Pull io_uring fixes from Jens Axboe:
"Quieter week this time, which was both expected and desired. About
half of the below is fixes for this release, the other half are just
fixes in general. In detail:
- Fix the freezing of IO threads, by making the freezer not send them
fake signals. Make them freezable by default.
- Like we did for personalities, move the buffer IDR to xarray. Kills
some code and avoids a use-after-free on teardown.
- SQPOLL cleanups and fixes (Pavel)
- Fix linked timeout race (Pavel)
- Fix potential completion post use-after-free (Pavel)
- Cleanup and move internal structures outside of general kernel view
(Stefan)
- Use MSG_SIGNAL for send/recv from io_uring (Stefan)"
* tag 'io_uring-5.12-2021-03-19' of git://git.kernel.dk/linux-block:
io_uring: don't leak creds on SQO attach error
io_uring: use typesafe pointers in io_uring_task
io_uring: remove structures from include/linux/io_uring.h
io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() calls
io_uring: fix sqpoll cancellation via task_work
io_uring: add generic callback_head helpers
io_uring: fix concurrent parking
io_uring: halt SQO submission on ctx exit
io_uring: replace sqd rw_semaphore with mutex
io_uring: fix complete_post use ctx after free
io_uring: fix ->flags races by linked timeouts
io_uring: convert io_buffer_idr to XArray
io_uring: allow IO worker threads to be frozen
kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing
When irq_matrix_free() is called for an unallocated vector the
managed_allocated and total_allocated counters get out of sync with the
real state of the matrix. Later, when the last interrupt is freed, these
counters will underflow resulting in UINTMAX because the counters are
unsigned.
While this is certainly a problem of the calling code, this can be catched
in the allocator by checking the allocation bit for the to be freed vector
which simplifies debugging.
An example of the problem described above:
https://lore.kernel.org/lkml/20210318192819.636943062@linutronix.de/
Add the missing sanity check and emit a warning when it triggers.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210319111823.1105248-1-vkuznets@redhat.com
Sites that match init_section_contains() get marked as INIT. For
built-in code init_sections contains both __init and __exit text. OTOH
kernel_text_address() only explicitly includes __init text (and there
are no __exit text markers).
Match what jump_label already does and ignore the warning for INIT
sites. Also see the excellent changelog for commit: 8f35eaa5f2
("jump_label: Don't warn on __exit jump entries")
Fixes: 9183c3f9ed ("static_call: Add inline static call infrastructure")
Reported-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lkml.kernel.org/r/20210318113610.739542434@infradead.org
The intent is to avoid writing init code after init (because the text
might have been freed). The code is needlessly different between
jump_label and static_call and not obviously correct.
The existing code relies on the fact that the module loader clears the
init layout, such that within_module_init() always fails, while
jump_label relies on the module state which is more obvious and
matches the kernel logic.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lkml.kernel.org/r/20210318113610.636651340@infradead.org
The ww_acquire_ctx structure for ww_mutex needs to persist for a complete
lock/unlock cycle. In the ww_mutex test in locktorture, however, both
ww_acquire_init() and ww_acquire_fini() are called within the lock
function only. This causes a lockdep splat of "WARNING: Nested lock
was not taken" when lockdep is enabled in the kernel.
To fix this problem, we need to move the ww_acquire_fini() after
the ww_mutex_unlock() in torture_ww_mutex_unlock(). This is done by
allocating a global array of ww_acquire_ctx structures. Each locking
thread is associated with its own ww_acquire_ctx via the unique thread
id it has so that both the lock and unlock functions can access the
same ww_acquire_ctx structure.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210318172814.4400-6-longman@redhat.com
To allow the lock and unlock functions in locktorture to access
per-thread information, we need to pass some hint on how to locate
those information. One way to do this is to pass in a unique thread
id which can then be used to access a global array for thread specific
information.
Change the lock and unlock method to add a thread id parameter which
can be determined by the offset of the lwsp/lrsp pointer from the global
lwsa/lrsa array.
There is no other functional change in this patch.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210318172814.4400-5-longman@redhat.com
In order to avoid false positive circular locking lockdep splat
when runnng the ww_mutex torture test, we need to make sure that
the ww_mutexes have the same lock class as the acquire_ctx. This
means the ww_mutexes must have the same lockdep key as the
acquire_ctx. Unfortunately the current DEFINE_WW_MUTEX() macro fails
to do that. As a result, we add an init method for the ww_mutex test
to do explicit ww_mutex_init()'s of the ww_mutexes to avoid the false
positive warning.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210318172814.4400-3-longman@redhat.com
Note that sugov_update_next_freq() may return false, that means the
caller sugov_fast_switch() will do nothing except fast switch check.
