[MIPS] Implementation of sel_ldr for MIPS architecture.

src/trusted/service_runtime/arch/mips/nacl_tls.c

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "native_client/src/include/nacl_platform.h"
 #include "native_client/src/include/nacl_macros.h"
 #include "native_client/src/include/portability.h"
 #include "native_client/src/shared/platform/nacl_check.h"
 #include "native_client/src/shared/platform/nacl_sync_checked.h"
-#include "native_client/src/trusted/service_runtime/arch/arm/sel_ldr_arm.h"
+#include "native_client/src/trusted/service_runtime/arch/mips/sel_ldr_mips.h"
 #include "native_client/src/trusted/service_runtime/nacl_app_thread.h"
 #include "native_client/src/trusted/service_runtime/nacl_globals.h"
 #include "native_client/src/trusted/service_runtime/nacl_tls.h"
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
 #include "native_client/src/trusted/service_runtime/sel_memory.h"
 
 static struct NaClMutex gNaClTlsMu;
 static int gNaClThreadIdxInUse[NACL_THREAD_MAX];  /* bool */
-static size_t const kNumThreads = NACL_ARRAY_SIZE_UNSAFE(gNaClThreadIdxInUse);
 
 /*
  * This holds the index of the current thread.
  * This is also used directly in nacl_syscall.S (NaClSyscallSeg).
  */
 __thread uint32_t gNaClThreadIdx = NACL_TLS_INDEX_INVALID;
 
 uint32_t NaClTlsGetIdx(void) {
   return gNaClThreadIdx;
 }
 
 void NaClTlsSetIdx(uint32_t tls_idx) {
   gNaClThreadIdx = tls_idx;
 }
 
 uint32_t NaClGetThreadIdx(struct NaClAppThread *natp) {
   return natp->user.tls_idx;
 }
 
 
 int NaClTlsInit() {
   size_t i;
 
   NaClLog(2, "NaClTlsInit\n");
 
-  for (i = 0; i < kNumThreads; i++) {
+  for (i = 0; i < NACL_ARRAY_SIZE(gNaClThreadIdxInUse); i++) {
     gNaClThreadIdxInUse[i] = 0;
   }
   if (!NaClMutexCtor(&gNaClTlsMu)) {
     NaClLog(LOG_WARNING,
             "NaClTlsInit: gNaClTlsMu initialization failed\n");
     return 0;
   }
 
   return 1;
 }
 
 
 void NaClTlsFini() {
   NaClLog(2, "NaClTlsFini\n");
   NaClMutexDtor(&gNaClTlsMu);
 }
 
+
 static int NaClThreadIdxAllocate() {
-  size_t i;
+  int i;
 
   NaClXMutexLock(&gNaClTlsMu);
-  for (i = 1; i < kNumThreads; i++) {
+  for (i = 0; i < NACL_THREAD_MAX; i++) {
     if (!gNaClThreadIdxInUse[i]) {
       gNaClThreadIdxInUse[i] = 1;
       break;
     }
   }
   NaClXMutexUnlock(&gNaClTlsMu);
 
-  if (kNumThreads != i) {
+  if (NACL_THREAD_MAX != i) {
     return i;
   }
 
   NaClLog(LOG_ERROR, "NaClThreadIdxAllocate: no more slots for a thread\n");
-  return NACL_TLS_INDEX_INVALID;
+  return -1;
 }
 
 
 /*
  * Allocation does not mean we can set gNaClThreadIdx, since we are not
  * that thread.  Setting it must wait until the thread actually launches.
  */
 uint32_t NaClTlsAllocate(struct NaClAppThread *natp) {
   int idx = NaClThreadIdxAllocate();
 
   NaClLog(2, "NaClTlsAllocate: $tp %x idx %d\n", natp->tls_values.tls1, idx);
-  if (NACL_TLS_INDEX_INVALID != idx) {
-    natp->user.r9 = natp->tls_values.tls1;
+  if (-1 == idx) {
+    NaClLog(LOG_FATAL,
+            "NaClTlsAllocate: thread limit reached\n");
+    return NACL_TLS_INDEX_INVALID;
   }
 
-  return idx;
+  natp->user.t8 = natp->tls_values.tls1;
+
+  /*
+   * Bias by 1: successful return value is never 0.
+   */
+  return idx + 1;
 }
 
 
 void NaClTlsFree(struct NaClAppThread *natp) {
   uint32_t idx = NaClGetThreadIdx(natp);
   NaClLog(2,
           "NaClTlsFree: old idx %d $tp %x\n",
-          idx, natp->user.r9);
+          idx, natp->user.t8);
 
   NaClXMutexLock(&gNaClTlsMu);
-  gNaClThreadIdxInUse[idx] = 0;
+  gNaClThreadIdxInUse[idx - 1] = 0;
   NaClXMutexUnlock(&gNaClTlsMu);
 
-  natp->user.r9 = 0;
+  natp->user.t8 = 0;
 }
 
 
 void NaClTlsChange(struct NaClAppThread *natp) {
   NaClLog(2, "NaClTlsChange: $tp %x\n", natp->tls_values.tls1);
 
-  natp->user.r9 = natp->tls_values.tls1;
+  natp->user.t8 = natp->tls_values.tls1;
 }