[Audit] round 9: generalize JIT-entry probe to PC-configurable cvar

Replace the round-7 hardcoded `current_guest_function_ == 0x824F7800`
gate with a runtime cvar `audit_jit_prolog_pc` (uint32, 0 = disabled).
The cvar names the guest entry PC at which the x64 emitter inserts a
CallNative to the prolog probe; the probe now dumps the active PC in
each log line so multiple instrumentation campaigns can share output.

Renames `audit_log_sub824F7800_args` (cvar) and `AuditLogSub824F7800Args`
(host function) — the round-7 sub_824F7800-specific cvar and function
are deleted, not left dormant. The `audit_handle_lifecycle` cvar and
its existing AUDIT-HLC probe sites in xboxkrnl_threading.cc /
kernel_state.cc are untouched.

Validated by audit-059 round 9: with `--audit_jit_prolog_pc=0x821B55D8`
the silph WorkerCtx-init chain entry fires 1× in canary at tid=6
lr=0x82172D8C (call site at sub_82172BA0+0x1E8 `bctrl`, the virtual
dispatch through vtable slot 6 that statically-blind xref-walkers
cannot enumerate).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/xenia/cpu/backend/x64/x64_emitter.cc

@@ -41,12 +41,13 @@
 
 DEFINE_bool(debugprint_trap_log, false,
             "Log debugprint traps to the active debugger", "CPU");
-DEFINE_bool(audit_log_sub824F7800_args, false,
+DEFINE_uint32(audit_jit_prolog_pc, 0,
-            "Emit one XELOGKERNEL line per JIT-compiled entry to guest function "
+              "Guest function entry PC at which to emit one XELOGKERNEL line "
-            "0x824F7800 (silph::WorkerCtx ctor's immediate caller; per audit-058 "
+              "per JIT-compiled entry. When non-zero, the x64 emitter inserts "
-            "fires exactly 1x after DiscImageDevice::ResolvePath). Dumps "
+              "a CallNative to AuditLogJitPrologArgs at the start of the JIT "
-            "r3..r10, LR, and 64 bytes at host(r3). Audit-059 round 7 probe — "
+              "body of the matching guest function. Dumps r3..r10, LR, and 64 "
-            "off by default.",
+              "bytes at host(r3). Zero (default) disables the probe. Audit-059 "
+              "round 7+ JIT-prolog probe — generic PC-configurable variant.",
               "Auditing");
 DEFINE_bool(ignore_undefined_externs, true,
             "Don't exit when an undefined extern is called.", "CPU");
@@ -277,14 +278,16 @@ bool X64Emitter::Emit(HIRBuilder* builder, EmitFunctionInfo& func_info) {
   count on no other code modifying it. mov(GetMembaseReg(),
       qword[GetContextReg() + offsetof(ppc::PPCContext, virtual_membase)]);
   */
-  // Audit-059 round 7: one-shot dump of r3..r10/LR at entry to sub_824F7800.
+  // Audit-059: PC-configurable JIT-prolog probe. Runtime-gated on the cvar
-  // Compile-time gated on guest function address; runtime gated on the cvar.
+  // audit_jit_prolog_pc (uint32; 0 disables). When non-zero and the current
+  // guest function's entry PC matches, emit a single CallNative to
+  // AuditLogJitPrologArgs that dumps r3..r10, LR, and 64 bytes at host(r3).
   // Emits *before* any body instruction runs, so r3..r10 / LR in PPCContext
   // still reflect the caller's args (no LOAD/STORE_CONTEXT has executed yet).
-  if (cvars::audit_log_sub824F7800_args &&
+  if (cvars::audit_jit_prolog_pc != 0u &&
-      current_guest_function_ == 0x824F7800u) {
+      current_guest_function_ == cvars::audit_jit_prolog_pc) {
-    extern uint64_t AuditLogSub824F7800Args(void* raw_context, uint64_t arg0);
+    extern uint64_t AuditLogJitPrologArgs(void* raw_context, uint64_t arg0);
-    CallNative(AuditLogSub824F7800Args, 0);
+    CallNative(AuditLogJitPrologArgs, 0);
   }
   // Body.
   auto block = builder->first_block();
@@ -454,12 +457,14 @@ uint64_t TrapDebugBreak(void* raw_context, uint64_t address) {
   return 0;
 }
 