Similarly, sugov_deferred_update() also has unnecessary operations
of raw_spin_{lock,unlock} in sugov_update_single_freq() for that case.
So, let's call sugov_update_next_freq() before the fast switch check
to avoid unnecessary behaviors above. Accordingly, update interface
definition to sugov_deferred_update() and remove sugov_fast_switch()
since we will call cpufreq_driver_fast_switch() directly instead.
Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This reverts commit d60cd06331.
This patch causes a panic when rebooting my Dell Poweredge r440. I do
not have the full panic log as it's lost at that stage of the reboot and
I do not have a serial console. Reverting this patch makes my system
able to reboot again.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is working
towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error
path handling from each XDP ethernet driver to devmap code. According to
the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx
loop whenever the hw reports a tx error and it will just return to devmap
caller the number of successfully transmitted frames. It will be devmap
responsibility to free dropped frames.
Move each XDP ndo_xdp_xmit capable driver to the new APIs:
- veth
- virtio-net
- mvneta
- mvpp2
- socionext
- amazon ena
- bnxt
- freescale (dpaa2, dpaa)
- xen-frontend
- qede
- ice
- igb
- ixgbe
- i40e
- mlx5
- ti (cpsw, cpsw-new)
- tun
- sfc
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org
The fexit/fmod_ret programs can be attached to kernel functions that can sleep.
The synchronize_rcu_tasks() will not wait for such tasks to complete.
In such case the trampoline image will be freed and when the task
wakes up the return IP will point to freed memory causing the crash.
Solve this by adding percpu_ref_get/put for the duration of trampoline
and separate trampoline vs its image life times.
The "half page" optimization has to be removed, since
first_half->second_half->first_half transition cannot be guaranteed to
complete in deterministic time. Every trampoline update becomes a new image.
The image with fmod_ret or fexit progs will be freed via percpu_ref_kill and
call_rcu_tasks. Together they will wait for the original function and
trampoline asm to complete. The trampoline is patched from nop to jmp to skip
fexit progs. They are freed independently from the trampoline. The image with
fentry progs only will be freed via call_rcu_tasks_trace+call_rcu_tasks which
will wait for both sleepable and non-sleepable progs to complete.
Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU
Link: https://lore.kernel.org/bpf/20210316210007.38949-1-alexei.starovoitov@gmail.com
Given we know the max possible value of ptr_limit at the time of retrieving
the latter, add basic assertions, so that the verifier can bail out if
anything looks odd and reject the program. Nothing triggered this so far,
but it also does not hurt to have these.
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Instead of having the mov32 with aux->alu_limit - 1 immediate, move this
operation to retrieve_ptr_limit() instead to simplify the logic and to
allow for subsequent sanity boundary checks inside retrieve_ptr_limit().
This avoids in future that at the time of the verifier masking rewrite
we'd run into an underflow which would not sign extend due to the nature
of mov32 instruction.
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
retrieve_ptr_limit() computes the ptr_limit for registers with stack and
map_value type. ptr_limit is the size of the memory area that is still
valid / in-bounds from the point of the current position and direction
of the operation (add / sub). This size will later be used for masking
the operation such that attempting out-of-bounds access in the speculative
domain is redirected to remain within the bounds of the current map value.
When masking to the right the size is correct, however, when masking to
the left, the size is off-by-one which would lead to an incorrect mask
and thus incorrect arithmetic operation in the non-speculative domain.
Piotr found that if the resulting alu_limit value is zero, then the
BPF_MOV32_IMM() from the fixup_bpf_calls() rewrite will end up loading
0xffffffff into AX instead of sign-extending to the full 64 bit range,
and as a result, this allows abuse for executing speculatively out-of-
bounds loads against 4GB window of address space and thus extracting the
contents of kernel memory via side-channel.
Fixes: 979d63d50c ("bpf: prevent out of bounds speculation on pointer arithmetic")
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
The purpose of this patch is to streamline error propagation and in particular
to propagate retrieve_ptr_limit() errors for pointer types that are not defining
a ptr_limit such that register-based alu ops against these types can be rejected.
The main rationale is that a gap has been identified by Piotr in the existing
protection against speculatively out-of-bounds loads, for example, in case of
ctx pointers, unprivileged programs can still perform pointer arithmetic. This
can be abused to execute speculatively out-of-bounds loads without restrictions
and thus extract contents of kernel memory.
Fix this by rejecting unprivileged programs that attempt any pointer arithmetic
on unprotected pointer types. The two affected ones are pointer to ctx as well
as pointer to map. Field access to a modified ctx' pointer is rejected at a
later point in time in the verifier, and 7c69673262 ("bpf: Permit map_ptr
arithmetic with opcode add and offset 0") only relevant for root-only use cases.
Risk of unprivileged program breakage is considered very low.
