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open_tree

Implemented in Antinomie 0.7.0 · Syscall list

long open_tree(int dfd, const char *path, unsigned int flags);
Number (x86-64) 428
ABI common
Kernel entry point sys_open_tree

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

Gets a descriptor for a mount tree, optionally cloned, to use with move_mount.

Name Type Meaning
dfd (arg0) int Directory file descriptor that a relative path is resolved against, or AT_FDCWD (-100) for the current directory.
path (arg1) const char * Path, as a NUL-terminated string in user memory.
flags (arg2) unsigned int Option flags that change the behavior of the call.

On success: A new file descriptor (a non-negative number).

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
-2 ENOENT A path component or the named object does not exist.
-1 EPERM The operation is not permitted for this process.

open_tree(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
dfd (arg0) Entry raw scalar word args.0, args.dfd
path (arg1) Entry the pointer itself, as a raw word args.1, args.raw[1]
↳ pointee Entry NUL-terminated string, up to 4,096 bytes (PATH_MAX) arg1.path always
flags (arg2) Entry raw scalar word; Syscall Trace also decodes it into flag names (open_tree group), listing unknown bits separately args.2, args.flags
  • Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
  • Argument words: args.dfd (arg0), args.path (arg1), args.flags (arg2); args.0 to args.5 by position.
  • Captured strings: the args.<name> field of a path argument, and args.path, give the captured text instead of the pointer.

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.