anthony Steinhauser of Google's Safeside Project. This
is not an attack by itself, but there is a possibility it could be
used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern.
This patch series flushes the L1 cache on kernel entry (patch 2) and
after the kernel performs any user accesses (patch 3). It also adds a
self-test and performs some related cleanups"
* tag 'powerpc-cve-2020-4788' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s: rename pnv|pseries_setup_rfi_flush to _setup_security_mitigations
selftests/powerpc: refactor entry and rfi_flush tests
selftests/powerpc: entry flush test
powerpc: Only include kup-radix.h for 64-bit Book3S
powerpc/64s: flush L1D after user accesses
powerpc/64s: flush L1D on kernel entry
selftests/powerpc: rfi_flush: disable entry flush if present
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.
This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
