This behaves like preadv2/pwritev2 with offset == -1, it'll use (and
update) the current file position. This obviously comes with the caveat
that if the application has multiple read/writes in flight, then the
end result will not be as expected. This is similar to threads sharing
a file descriptor and doing IO using the current file position.
Since this feature isn't easily detectable by doing a read or write,
add a feature flags, IORING_FEAT_RW_CUR_POS, to allow applications to
detect presence of this feature.
Reported-by: 李通洲 <carter.li@eoitek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For uses cases that don't already naturally have an iovec, it's easier
(or more convenient) to just use a buffer address + length. This is
particular true if the use case is from languages that want to create
a memory safe abstraction on top of io_uring, and where introducing
the need for the iovec may impose an ownership issue. For those cases,
they currently need an indirection buffer, which means allocating data
just for this purpose.
Add basic read/write that don't require the iovec.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring defaults to always doing inline submissions, if at all
possible. But for larger copies, even if the data is fully cached, that
can take a long time. Add an IOSQE_ASYNC flag that the application can
set on the SQE - if set, it'll ensure that we always go async for those
kinds of requests. Use the io-wq IO_WQ_WORK_CONCURRENT flag to ensure we
get the concurrency we desire for this case.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently fully quiesce the ring before an unregister or update of
the fixed fileset. This is very expensive, and we can be a bit smarter
about this.
Add a percpu refcount for the file tables as a whole. Grab a percpu ref
when we use a registered file, and put it on completion. This is cheap
to do. Upon removal of a file from a set, switch the ref count to atomic
mode. When we hit zero ref on the completion side, then we know we can
drop the previously registered files. When the old files have been
dropped, switch the ref back to percpu mode for normal operation.
Since there's a period between doing the update and the kernel being
done with it, add a IORING_OP_FILES_UPDATE opcode that can perform the
same action. The application knows the update has completed when it gets
the CQE for it. Between doing the update and receiving this completion,
the application must continue to use the unregistered fd if submitting
IO on this particular file.
This takes the runtime of test/file-register from liburing from 14s to
about 0.7s.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This works just like close(2), unsurprisingly. We remove the file
descriptor and post the completion inline, then offload the actual
(potential) last file put to async context.
Mark the async part of this work as uncancellable, as we really must
guarantee that the latter part of the close is run.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This works just like openat(2), except it can be performed async. For
the normal case of a non-blocking path lookup this will complete
inline. If we have to do IO to perform the open, it'll be done from
async context.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fds field of struct io_uring_files_update is problematic with regards
to compat user space, as pointer size is different in 32-bit, 32-on-64-bit,
and 64-bit user space. In order to avoid custom handling of compat in
the syscall implementation, make fds __u64 and use u64_to_user_ptr in
order to retrieve it. Also, align the field naturally and check that
no garbage is passed there.
Fixes: c3a31e6056 ("io_uring: add support for IORING_REGISTER_FILES_UPDATE")
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
cmdq:
- clean ups of unused code and debuggability
- add cmdq_instruction to make the function call interface more readable
- add functions for polling and providing info for the user of cmdq
scpsys:
- add bindings for MT6765
* tag 'v5.5-next-soc' of https://git.kernel.org/pub/scm/linux/kernel/git/matthias.bgg/linux:
dt-bindings: mediatek: add MT6765 power dt-bindings
soc: mediatek: cmdq: delete not used define
soc: mediatek: cmdq: add cmdq_dev_get_client_reg function
soc: mediatek: cmdq: add polling function
soc: mediatek: cmdq: define the instruction struct
soc: mediatek: cmdq: remove OR opertaion from err return
Link: https://lore.kernel.org/r/9b365e76-e346-f813-d750-d7cfd0d16e4e@gmail.com
Signed-off-by: Olof Johansson <olof@lixom.net>
Bitmaps are fairly popular for their space efficiency, but we don't have
generic iterators available. Make percpu's bitmap region iterators
available to everyone.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
ordered->start, ordered->len, and ordered->disk_len correspond to
fi->disk_bytenr, fi->num_bytes, and fi->disk_num_bytes, respectively.
