Mach messages: task_access

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osfmk/mach/task_access.defs. Service/callback interface outside the ordinary kernel kobject table. Follow local sender/receiver evidence; external service bodies are not supplied by the declaration. Registration evidence: mig_e.

Reading these entries

IDs are computed from the explicit preprocessing profiles in the catalog guide, counting both routines and skip slots. They are not discovered from a running kernel. Each entry retains all observed names/declaration locations; the displayed fields come from the first non-skipped profile. Alternative declarations can have different fields. simpleroutine is one-way at the MIG interface level.

An interface contract block quotes the adjacent local .defs comment with whitespace normalized. Mechanism paragraphs explain selected implementation decisions. Local body links and call names identify implementation evidence; syntactic call lists are reading aids, not a proof that every listed call executes on every path. Short complete implementation bodies are included where especially useful.

Complete routine and reserved-slot catalog

27000: check_task_access

Interface contract:

Verify task_for_pid access for the given pid Access granted by return value (success/failure)

Mechanism: This older declaration omits the explicit requested flavor. Current visible task-port acquisition uses check_task_access_with_flavor; no same-symbol local receiver was resolved. Policy and authentication must be supplied by the external task-access service, not inferred from the argument list.

Declarations: check_task_access (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine check_task_access(
  task_access_port : mach_port_t;
  calling_pid : int32_t;
  calling_gid : uint32_t;
  target_pid : int32_t;
  ServerAuditToken caller_cred : audit_token_t);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files.

27001: find_code_signature

Interface contract:

Search for a code signature for unsigned executables

Mechanism: Exec can ask the task-access service to locate/attach signing information for the new PID through a synchronous wrapper. The source contains this call boundary and subsequent exec signing policy, not the daemon's signature search/database. See executable signature policy. Local path.

Declarations: find_code_signature (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine find_code_signature(
  task_access_port : mach_port_t;
  new_pid : int32_t);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/kern/kern_exec.c:8480. These may be senders, wrappers or declarations; they do not establish a local receiver.

27002: check_task_access_with_flavor

Ask the external task-access policy service whether a caller may obtain the requested task-port flavor.

Mechanism: The task-port acquisition path invokes the taskgated upcall with calling PID/GID, target PID and requested task-port flavor. The source shows the privileged access decision boundary; the external daemon implements its policy. Local process/credential checks and subsequent task-right conversion still surround that request. Local path.

Declarations: check_task_access_with_flavor (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine check_task_access_with_flavor(
  task_access_port : mach_port_t;
  calling_pid : int32_t;
  calling_gid : uint32_t;
  target_pid : int32_t;
  flavor : mach_task_flavor_t;
  ServerAuditToken caller_cred : audit_token_t);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/kern/kern_proc.c:5848. These may be senders, wrappers or declarations; they do not establish a local receiver.