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semget

Implemented in Antinomie 0.7.0 · Syscall list

long semget(key_t key, int nsems, int semflg);
Number (x86-64) 64
ABI common
Kernel entry point sys_semget

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

Creates or looks up a System V semaphore set.

Name Type Meaning
key (arg0) key_t Key, either a numeric key or a pointer to a key description.
nsems (arg1) int Number of semaphores.
semflg (arg2) int Semaphore flags.

On success: a semaphore set id.

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
-17 EEXIST The object already exists.
-22 EINVAL An argument is invalid.
-2 ENOENT A path component or the named object does not exist.

semget(2) on man7.org

Coverage mark: Implemented. All arguments are plain values, recorded as the raw argument words at entry. There is no pointee to copy and no known gap.

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
key (arg0) Entry raw scalar word args.0, args.key
nsems (arg1) Entry raw scalar word args.1, args.nsems
semflg (arg2) Entry raw scalar word; Syscall Trace also decodes it into flag names (ipc_create group), listing unknown bits separately args.2, args.semflg
  • Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
  • Argument words: args.key (arg0), args.nsems (arg1), args.semflg (arg2); args.0 to args.5 by position.

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.