It's confusing to translate between the two naming schemes. Since a
btrfs_ordered_extent is basically a pending btrfs_file_extent_item,
let's make the former use the naming from the latter.
Note that I didn't touch the names in tracepoints just in case there are
scripts depending on the current naming.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Monitoring tools that want to find out which resctrl control and monitor
groups a task belongs to must currently read the "tasks" file in every
group until they locate the process ID.
Add an additional file /proc/{pid}/cpu_resctrl_groups to provide this
information:
1) res:
mon:
resctrl is not available.
2) res:/
mon:
Task is part of the root resctrl control group, and it is not associated
to any monitor group.
3) res:/
mon:mon0
Task is part of the root resctrl control group and monitor group mon0.
4) res:group0
mon:
Task is part of resctrl control group group0, and it is not associated
to any monitor group.
5) res:group0
mon:mon1
Task is part of resctrl control group group0 and monitor group mon1.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jinshi Chen <jinshi.chen@intel.com>
Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com
It turned out that the recent simplification of HD-audio bus access
helpers caused a regression on the virtual HD-audio device on QEMU
with ARM platforms. The driver got a CORB/RIRB timeout and couldn't
probe any codecs.
The essential difference that caused a problem was the enforced
aligned MMIO accesses by simplification. Since snd-hda-tegra driver
is enabled on ARM, it enables CONFIG_SND_HDA_ALIGNED_MMIO, which makes
the all HD-audio drivers using the aligned MMIO accesses. While this
is mandatory for snd-hda-tegra, it seems that snd-hda-intel on ARM
gets broken by this access pattern.
For addressing the regression, this patch introduces a new flag,
aligned_mmio, to hdac_bus object, and applies the aligned MMIO only
when this flag is set. This change affects only platforms with
CONFIG_SND_HDA_ALIGNED_MMIO set, i.e. mostly only for ARM platforms.
Unfortunately the patch became a big bigger than it should be, just
because the former calls didn't take hdac_bus object in the argument,
hence we had to extend the call patterns.
Fixes: 19abfefd4c ("ALSA: hda: Direct MMIO accesses")
BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1161152
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200120104127.28985-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A number of network drivers has the same glue code to use phy_mii_ioctl
as ndo_do_ioctl handler. So let's add such a generic ndo_do_ioctl
handler to phylib.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is similar to what we have for omap5 except the gpu_cm address is
different, the mux clocks have one more source option, and there's no
divider clock.
Note that because of the current dts node name dependency for mapping to
clock domain, we must still use "gpu-clkctrl@" naming instead of generic
"clock@" naming for the node. And because of this, it's probably best to
apply the dts node addition together along with the other clock changes.
For accessing the GPU, we also need to configure the interconnect target
module for GPU similar to what we have for omap5, I'll send that change
separately.
Cc: Benoit Parrot <bparrot@ti.com>
Cc: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Robert Nelson <robertcnelson@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Most of the clock related dt-binding header files are located in
dt-bindings/clock folder. It would be good to keep all the similar
header files at a single location.
Suggested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Dave noticed that when specifying multiple efi_fake_mem= entries only
the last entry was successfully being reflected in the efi memory map.
This is due to the fact that the efi_memmap_insert() is being called
multiple times, but on successive invocations the insertion should be
applied to the last new memmap rather than the original map at
efi_fake_memmap() entry.
Rework efi_fake_memmap() to install the new memory map after each
efi_fake_mem= entry is parsed.
This also fixes an issue in efi_fake_memmap() that caused it to litter
emtpy entries into the end of the efi memory map. An empty entry causes
efi_memmap_insert() to attempt more memmap splits / copies than
efi_memmap_split_count() accounted for when sizing the new map. When
that happens efi_memmap_insert() may overrun its allocation, and if you
are lucky will spill over to an unmapped page leading to crash
signature like the following rather than silent corruption:
BUG: unable to handle page fault for address: ffffffffff281000
[..]
RIP: 0010:efi_memmap_insert+0x11d/0x191
[..]