Fixes: 7c69673262 ("bpf: Permit map_ptr arithmetic with opcode add and offset 0")
Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
On RT a task which has soft interrupts disabled can block on a lock and
schedule out to idle while soft interrupts are pending. This triggers the
warning in the NOHZ idle code which complains about going idle with pending
soft interrupts. But as the task is blocked soft interrupt processing is
temporarily blocked as well which means that such a warning is a false
positive.
To prevent that check the per CPU state which indicates that a scheduled
out task has soft interrupts disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.527563866@linutronix.de
vtime_account_irq and irqtime_account_irq() base checks on preempt_count()
which fails on RT because preempt_count() does not contain the softirq
accounting which is seperate on RT.
These checks do not need the full preempt count as they only operate on the
hard and softirq sections.
Use irq_count() instead which provides the correct value on both RT and non
RT kernels. The compiler is clever enough to fold the masking for !RT:
99b: 65 8b 05 00 00 00 00 mov %gs:0x0(%rip),%eax
- 9a2: 25 ff ff ff 7f and $0x7fffffff,%eax
+ 9a2: 25 00 ff ff 00 and $0xffff00,%eax
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.153926793@linutronix.de
tasklet_unlock_spin_wait() spin waits for the TASKLET_STATE_SCHED bit in
the tasklet state to be cleared. This works on !RT nicely because the
corresponding execution can only happen on a different CPU.
On RT softirq processing is preemptible, therefore a task preempting the
softirq processing thread can spin forever.
Prevent this by invoking local_bh_disable()/enable() inside the loop. In
case that the softirq processing thread was preempted by the current task,
current will block on the local lock which yields the CPU to the preempted
softirq processing thread. If the tasklet is processed on a different CPU
then the local_bh_disable()/enable() pair is just a waste of processor
cycles.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.988908275@linutronix.de
tasklet_kill() spin waits for TASKLET_STATE_SCHED to be cleared invoking
yield() from inside the loop. yield() is an ill defined mechanism and the
result might still be wasting CPU cycles in a tight loop which is
especially painful in a guest when the CPU running the tasklet is scheduled
out.
tasklet_kill() is used in teardown paths and not performance critical at
all. Replace the spin wait with wait_var_event().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.890532921@linutronix.de
tasklet_unlock_wait() spin waits for TASKLET_STATE_RUN to be cleared. This
is wasting CPU cycles in a tight loop which is especially painful in a
guest when the CPU running the tasklet is scheduled out.
tasklet_unlock_wait() is invoked from tasklet_kill() which is used in
teardown paths and not performance critical at all. Replace the spin wait
with wait_var_event().
There are no users of tasklet_unlock_wait() which are invoked from atomic
contexts. The usage in tasklet_disable() has been replaced temporarily with
the spin waiting variant until the atomic users are fixed up and will be
converted to the sleep wait variant later.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.783936921@linutronix.de
For userspace checkpoint and restore (C/R) a way of getting process state
containing RSEQ configuration is needed.
There are two ways this information is going to be used:
- to re-enable RSEQ for threads which had it enabled before C/R
- to detect if a thread was in a critical section during C/R
Since C/R preserves TLS memory and addresses RSEQ ABI will be restored
using the address registered before C/R.
Detection whether the thread is in a critical section during C/R is needed
to enforce behavior of RSEQ abort during C/R. Attaching with ptrace()
before registers are dumped itself doesn't cause RSEQ abort.
Restoring the instruction pointer within the critical section is
problematic because rseq_cs may get cleared before the control is passed
to the migrated application code leading to RSEQ invariants not being
preserved. C/R code will use RSEQ ABI address to find the abort handler
to which the instruction pointer needs to be set.
To achieve above goals expose the RSEQ ABI address and the signature value
with the new ptrace request PTRACE_GET_RSEQ_CONFIGURATION.
This new ptrace request can also be used by debuggers so they are aware
of stops within restartable sequences in progress.
Signed-off-by: Piotr Figiel <figiel@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michal Miroslaw <emmir@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20210226135156.1081606-1-figiel@google.com
The use_ww_ctx flag is passed to mutex_optimistic_spin(), but the
function doesn't use it. The frequent use of the (use_ww_ctx && ww_ctx)
combination is repetitive.
In fact, ww_ctx should not be used at all if !use_ww_ctx. Simplify
ww_mutex code by dropping use_ww_ctx from mutex_optimistic_spin() an
clear ww_ctx if !use_ww_ctx. In this way, we can replace (use_ww_ctx &&
ww_ctx) by just (ww_ctx).
