fork

Implemented in Antinomie 0.7.0 · Syscall list

Synopsis

long fork(void);

Number (x86-64)	57
ABI	common
Kernel entry point	sys_fork

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

Description

Creates a child process that is a copy of the caller.

Arguments

The call takes no arguments.

Return value

On success: the child’s pid in the parent, 0 in the child.

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.

Common errors

Raw return	Name	Meaning
-11	EAGAIN	The call would block, or a resource is temporarily unavailable.
-12	ENOMEM	The kernel is out of memory.

Man page

fork(2) on man7.org

Captured by Antinomie

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).

Derived and lifecycle records

• A lifecycle.child_cookie, lifecycle.child_pid, lifecycle.child_tgid and lifecycle.child_start_boot_ns record is emitted for the new task when the kernel creates it (this is how Antinomie builds the process tree).

Filter fields

• Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
• Argument words: none; 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.