Call Trace:
? bgrt_init+0xbe/0xbe
? efi_arch_mem_reserve+0x1cb/0x228
? acpi_parse_bgrt+0xa/0xd
? acpi_table_parse+0x86/0xb8
? acpi_boot_init+0x494/0x4e3
? acpi_parse_x2apic+0x87/0x87
? setup_acpi_sci+0xa2/0xa2
? setup_arch+0x8db/0x9e1
? start_kernel+0x6a/0x547
? secondary_startup_64+0xb6/0xc0
Commit af16489848 "x86/efi: Update e820 with reserved EFI boot
services data to fix kexec breakage" introduced more occurrences where
efi_memmap_insert() is invoked after an efi_fake_mem= configuration has
been parsed. Previously the side effects of vestigial empty entries were
benign, but with commit af16489848 that follow-on efi_memmap_insert()
invocation triggers efi_memmap_insert() overruns.
Reported-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20191231014630.GA24942@dhcp-128-65.nay.redhat.com
Link: https://lore.kernel.org/r/20200113172245.27925-14-ardb@kernel.org
In preparation for fixing efi_memmap_alloc() leaks, add support for
recording whether the memmap was dynamically allocated from slab,
memblock, or is the original physical memmap provided by the platform.
Given this tracking is established in efi_memmap_alloc() and needs to be
carried to efi_memmap_install(), use 'struct efi_memory_map_data' to
convey the flags.
Some small cleanups result from this reorganization, specifically the
removal of local variables for 'phys' and 'size' that are already
tracked in @data.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-12-ardb@kernel.org
In preparation for garbage collecting dynamically allocated EFI memory
maps, where the allocation method of memblock vs slab needs to be
recalled, convert the existing 'late' flag into a 'flags' bitmask.
Arrange for the flag to be passed via 'struct efi_memory_map_data'. This
structure grows additional flags in follow-on changes.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-11-ardb@kernel.org
Pull networking fixes from David Miller:
1) Fix non-blocking connect() in x25, from Martin Schiller.
2) Fix spurious decryption errors in kTLS, from Jakub Kicinski.
3) Netfilter use-after-free in mtype_destroy(), from Cong Wang.
4) Limit size of TSO packets properly in lan78xx driver, from Eric
Dumazet.
5) r8152 probe needs an endpoint sanity check, from Johan Hovold.
6) Prevent looping in tcp_bpf_unhash() during sockmap/tls free, from
John Fastabend.
7) hns3 needs short frames padded on transmit, from Yunsheng Lin.
8) Fix netfilter ICMP header corruption, from Eyal Birger.
9) Fix soft lockup when low on memory in hns3, from Yonglong Liu.
10) Fix NTUPLE firmware command failures in bnxt_en, from Michael Chan.
11) Fix memory leak in act_ctinfo, from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
cxgb4: reject overlapped queues in TC-MQPRIO offload
cxgb4: fix Tx multi channel port rate limit
net: sched: act_ctinfo: fix memory leak
bnxt_en: Do not treat DSN (Digital Serial Number) read failure as fatal.
bnxt_en: Fix ipv6 RFS filter matching logic.
bnxt_en: Fix NTUPLE firmware command failures.
net: systemport: Fixed queue mapping in internal ring map
net: dsa: bcm_sf2: Configure IMP port for 2Gb/sec
net: dsa: sja1105: Don't error out on disabled ports with no phy-mode
net: phy: dp83867: Set FORCE_LINK_GOOD to default after reset
net: hns: fix soft lockup when there is not enough memory
net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()
net/sched: act_ife: initalize ife->metalist earlier
netfilter: nat: fix ICMP header corruption on ICMP errors
net: wan: lapbether.c: Use built-in RCU list checking
netfilter: nf_tables: fix flowtable list del corruption
netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()
netfilter: nf_tables: remove WARN and add NLA_STRING upper limits
netfilter: nft_tunnel: ERSPAN_VERSION must not be null
netfilter: nft_tunnel: fix null-attribute check
...
Add packet trap that can report NVE packets that the device decided to
drop because their overlay source MAC is multicast.
