linux: remove locks around callout_drain in timerfd_close()

The lock around callout_drain() is unnecessary and may cause
deadlock when one closes a timer descriptor during timer execution.

Reviewed

linux: remove locks around callout_drain in timerfd_close()

The lock around callout_drain() is unnecessary and may cause
deadlock when one closes a timer descriptor during timer execution.

Reviewed By: delphij
Submitted By: ankohuu_outlook.com (Shunchao Hu)
Differential Revision: https://reviews.freebsd.org/D28148

(cherry picked from commit 14c40d2c292deff44be5591add7fdad5f9b371aa)

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epoll: Store epoll_event udata member in ext member of kevent.

Current epoll implementation stores udata fields of epoll_event
structure in special dynamically-sized table rather than in udata field

epoll: Store epoll_event udata member in ext member of kevent.

Current epoll implementation stores udata fields of epoll_event
structure in special dynamically-sized table rather than in udata field
of backing kevent structure because of 2 reasons:
1. Kevent's udata size is smaller than epoll's on 32-bit archs.
2. Kevent's udata can be clobbered on execution EPOLL_CTL_ADD as kqueue
modifies existing event while epoll returns error in this case.

After r320043 has introduced four new 64bit user data members (ext[]),
we can store epoll udata in one of them and drop aforementioned table.
According to kqueue_register() source code ext members are not updated
when existing kevent is modified that fixes p.2.

As a side effect the patch fixes PR/252582.

Reviewed by: trasz
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D28169

(cherry picked from commit b3c6fe663bb90240f8bda6b5ba9c6a761f09f078)

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linux: make timerfd_settime(2) set expirations count to zero

On Linux, read(2) from a timerfd file descriptor returns an unsigned
8-byte integer (uint64_t) containing the number of expirations
that

linux: make timerfd_settime(2) set expirations count to zero

On Linux, read(2) from a timerfd file descriptor returns an unsigned
8-byte integer (uint64_t) containing the number of expirations
that have occurred, if the timer has already expired one or more
times since its settings were last modified using timerfd_settime(),
or since the last successful read(2). That's to say, once we do
a read or call timerfd_settime(), timer fd's expiration count should
be zero. Some Linux applications create timerfd and add it to epoll
with LT mode, when event comes, they do timerfd_settime instead
of read to stop event source from trigger. On FreeBSD,
timerfd_settime(2) didn't set the count to zero, which caused high
CPU utilization.

Submitted by: ankohuu_outlook.com (Shunchao Hu)
Differential Revision: https://reviews.freebsd.org/D28231

(cherry picked from commit ae71b794cbed19e5e25effc3438720ad452ab87c)

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Convert remaining cap_rights_init users to cap_rights_init_one

semantic patch:

@@

expression rights, r;

@@

- cap_rights_init(&rights, r)
+ cap_rights_init_one(&rights, r)

Expose eventfd in the native API/ABI using a new __specialfd syscall

eventfd is a Linux system call that produces special file descriptors
for event notification. When porting Linux software, it is

Expose eventfd in the native API/ABI using a new __specialfd syscall

eventfd is a Linux system call that produces special file descriptors
for event notification. When porting Linux software, it is currently
usually emulated by epoll-shim on top of kqueues. Unfortunately, kqueues
are not passable between processes. And, as noted by the author of
epoll-shim, even if they were, the library state would also have to be
passed somehow. This came up when debugging strange HW video decode
failures in Firefox. A native implementation would avoid these problems
and help with porting Linux software.

Since we now already have an eventfd implementation in the kernel (for
the Linuxulator), it's pretty easy to expose it natively, which is what
this patch does.

Submitted by: [email protected]
Reviewed by: markj (previous version)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26668

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Remove useless ARGUSED annotations.

Submitted by: [email protected]

Add SPDX tag.

Submitted by: [email protected]

compat: clean up empty lines in .c and .h files

Don't use newlines with linux_msg(). No functional changes.

MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Linux epoll: Allow passing of any negative timeout value to epoll_wait

Linux epoll allow passing of any negative timeout value to epoll_wait()
to cause unbound blocking

Reviewed by: emaste
MFC afte

Linux epoll: Allow passing of any negative timeout value to epoll_wait

Linux epoll allow passing of any negative timeout value to epoll_wait()
to cause unbound blocking

Reviewed by: emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22517

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Linux epoll: Register events with zero event mask

Such an events are legal and should be interpreted as EPOLLERR | EPOLLHUP.
Register a disabled kqueue event in that case as we do not support EPOLLH

Linux epoll: Register events with zero event mask

Such an events are legal and should be interpreted as EPOLLERR | EPOLLHUP.
Register a disabled kqueue event in that case as we do not support EPOLLHUP yet.

Required by Linux Steam client.

