BSD syscall#391
svc · unix #391
__mac_get_lcid
Retrieves the MAC label for a login context identifier.
Prototype
int __mac_get_lcid(pid_t lcid, struct mac *mac_p);Returns: int
Arguments
| Name | Type | Dir | Description |
|---|---|---|---|
| lcid | pid_t | - | |
| mac_p | struct mac | - |
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-1456.1.26 | macOS 10.6 Snow Leopard | 391 |
| xnu-1699.24.8 | macOS 10.7 Lion | 391 |
| xnu-2050.18.24 | macOS 10.8 Mountain Lion | 391 |
| xnu-2422.115.4 | macOS 10.9 Mavericks | 391 |
| xnu-2782.40.9 | macOS 10.10 Yosemite | 391 |
| xnu-1486.2.11 | — | 391 |
| xnu-1504.15.3 | — | 391 |
| xnu-1504.3.12 | — | 391 |
| xnu-1504.7.4 | — | 391 |
| xnu-1504.9.17 | — | 391 |
| xnu-1504.9.26 | — | 391 |
| xnu-1504.9.37 | — | 391 |
| xnu-1699.22.73 | — | 391 |
| xnu-1699.22.81 | — | 391 |
| xnu-1699.24.23 | — | 391 |
| xnu-1699.26.8 | — | 391 |
| xnu-1699.32.7 | — | 391 |
| xnu-2050.22.13 | — | 391 |
| xnu-2050.24.15 | — | 391 |
| xnu-2050.48.11 | — | 391 |
| xnu-2050.7.9 | — | 391 |
| xnu-2050.9.2 | — | 391 |
| xnu-2422.1.72 | — | 391 |
| xnu-2422.100.13 | — | 391 |
| xnu-2422.110.17 | — | 391 |
| xnu-2422.90.20 | — | 391 |
| xnu-2782.1.97 | — | 391 |
| xnu-2782.10.72 | — | 391 |
| xnu-2782.20.48 | — | 391 |
| xnu-2782.30.5 | — | 391 |
Notes
Login contexts (lctx) were an early macOS abstraction grouping all processes belonging to a single login. __mac_get_lcid lets a privileged caller pull the MAC label for that group. The lctx machinery was largely deprecated when audit sessions took over the session-tracking role, so the syscall is effectively dormant on modern macOS.
Detection
Essentially never called; treat any invocation as anomalous and capture the calling image via DTrace.
Related APIs
__mac_get_lctx__mac_set_lctxaudit_session_self