Signed-off-by: Amit Cohen <amitc@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add packet trap that can report packets that reached the router, but are
non-routable. For example, IGMP queries can be flooded by the device in
layer 2 and reach the router. Such packets should not be routed and
instead dropped.
Signed-off-by: Amit Cohen <amitc@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Saeed Mahameed says:
====================
Mellanox, mlx5 E-Switch chains and prios
This series has two parts,
1) A merge commit with mlx5-next branch that include updates for mlx5
HW layouts needed for this and upcoming submissions.
2) From Paul, Increase the number of chains and prios
Currently the Mellanox driver supports offloading tc rules that
are defined on the first 4 chains and the first 16 priorities.
The restriction stems from the firmware flow level enforcement
requiring a flow table of a certain level to point to a flow
table of a higher level. This limitation may be ignored by setting
the ignore_flow_level bit when creating flow table entries.
Use unmanaged tables and ignore flow level to create more tables than
declared by fs_core steering. Manually manage the connections between the
tables themselves.
HW table is instantiated for every tc <chain,prio> tuple. The miss rule
of every table either jumps to the next <chain,prio> table, or continues
to slow_fdb. This logic is realized by following this sequence:
1. Create an auto-grouped flow table for the specified priority with
reserved entries
Reserved entries are allocated at the end of the flow table.
Flow groups are evaluated in sequence and therefore it is guaranteed
that the flow group defined on the last FTEs will be the last to evaluate.
Define a "match all" flow group on the reserved entries, providing
the platform to add table miss actions.
2. Set the miss rule action to jump to the next <chain,prio> table
or the slow_fdb.
3. Link the previous priority table to point to the new table by
updating its miss rule.
Please pull and let me know if there's any problem.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Jonathan writes:
Second set of new device support, features and minor fixes for IIO in the 5.6 cycle
Just a small set this time.
As we are very near the merge window, I've rolled a few fixes in here
rather than adding noise just before release. A short delay here will
do little harm.
New device support
* adis16480
- Add support for adis16490. After earlier rework this is simple ID plus
chip info.
Features
* kxcjk1013
- mount matrix support.
* lsm_6dsx
- mount matrix support.
Cleanups / minor or late breaking fixes
* ad7124
- add support to ad-sigma-delta and use it in this driver to allow
the the interrupt type to be IRQF_TRIGGER_LOW unlike most other devices
using this framework.
* adis
- use delay structure now available in SPI to handle transfer delays
- introduce a timeouts structure to allow support of new devices
* ak8975
- drop platform data support. No one is using it and it adds complexity.
- use device_get_match_data rather than open coding much the same thing.
* dht11
- drop meaningless todo
* at91-samad2_adc
- switch to dma_request_chan
* altas-sensor
- add a helper function to compute number of channels. Needed for new device
support that is under review.
* bma400
- add a lower bound check on scale.
* inv_mpu6050
- add support for temperature data in the fifos for all chips.
- support an odd situation where a board supports only interrupt triggering
on both edges.
* st_lsm6dsx
- check and handle potential error return.
* st_sensors
- fix some values for the LSM9DS0 which is ever so slightly different from
other devices using the same whoami value.
- switch over to generic functions from dt ones, avoiding need for separate
ACPI support.
* stm32-adc
- switch to dma_request_chan
- suppress an error print in deferred probe case.
* stm32-dac
- drop private data structure element for reset controller as only used in
probe.
- reflect more cleanly that the reset controller is optional whilst ensuring
that if is specified any errors are caught.
* stm32-dfsdm
- switch to dma_request_chan
- fix missing application of formatting to single conversions.
- ensure the sampling rate is updated when the oversampling ratio is changed.
