svc · mach trap -18
_kernelrpc_mach_port_deallocate_trap
Trap-level entry point that backs mach_port_deallocate — drops one user reference on a send or send-once right.
Prototype
kern_return_t _kernelrpc_mach_port_deallocate_trap(/* 2 args */);Returns: kern_return_t
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-2050.18.24 | macOS 10.8 Mountain Lion | -18 |
| xnu-2422.115.4 | macOS 10.9 Mavericks | -18 |
| xnu-2782.40.9 | macOS 10.10 Yosemite | -18 |
| xnu-3247.1.106 | macOS 10.11 El Capitan | -18 |
| xnu-3789.1.32 | macOS 10.12 Sierra | -18 |
| xnu-4570.1.46 | macOS 10.13 High Sierra | -18 |
| xnu-4903.221.2 | macOS 10.14 Mojave | -18 |
| xnu-6153.11.26 | macOS 10.15 Catalina | -18 |
| xnu-7195.50.7.100.1 | macOS 11.0 Big Sur | -18 |
| xnu-8019.41.5 | macOS 12.0 Monterey | -18 |
| xnu-8792.41.9 | macOS 13.0 Ventura | -18 |
| xnu-10002.1.13 | macOS 14.0 Sonoma | -18 |
| xnu-11215.1.10 | macOS 15.0 Sequoia | -18 |
| xnu-11417.101.15 | macOS 15.4 Sequoia | -18 |
| xnu-12377.1.9 | macOS 26.0 Tahoe | -18 |
| xnu-10002.41.9 | — | -18 |
| xnu-10002.61.3 | — | -18 |
| xnu-10002.81.5 | — | -18 |
| xnu-10063.101.15 | — | -18 |
| xnu-10063.121.3 | — | -18 |
| xnu-10063.141.1 | — | -18 |
| xnu-11215.41.3 | — | -18 |
| xnu-11215.61.5 | — | -18 |
| xnu-11215.81.4 | — | -18 |
| xnu-11417.121.6 | — | -18 |
| xnu-11417.140.69 | — | -18 |
| xnu-12377.101.15 | — | -18 |
| xnu-12377.41.6 | — | -18 |
| xnu-12377.61.12 | — | -18 |
| xnu-12377.81.4 | — | -18 |
| xnu-2050.22.13 | — | -18 |
| xnu-2050.24.15 | — | -18 |
| xnu-2050.48.11 | — | -18 |
| xnu-2050.7.9 | — | -18 |
| xnu-2050.9.2 | — | -18 |
| xnu-2422.1.72 | — | -18 |
| xnu-2422.100.13 | — | -18 |
| xnu-2422.110.17 | — | -18 |
| xnu-2422.90.20 | — | -18 |
| xnu-2782.1.97 | — | -18 |
| xnu-2782.10.72 | — | -18 |
| xnu-2782.20.48 | — | -18 |
| xnu-2782.30.5 | — | -18 |
| xnu-3247.10.11 | — | -18 |
| xnu-3248.20.55 | — | -18 |
| xnu-3248.30.4 | — | -18 |
| xnu-3248.40.184 | — | -18 |
| xnu-3248.50.21 | — | -18 |
| xnu-3248.60.10 | — | -18 |
| xnu-3789.21.4 | — | -18 |
| xnu-3789.31.2 | — | -18 |
| xnu-3789.41.3 | — | -18 |
| xnu-3789.51.2 | — | -18 |
| xnu-3789.60.24 | — | -18 |
| xnu-3789.70.16 | — | -18 |
| xnu-4570.20.62 | — | -18 |
| xnu-4570.31.3 | — | -18 |
| xnu-4570.41.2 | — | -18 |
| xnu-4570.51.1 | — | -18 |
| xnu-4570.61.1 | — | -18 |
| xnu-4570.71.2 | — | -18 |
| xnu-4903.231.4 | — | -18 |
| xnu-4903.241.1 | — | -18 |
| xnu-4903.270.47 | — | -18 |
| xnu-6153.101.6 | — | -18 |
| xnu-6153.121.1 | — | -18 |
| xnu-6153.141.1 | — | -18 |
| xnu-6153.41.3 | — | -18 |
| xnu-6153.61.1 | — | -18 |
| xnu-6153.81.5 | — | -18 |
| xnu-7195.101.1 | — | -18 |
| xnu-7195.121.3 | — | -18 |
| xnu-7195.141.2 | — | -18 |
| xnu-7195.60.75 | — | -18 |
| xnu-7195.81.3 | — | -18 |
| xnu-8019.61.5 | — | -18 |
| xnu-8019.80.24 | — | -18 |
| xnu-8020.101.4 | — | -18 |
| xnu-8020.121.3 | — | -18 |
| xnu-8020.140.41 | — | -18 |
| xnu-8792.61.2 | — | -18 |
| xnu-8792.81.2 | — | -18 |
| xnu-8796.101.5 | — | -18 |
| xnu-8796.121.2 | — | -18 |
| xnu-8796.141.3 | — | -18 |
Notes
Deallocating a right decrements its userspace refcount; when the refcount hits zero the name is removed from the IPC space and, if the right was the last send right on the port, a no-senders notification fires for any subscriber. The trap is the workhorse of every libsyscall and MIG cleanup path — every successful mach_thread_self(), mach_msg receive with MOVE_SEND, and task_for_pid call pairs with a corresponding deallocate. Calling deallocate on a pinned port (mach_task_self, mach_thread_self on hardened-runtime processes) raises EXC_GUARD with kGUARD_EXC_MOD_REFS.
Detection
Not visible to Endpoint Security. DTrace observation point is mach_trap::_kernelrpc_mach_port_deallocate_trap:entry. Crashes from over-deallocating pinned ports show up as EXC_GUARD in ReportCrash with subtype kGUARD_EXC_MOD_REFS.