-// Audit-059 round 7 probe: dump r3..r10, LR, and 64 bytes at host(r3) when
+// Audit-059 JIT-prolog probe: dump r3..r10, LR, and 64 bytes at host(r3)
-// the guest hits the JIT-compiled entry of sub_824F7800 (silph::WorkerCtx
+// when the guest hits the JIT-compiled entry of the function whose entry PC
-// ctor's immediate caller). Per audit-058 this fires exactly once after the
+// matches cvars::audit_jit_prolog_pc. Generic PC-configurable variant of the
-// DiscImageDevice::ResolvePath(\dat\movie) sequence on canary.
+// round-7 sub_824F7800 hook. The hook logs the current guest PC so multiple
-uint64_t AuditLogSub824F7800Args(void* raw_context, uint64_t /*unused*/) {
+// instrumentation campaigns can share log output.
+uint64_t AuditLogJitPrologArgs(void* raw_context, uint64_t /*unused*/) {
   auto* ctx = reinterpret_cast<ppc::PPCContext_s*>(raw_context);
+  uint32_t pc = static_cast<uint32_t>(cvars::audit_jit_prolog_pc);
   uint32_t r3 = static_cast<uint32_t>(ctx->r[3]);
   uint32_t r4 = static_cast<uint32_t>(ctx->r[4]);
   uint32_t r5 = static_cast<uint32_t>(ctx->r[5]);
@@ -473,9 +478,9 @@ uint64_t AuditLogSub824F7800Args(void* raw_context, uint64_t /*unused*/) {
   uint32_t tid = ctx->thread_state ? ctx->thread_state->thread_id() : 0u;
 
   XELOGKERNEL(
-      "AUDIT-HLC sub_824F7800 entry tid={:08X} r3={:08X} r4={:08X} r5={:08X} "
+      "AUDIT-HLC JitProlog pc={:08X} tid={:08X} r3={:08X} r4={:08X} r5={:08X} "
       "r6={:08X} r7={:08X} r8={:08X} r9={:08X} r10={:08X} lr={:08X}",
-      tid, r3, r4, r5, r6, r7, r8, r9, r10, lr);
+      pc, tid, r3, r4, r5, r6, r7, r8, r9, r10, lr);
 
   // Dump 64 bytes at host(r3) if r3 looks like a plausible guest VA.
   if (r3 >= 0x10000 && r3 < 0xE0000000) {
@@ -486,14 +491,17 @@ uint64_t AuditLogSub824F7800Args(void* raw_context, uint64_t /*unused*/) {
         uint32_t d1 = xe::load_and_swap<uint32_t>(host + off + 4);
         uint32_t d2 = xe::load_and_swap<uint32_t>(host + off + 8);
         uint32_t d3 = xe::load_and_swap<uint32_t>(host + off + 12);
-        XELOGKERNEL("AUDIT-HLC sub_824F7800 r3+{:02X}: {:08X} {:08X} {:08X} {:08X}",
+        XELOGKERNEL(
-                    off, d0, d1, d2, d3);
+            "AUDIT-HLC JitProlog pc={:08X} r3+{:02X}: {:08X} {:08X} {:08X} "
+            "{:08X}",
+            pc, off, d0, d1, d2, d3);
       }
     } else {
-      XELOGKERNEL("AUDIT-HLC sub_824F7800 r3 translate failed");
+      XELOGKERNEL("AUDIT-HLC JitProlog pc={:08X} r3 translate failed", pc);
     }
   } else {
-    XELOGKERNEL("AUDIT-HLC sub_824F7800 r3 out of VA range, skipping dump");
+    XELOGKERNEL("AUDIT-HLC JitProlog pc={:08X} r3 out of VA range, skipping dump",
+                pc);
   }
   return 0;
 }