[sanitizer] Don't call task_for_pid(mach_task_self). NFC.

[kubamracek]

Summary

Calling task_for_pid with mach_task_self is just returning mach_task_self anyway, but it also triggers system warnings (task_for_pid is only supposed to be used by high-privileged executables). NFC.

rdar://problem/39198248

lib/lsan/lsan_common_mac.cc

for (const __sanitizer::LoadedModule::AddressRange &range :
       }
 
       ScanGlobalRange(range.beg, range.end, frontier);
     }
   }
 }
 
 void ProcessPlatformSpecificAllocations(Frontier *frontier) {
-  mach_port_name_t port;
-  if (task_for_pid(mach_task_self(), internal_getpid(), &port)
-      != KERN_SUCCESS) {
-    return;
-  }
-
   unsigned depth = 1;
   vm_size_t size = 0;
   vm_address_t address = 0;
   kern_return_t err = KERN_SUCCESS;
   mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
 
   InternalMmapVector<RootRegion> const *root_regions = GetRootRegions();
 
   while (err == KERN_SUCCESS) {
     struct vm_region_submap_info_64 info;
-    err = vm_region_recurse_64(port, &address, &size, &depth,
+    err = vm_region_recurse_64(mach_task_self(), &address, &size, &depth,
                                (vm_region_info_t)&info, &count);
 
     uptr end_address = address + size;
 
     // libxpc stashes some pointers in the Kernel Alloc Once page,
     // make sure not to report those as leaks.
     if (info.user_tag == kSanitizerVmMemoryOsAllocOnce) {
       ScanRangeForPointers(address, end_address, frontier, "GLOBAL",

lib/sanitizer_common/sanitizer_procmaps_mac.cc

 
 // _dyld_get_image_header() and related APIs don't report dyld itself.
 // We work around this by manually recursing through the memory map
 // until we hit a Mach header matching dyld instead. These recurse
 // calls are expensive, but the first memory map generation occurs
 // early in the process, when dyld is one of the only images loaded,
 // so it will be hit after only a few iterations.
 static mach_header *get_dyld_image_header() {
-  mach_port_name_t port;
-  if (task_for_pid(mach_task_self(), internal_getpid(), &port) !=
-      KERN_SUCCESS) {
-    return nullptr;
-  }
-
   unsigned depth = 1;
   vm_size_t size = 0;
   vm_address_t address = 0;
   kern_return_t err = KERN_SUCCESS;
   mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
 
   while (true) {
     struct vm_region_submap_info_64 info;
-    err = vm_region_recurse_64(port, &address, &size, &depth,
+    err = vm_region_recurse_64(mach_task_self(), &address, &size, &depth,
                                (vm_region_info_t)&info, &count);
     if (err != KERN_SUCCESS) return nullptr;
 
     if (size >= sizeof(mach_header) && info.protection & kProtectionRead) {
       mach_header *hdr = (mach_header *)address;
       if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) &&
           hdr->filetype == MH_DYLINKER) {
         return hdr;