PR: 240590
Reported by: Alex S <[email protected]>
Reviewed by: emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22516

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Linux epoll: Check both read and write kqueue events existence in EPOLL_CTL_ADD

Linux epoll EPOLL_CTL_ADD op handler should always check registration
of both EVFILT_READ and EVFILT_WRITE kevents to

Linux epoll: Check both read and write kqueue events existence in EPOLL_CTL_ADD

Linux epoll EPOLL_CTL_ADD op handler should always check registration
of both EVFILT_READ and EVFILT_WRITE kevents to deceide if supplied
file descriptor fd is already registered with epoll instance.

Reviewed by: emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22515

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Linux epoll: Don't deregister file descriptor after EPOLLONESHOT is fired

Linux epoll does not remove descriptor after one-shot event has been triggered.
Set EV_DISPATCH kqueue flag rather then EV_O

Linux epoll: Don't deregister file descriptor after EPOLLONESHOT is fired

Linux epoll does not remove descriptor after one-shot event has been triggered.
Set EV_DISPATCH kqueue flag rather then EV_ONESHOT to get the same behavior.

Required by Linux Steam client.

PR: 240590
Reported by: Alex S <[email protected]>
Reviewed by: emaste, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22513

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Pass malloc flags directly through kevent(2) subroutines.

Some kevent functions have a boolean "waitok" parameter for use when
calling malloc(9). Replace them with the corresponding malloc() flags:

Pass malloc flags directly through kevent(2) subroutines.

Some kevent functions have a boolean "waitok" parameter for use when
calling malloc(9). Replace them with the corresponding malloc() flags:
the desired behaviour is known at compile-time, so this eliminates a
couple of conditional branches, and makes the code easier to read.

No functional change intended.

Reviewed by: kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18318

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Make timespecadd(3) and friends public

The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have

Make timespecadd(3) and friends public

The timespecadd(3) family of macros were imported from NetBSD back in
r35029. However, they were initially guarded by #ifdef _KERNEL. In the
meantime, we have grown at least 28 syscalls that use timespecs in some
way, leading many programs both inside and outside of the base system to
redefine those macros. It's better just to make the definitions public.

Our kernel currently defines two-argument versions of timespecadd and
timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define
three-argument versions. Solaris also defines a three-argument version, but
only in its kernel. This revision changes our definition to match the
common three-argument version.

Bump _FreeBSD_version due to the breaking KPI change.

Discussed with: cem, jilles, ian, bde
Differential Revision: https://reviews.freebsd.org/D14725

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linuxulator: do not include legacy syscalls on arm64

Existing linuxulator platforms (i386, amd64) support legacy syscalls,
such as non-*at ones like open, but arm64 and other new platforms do
not.

linuxulator: do not include legacy syscalls on arm64

Existing linuxulator platforms (i386, amd64) support legacy syscalls,
such as non-*at ones like open, but arm64 and other new platforms do
not.

Wrap these in #ifdef LINUX_LEGACY_SYSCALLS, #defined in the MD linux.h
files. We may need finer grained control in the future but this is
sufficient for now.

Reviewed by: andrew
Sponsored by: Turing Robotic Industries
Differential Revision: https://reviews.freebsd.org/D15237

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Eliminate the overhead of gratuitous repeated reinitialization of cap_rights

- Add macros to allow preinitialization of cap_rights_t.

- Convert most commonly used code paths to use preinitialized c

Eliminate the overhead of gratuitous repeated reinitialization of cap_rights

- Add macros to allow preinitialization of cap_rights_t.

- Convert most commonly used code paths to use preinitialized cap_rights_t.
A 3.6% speedup in fstat was measured with this change.

Reported by: mjg
Reviewed by: oshogbo
Approved by: sbruno
MFC after: 1 month

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Linuxolator whitespace cleanup

A version of each of the MD files by necessity exists for each CPU
architecture supported by the Linuxolator. Clean these up so that new
architectures do not inherit

Linuxolator whitespace cleanup

A version of each of the MD files by necessity exists for each CPU
architecture supported by the Linuxolator. Clean these up so that new
architectures do not inherit whitespace issues.

Clean up shared Linuxolator files while here.

Sponsored by: Turing Robotic Industries Inc.

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Linux epoll return EEXIST on case when op is EPOLL_CTL_ADD, and the supplied
file descriptor fd is already registered with this epoll instance.

MFC after: 1 month

Linux epoll return ENOENT error in case when op is EPOLL_CTL_MOD or
EPOLL_CTL_DEL, and fd is not registered with this epoll instance.

MFC after: 1 month

FreeBSD does not have analgue for epill EPOLLPRI event type.
So, do not set EPOLLPRI event acidently.
Also, do not set EPOLLWRNORM and EPOLLRDNORM events as epoll
do not set this events.

MFC after:

FreeBSD does not have analgue for epill EPOLLPRI event type.
So, do not set EPOLLPRI event acidently.
Also, do not set EPOLLWRNORM and EPOLLRDNORM events as epoll
do not set this events.

MFC after: 1 month

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Return EINVAL when an invalid file descriptor specified.

MFC after: 1 month

Unify eventfd ioctl method and use it for other similar interfaces.

MFC after: 1 month

Return EINVAL in case when an invalid size of signal mask specified.

MFC after: 1 month

Restore signal mask in epoll_pwait.

MFC after: 1 month