The needdofsync global variable was initialized as true, when it should be false. Fix this.

Fix formatting issue in license text

Move SIG_FOREACH() into an #ifdef _KERNEL.

Fix formatting in HISTORY section thanks to @gbe.

I would like to get this patch committed before the 14.0 freeze in August. I am personally in favor of making these syscalls, but I'd like some notice if we're not going this route.

Add brief comments explaining each of the tfd_jumped macros.

Use cap_svflags instead of cap_flags when determining kernel ABI with syscallabi().

Change NI_LCF_STRICTRELATIVE to NI_LCF_STRICTREL where applicable.

• tfd_jumped must be set to TFD_CANCELED, not TFD_JUMPED, for timerfd_settime to return ECANCELED.
• style(9) line-break fixes courtesy of @mckusick.

Er? Can you explain? What is confusing for ioctl, and what is intuitive for the syscall interface?

Why? I do not like it very much. It is not as if all (or most) other individual kernel ops where performed by dedicated syscall entries, so I do not see a good reason to do it there. Ioctl perfectly fits the intent of providing file-specific requests.

• Support TFD_TIMER_CANCEL_ON_SET settime flag using timerfd_jumped().
• Convert ioctl() interface to native syscalls.

In D40177#914781, @imp wrote:

There's a general preference to include sys/_types.h instead of sys/types.h

This differential is superseded by this review:
https://reviews.freebsd.org/D40177
which covers some more include self-containment issues in aarch64.

In D38459#903657, @val_packett.cool wrote:

Hey, couple random notes:

• re: "Developers that wish to support FreeBSD should avoid using timerfd" in the quarterly… :/
  • file descriptor handle based APIs are actually kinda better because composability / fd-passing / capability mode friendliness
    • FreeBSD invented procdesc(4) soo it's strange that we're not yet striving to turn everything into a file descriptor and Linux has us beat on this…
  • also there's no explicit clock selection in EVFILT_TIMER so when we finally add a suspend-aware monotonic clock it would only be possible to explicitly choose suspend-awareness-or-not with timerfd :)

Quick update: I'm nearly finished with my school work for the year, so I've had more time to work on this. I've nearly re-engineered the entire patch and I'm passing ~95% of the epoll-shim timerfd testing suite. I should have a new patch out in the next week (hopefully).

In D38459#896885, @kib wrote:

What is the destiny of these patches? Why did you not committed them still?

Use AT_STDIN instead of STDIN_FILENO to force read from stdin in readpassphraseat().

• cdfd is no longer a global variable. Instead, it is passed locally per function call.
• Open _PATH_TTY, limit its rights, and use readpassphraseat() instead of readpassphrase().
• Limit stdio instead of just stdin.

In D39009#888934, @markj wrote:

This looks good! Three comments:

• I don't like that cdfd is a global variable. I'd rather see it plumbed everywhere that we pass a path, even though that's kind of onerous.

In D38459#881824, @brooks wrote:

BTW, something that will need testing is to verify that the timerfd_gettime and timerfd_settime pseudo syscalls work in capability mode.

Open current directory, enter capability mode, then use *at() syscalls to extract archive files.

Alter function names and comments for clarity

• Remove __FBSDID tag
• Move SYSINIT to avoid forward declaring timerfd_init()
• Correctly check for read blocking in FIONREADioctl case

Fix minor logic error in FIONREAD ioctl case

• Use SYSINIT() to initialize timerfd ino unit number
• Use atomic bitwise operations for file flags in FIONBIO ioctl
• Return 0 when FNONBLOCK is not set in FIONREAD ioctl

• Add generic ioctl() support for FIONBIO and FIONREAD

• M_TIMERFD malloc type is now static
• style(9) fixes
• TFD_GETTIME32 will only be defined on amd64 machines

In D38420#881831, @bz wrote:

EAFNOTSUP; sorry, I'll try to give it a try within 48 hours. @jfree can you do drm testing?

• Use SV_CURPROC_FLAG() to determine if TFD_GETTIME32 compatibility instructions should be executed.

• Use _IOC_NEWTYPE() for COMPAT32 ioctls().

• Correct COMPAT32 pointer mistakes in struct timerfd_settime_args32
• tfdino_unr is now global static for unique ino generation

• struct itimerspec32 is now uint32_t in timerfd_settime_args32
• memset() itimerspec32s with zeros to avoid data leakage
• Remove DTYPE_TIMERFD checks for tfd fops.
• Various style(9) fixes

• Add tfd_ino field to struct timerfd for inode identification.

Pass timerfd_settime_args into TFD_SETTIME ioctl() to minimize kernel entries.

Use timerfd_settime_user() to copyin timerfd_settime_args members.

The TFD_SETTIME ioctl() now returns old_time in an effort to avoid race conditions between threads using the same timerfd fd. This reduces the number of kernel traps from 3 to 2 in timerfd_settime().

Sorry, a cut-and-paste error made that make no sense. My initial worry was about TFD_GETTIME and TFD_SETTIME, but actually it's both. Consider the following scenario:

thread0       thread1
TFD_GETTIME
TFD_SETFLAGS
              TFD_GETTIME
              TFD_SETFLAGS
              TFD_SETTIME
TFD_SETTIME

I'm not sure how important it is to prevent this problem in practice, but multiple system calls seem to make problems more likely.

Change file license from BSD-2-Clause-FreeBSD to BSD-2-Clause

• Add fo_stat implementation for timerfd
• ifdef _kernel TFD compat32 ioctl() macros

In D38460#879425, @brooks wrote:

Is the race between TFD_GETTIME and TFD_SETTIME in timerfd_settime acceptable? I wonder if TFD_SETFLAGS should be _IOWR and always return the previous value.

• Remove unnecessary headers
• Fix style(9) formatting