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210316153119.13802-2-longman@redhat.com
The following sequence of commands:
register_ftrace_direct(ip, addr1);
modify_ftrace_direct(ip, addr1, addr2);
unregister_ftrace_direct(ip, addr2);
will cause the kernel to warn:
[ 30.179191] WARNING: CPU: 2 PID: 1961 at kernel/trace/ftrace.c:5223 unregister_ftrace_direct+0x130/0x150
[ 30.180556] CPU: 2 PID: 1961 Comm: test_progs W O 5.12.0-rc2-00378-g86bc10a0a711-dirty #3246
[ 30.182453] RIP: 0010:unregister_ftrace_direct+0x130/0x150
When modify_ftrace_direct() changes the addr from old to new it should update
the addr stored in ftrace_direct_funcs. Otherwise the final
unregister_ftrace_direct() won't find the address and will cause the splat.
Fixes: 0567d68091 ("ftrace: Add modify_ftrace_direct()")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20210316195815.34714-1-alexei.starovoitov@gmail.com
Currently, the lockdown state is queried unconditionally, even though
its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in
attr.sample_type. While that doesn't matter in case of the Lockdown LSM,
it causes trouble with the SELinux's lockdown hook implementation.
SELinux implements the locked_down hook with a check whether the current
task's type has the corresponding "lockdown" class permission
("integrity" or "confidentiality") allowed in the policy. This means
that calling the hook when the access control decision would be ignored
generates a bogus permission check and audit record.
Fix this by checking sample_type first and only calling the hook when
its result would be honored.
Fixes: b0c8fdc7fd ("lockdown: Lock down perf when in confidentiality mode")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Link: https://lkml.kernel.org/r/20210224215628.192519-1-omosnace@redhat.com
For cpu events, it'd better allocating them in the corresponding node
memory as they would be mostly accessed by the target cpu. Although
perf tools sets the cpu affinity before calling perf_event_open, there
are places it doesn't (notably perf record) and we should consider
other external users too.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311115413.444407-2-namhyung@kernel.org
The kernel can allocate a lot of struct perf_event when profiling. For
example, 256 cpu x 8 events x 20 cgroups = 40K instances of the struct
would be allocated on a large system.
The size of struct perf_event in my setup is 1152 byte. As it's
allocated by kmalloc, the actual allocation size would be rounded up
to 2K.
Then there's 896 byte (~43%) of waste per instance resulting in total
~35MB with 40K instances. We can create a dedicated kmem_cache to
avoid such a big unnecessary memory consumption.
With this change, I can see below (note this machine has 112 cpus).
# grep perf_event /proc/slabinfo
perf_event 224 784 1152 7 2 : tunables 24 12 8 : slabdata 112 112 0
The sixth column is pages-per-slab which is 2, and the fifth column is
obj-per-slab which is 7. Thus actually it can use 1152 x 7 = 8064
byte in the 8K, and wasted memory is (8192 - 8064) / 7 = ~18 byte per
instance.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311115413.444407-1-namhyung@kernel.org
fanotify has some hardcoded limits. The only APIs to escape those limits
are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS.
Allow finer grained tuning of the system limits via sysfs tunables under
/proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify,
with some minor differences.
- max_queued_events - global system tunable for group queue size limit.
Like the inotify tunable with the same name, it defaults to 16384 and
applies on initialization of a new group.
- max_user_marks - user ns tunable for marks limit per user.
Like the inotify tunable named max_user_watches, on a machine with
sufficient RAM and it defaults to 1048576 in init userns and can be
further limited per containing user ns.
- max_user_groups - user ns tunable for number of groups per user.
Like the inotify tunable named max_user_instances, it defaults to 128
in init userns and can be further limited per containing user ns.
The slightly different tunable names used for fanotify are derived from
the "group" and "mark" terminology used in the fanotify man pages and
throughout the code.
Considering the fact that the default value for max_user_instances was
increased in kernel v5.10 from 8192 to 1048576, leaving the legacy
fanotify limit of 8192 marks per group in addition to the max_user_marks
limit makes little sense, so the per group marks limit has been removed.
Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own
marks are not accounted in the per user marks account, so in effect the
limit of max_user_marks is only for the collection of groups that are
not initialized with FAN_UNLIMITED_MARKS.
Link: https://lore.kernel.org/r/20210304112921.3996419-2-amir73il@gmail.com
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Fix typos in kernel doc, otherwise validation script complains:
.../irq_sim.c:170: warning: Function parameter or member 'fwnode' not described in 'irq_domain_create_sim'
.../irq_sim.c:170: warning: Excess function parameter 'fnode' description in 'irq_domain_create_sim'
.../irq_sim.c:240: warning: Function parameter or member 'fwnode' not described in 'devm_irq_domain_create_sim'
.../irq_sim.c:240: warning: Excess function parameter 'fnode' description in 'devm_irq_domain_create_sim'
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210302161453.28540-1-andriy.shevchenko@linux.intel.com
Linus Torvalds