* tag 'iio-for-5.6b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (29 commits)
iio: dac: stm32-dac: better handle reset controller failures
iio: dac: stm32-dac: use reset controller only at probe time
dt-bindings: iio: accel: kxcjk1013: Document mount-matrix property
iio: accel: kxcjk1013: Support orientation matrix
iio: imu: st_lsm6dsx: add mount matrix support
iio: adc: stm32-adc: don't print an error on probe deferral
dt-bindings: iio: adis16480: add compatible entry for ADIS16490
iio: imu: adis16480: Add support for ADIS16490
iio: accel: bma400: prevent setting accel scale too low
iio: imu/mpu6050: support dual-edge IRQ
iio: imu: inv_mpu6050: add fifo temperature data support
iio: magnetometer: ak8975: Convert to use device_get_match_data()
iio: magnetometer: ak8975: Get rid of platform data
iio: adc: ad7124: Set IRQ type to falling
iio: adc: ad-sigma-delta: Allow custom IRQ flags
iio: imu: adis: use new `delay` structure for SPI transfer delays
iio: adc: stm32-dfsdm: adapt sampling rate to oversampling ratio
iio: adc: stm32-dfsdm: fix single conversion
iio: st_sensors: Make use of device properties
iio: st_sensors: Drop redundant parameter from st_sensors_of_name_probe()
...
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next, they are:
1) Incorrect uapi header comment in bitwise, from Jeremy Sowden.
2) Fetch flow statistics if flow is still active.
3) Restrict flow matching on hardware based on input device.
4) Add nf_flow_offload_work_alloc() helper function.
5) Remove the last client of the FLOW_OFFLOAD_DYING flag, use teardown
instead.
6) Use atomic bitwise operation to operate with flow flags.
7) Add nf_flowtable_hw_offload() helper function to check for the
NF_FLOWTABLE_HW_OFFLOAD flag.
8) Add NF_FLOW_HW_REFRESH to retry hardware offload from the flowtable
software datapath.
9) Remove indirect calls in xt_hashlimit, from Florian Westphal.
10) Add nf_flow_offload_tuple() helper to consolidate code.
11) Add nf_flow_table_offload_cmd() helper function.
12) A few whitespace cleanups in nf_tables in bitwise and the bitmap/hash
set types, from Jeremy Sowden.
13) Cleanup netlink attribute checks in bitwise, from Jeremy Sowden.
14) Replace goto by return in error path of nft_bitwise_dump(), from
Jeremy Sowden.
15) Add bitwise operation netlink attribute, also from Jeremy.
16) Add nft_bitwise_init_bool(), from Jeremy Sowden.
17) Add nft_bitwise_eval_bool(), also from Jeremy.
18) Add nft_bitwise_dump_bool(), from Jeremy Sowden.
19) Disallow hardware offload for other that NFT_BITWISE_BOOL,
from Jeremy Sowden.
20) Add NFTA_BITWISE_DATA netlink attribute, again from Jeremy.
21) Add support for bitwise shift operation, from Jeremy Sowden.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull drm fixes from Dave Airlie:
"Back from LCA2020, fixes wasn't too busy last week, seems to have
quieten down appropriately, some amdgpu, i915, then a core mst fix and
one fix for virtio-gpu and one for rockchip:
core mst:
- serialize down messages and clear timeslots are on unplug
amdgpu:
- Update golden settings for renoir
- eDP fix
i915:
- uAPI fix: Remove dash and colon from PMU names to comply with
tools/perf
- Fix for include file that was indirectly included
- Two fixes to make sure VMA are marked active for error capture
virtio:
- maintain obj reservation lock when submitting cmds
rockchip:
- increase link rate var size to accommodate rates"
* tag 'drm-fixes-2020-01-19' of git://anongit.freedesktop.org/drm/drm:
drm/amd/display: Reorder detect_edp_sink_caps before link settings read.
drm/amdgpu: update goldensetting for renoir
drm/dp_mst: Have DP_Tx send one msg at a time
drm/dp_mst: clear time slots for ports invalid
drm/i915/pmu: Do not use colons or dashes in PMU names
drm/rockchip: fix integer type used for storing dp data rate
drm/i915/gt: Mark ring->vma as active while pinned
drm/i915/gt: Mark context->state vma as active while pinned
drm/i915/gt: Skip trying to unbind in restore_ggtt_mappings
drm/i915: Add missing include file <linux/math64.h>
drm/virtio: add missing virtio_gpu_array_lock_resv call
Pull rseq fixes from Ingo Molnar:
"Two rseq bugfixes:
- CLONE_VM !CLONE_THREAD didn't work properly, the kernel would end
up corrupting the TLS of the parent. Technically a change in the
ABI but the previous behavior couldn't resonably have been relied
on by applications so this looks like a valid exception to the ABI
rule.
