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timerfd_settime

Implemented in Antinomie 0.7.0 · Syscall list

long timerfd_settime(int ufd, int flags, const struct __kernel_itimerspec *utmr, struct __kernel_itimerspec *otmr);
Number (x86-64) 286
ABI common
Kernel entry point sys_timerfd_settime

This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.

Arms or disarms a timerfd timer.

Name Type Meaning
ufd (arg0) int File descriptor to operate on.
flags (arg1) int Option flags that change the behavior of the call.
utmr (arg2) const struct __kernel_itimerspec * Pointer to a timerfd setting.
otmr (arg3) struct __kernel_itimerspec * Pointer to a buffer for the old timer value.

On success: 0.

In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.

Raw return Name Meaning
-9 EBADF A file descriptor is not valid for this operation.
-22 EINVAL An argument is invalid.

timerfd_settime(2) on man7.org

Coverage mark: Implemented. Every pointer argument has a capture rule in the pinned kernel patch and none of them records a “no decoder”, “address only” or “not observed” gap on any code path. Individual values can still be incomplete on a particular call; see the capture statuses.

Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).

Argument When How Recorded field key Condition
ufd (arg0) Entry raw scalar word args.0, args.ufd
flags (arg1) Entry raw scalar word; Syscall Trace also decodes it into flag names (timerfd_settime group), listing unknown bits separately args.1, args.flags
utmr (arg2) Entry the pointer itself, as a raw word args.2, args.raw[2]
↳ pointee Entry structure itimerspec (fixed size) arg2.data always
otmr (arg3) Entry the pointer itself, as a raw word args.3, args.raw[3]
↳ pointee Exit structure itimerspec (fixed size) arg3.data result is 0
  • Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
  • Argument words: args.ufd (arg0), args.flags (arg1), args.utmr (arg2), args.otmr (arg3); args.0 to args.5 by position.
  • Structure itimerspec behind utmr (arg2): args.utmr.<member> for it_interval.tv_nsec, it_interval.tv_sec, it_value.tv_nsec, it_value.tv_sec.
  • Structure itimerspec behind otmr (arg3): args.otmr.<member> for it_interval.tv_nsec, it_interval.tv_sec, it_value.tv_nsec, it_value.tv_sec.

See Syscall Trace filter for the full syntax.

For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.