- Make the RSEQ_FLAG_UNREGISTER ABI behavior consistent with the
handling of other flags. This is not thought to impact any
applications either"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Unregister rseq for clone CLONE_VM
rseq: Reject unknown flags on rseq unregister
Hardware could be physically mounted in any possible direction and
userpspace needs to be aware of the mounting orientation in order to
process sensor's data correctly. In particular this helps iio-sensor-proxy
to report display's orientation properly on a phone/tablet devices.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
/* Background. */
For a very long time, extending openat(2) with new features has been
incredibly frustrating. This stems from the fact that openat(2) is
possibly the most famous counter-example to the mantra "don't silently
accept garbage from userspace" -- it doesn't check whether unknown flags
are present[1].
This means that (generally) the addition of new flags to openat(2) has
been fraught with backwards-compatibility issues (O_TMPFILE has to be
defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old
kernels gave errors, since it's insecure to silently ignore the
flag[2]). All new security-related flags therefore have a tough road to
being added to openat(2).
Userspace also has a hard time figuring out whether a particular flag is
supported on a particular kernel. While it is now possible with
contemporary kernels (thanks to [3]), older kernels will expose unknown
flag bits through fcntl(F_GETFL). Giving a clear -EINVAL during
openat(2) time matches modern syscall designs and is far more
fool-proof.
In addition, the newly-added path resolution restriction LOOKUP flags
(which we would like to expose to user-space) don't feel related to the
pre-existing O_* flag set -- they affect all components of path lookup.
We'd therefore like to add a new flag argument.
Adding a new syscall allows us to finally fix the flag-ignoring problem,
and we can make it extensible enough so that we will hopefully never
need an openat3(2).
/* Syscall Prototype. */
/*
* open_how is an extensible structure (similar in interface to
* clone3(2) or sched_setattr(2)). The size parameter must be set to
* sizeof(struct open_how), to allow for future extensions. All future
* extensions will be appended to open_how, with their zero value
* acting as a no-op default.
*/
struct open_how { /* ... */ };
int openat2(int dfd, const char *pathname,
struct open_how *how, size_t size);
/* Description. */
The initial version of 'struct open_how' contains the following fields:
flags
Used to specify openat(2)-style flags. However, any unknown flag
bits or otherwise incorrect flag combinations (like O_PATH|O_RDWR)
will result in -EINVAL. In addition, this field is 64-bits wide to
allow for more O_ flags than currently permitted with openat(2).
mode
The file mode for O_CREAT or O_TMPFILE.
Must be set to zero if flags does not contain O_CREAT or O_TMPFILE.
resolve
Restrict path resolution (in contrast to O_* flags they affect all
path components). The current set of flags are as follows (at the
moment, all of the RESOLVE_ flags are implemented as just passing
the corresponding LOOKUP_ flag).
RESOLVE_NO_XDEV => LOOKUP_NO_XDEV
RESOLVE_NO_SYMLINKS => LOOKUP_NO_SYMLINKS
RESOLVE_NO_MAGICLINKS => LOOKUP_NO_MAGICLINKS
RESOLVE_BENEATH => LOOKUP_BENEATH
RESOLVE_IN_ROOT => LOOKUP_IN_ROOT
open_how does not contain an embedded size field, because it is of
little benefit (userspace can figure out the kernel open_how size at
runtime fairly easily without it). It also only contains u64s (even
though ->mode arguably should be a u16) to avoid having padding fields
which are never used in the future.
Note that as a result of the new how->flags handling, O_PATH|O_TMPFILE
is no longer permitted for openat(2). As far as I can tell, this has
always been a bug and appears to not be used by userspace (and I've not
seen any problems on my machines by disallowing it). If it turns out
this breaks something, we can special-case it and only permit it for
openat(2) but not openat2(2).
After input from Florian Weimer, the new open_how and flag definitions
are inside a separate header from uapi/linux/fcntl.h, to avoid problems
that glibc has with importing that header.
/* Testing. */
In a follow-up patch there are over 200 selftests which ensure that this
syscall has the correct semantics and will correctly handle several
attack scenarios.
In addition, I've written a userspace library[4] which provides
convenient wrappers around openat2(RESOLVE_IN_ROOT) (this is necessary
because no other syscalls support RESOLVE_IN_ROOT, and thus lots of care
must be taken when using RESOLVE_IN_ROOT'd file descriptors with other
syscalls). During the development of this patch, I've run numerous
verification tests using libpathrs (showing that the API is reasonably
usable by userspace).
/* Future Work. */
Additional RESOLVE_ flags have been suggested during the review period.
These can be easily implemented separately (such as blocking auto-mount
during resolution).
Furthermore, there are some other proposed changes to the openat(2)
interface (the most obvious example is magic-link hardening[5]) which
would be a good opportunity to add a way for userspace to restrict how
O_PATH file descriptors can be re-opened.
Another possible avenue of future work would be some kind of
CHECK_FIELDS[6] flag which causes the kernel to indicate to userspace
which openat2(2) flags and fields are supported by the current kernel
(to avoid userspace having to go through several guesses to figure it
out).
[1]: https://lwn.net/Articles/588444/
[2]: https://lore.kernel.org/lkml/CA+55aFyyxJL1LyXZeBsf2ypriraj5ut1XkNDsunRBqgVjZU_6Q@mail.gmail.com
[3]: commit 629e014bb8 ("fs: completely ignore unknown open flags")
[4]: https://sourceware.org/bugzilla/show_bug.cgi?id=17523
[5]: https://lore.kernel.org/lkml/20190930183316.10190-2-cyphar@cyphar.com/
[6]: https://youtu.be/ggD-eb3yPVs
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Vinod writes:
soundwire updates for v5.6-rc1
This round we have bunch of updates to interfaces for ASoC (audio)
subsystem by Intel and a new Qualcomm controller driver
Details
- Updates for sdw_slave interfaces for ASoC
- Updates to cadence library and intel driver
- New Soundwire controller for Qualcomm masters
- Rework of device number assignment
* tag 'soundwire-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire: (27 commits)
dt-bindings: soundwire: fix example
soundwire: cadence: fix kernel-doc parameter descriptions
soundwire: intel: report slave_ids for each link to SOF driver
soundwire: intel: fix factor of two in MCLK handling
soundwire: bus: fix device number leak on errors
soundwire: cadence: remove useless variable incrementation
soundwire: cadence: update kernel-doc parameter descriptions
soundwire: qcom: add support for SoundWire controller
dt-bindings: soundwire: add bindings for Qcom controller
soundwire: bus: check first if Slaves become UNATTACHED
soundwire: cadence_master: handle multiple status reports per Slave
soundwire: cadence_master: remove config update for interrupt setting
soundwire: cadence_master: log more useful information during timeouts
soundwire: cadence_master: clear interrupt status before enabling interrupt
soundwire: cadence_master: filter out bad interrupts
soundwire: stream: remove redundant pr_err traces
soundwire: intel: add clock stop quirks
soundwire: intel: add mutex for shared SHIM register access
soundwire: intel: add prototype for WAKEEN interrupt processing
soundwire: intel: add link_list to handle interrupts with a single thread
...
Since IIO framework supports device property API and driver has been moved
already to the use of GPIO descriptors the logical continuation is to
get rid of platform data completely. We are on the safe side here since
there are no users of it in the kernel.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Before this patch the ad_sigma_delta implementation hardcoded
the irq trigger type to low, assuming that all Sigma-Delta ADCs
have the same interrupt-type.
This patch allows all drivers using the ad_sigma_delta layer to set the
irq trigger type to the one specified in the datasheet.
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
