[dfsan] Dfsan version of D113328

[vitalybuka]

Summary

Depends on D113328.

[vitalybuka]

rebase

[eugenis]

LGTM

[vitalybuka]

rebase

compiler-rt/lib/dfsan/dfsan_custom.cpp

SANITIZER_INTERFACE_ATTRIBUTE void *__dfso_dlopen(
     dfsan_origin *ret_origin) {
   return __dfsw_dlopen(filename, flag, filename_label, flag_label, ret_label);
 }
 
 static void *DFsanThreadStartFunc(void *arg) {
   DFsanThread *t = (DFsanThread *)arg;
   SetCurrentThread(t);
   t->Init();
+  SetSigProcMask(&t->starting_sigset_, nullptr);
   return t->ThreadStart();
 }
 
 static int dfsan_pthread_create(pthread_t *thread, const pthread_attr_t *attr,
                                 void *start_routine_trampoline,
                                 void *start_routine, void *arg,
                                 dfsan_label *ret_label,
                                 bool track_origins = false) {
   pthread_attr_t myattr;
   if (!attr) {
     pthread_attr_init(&myattr);
     attr = &myattr;
   }
 
   // Ensure that the thread stack is large enough to hold all TLS data.
   AdjustStackSize((void *)(const_cast<pthread_attr_t *>(attr)));
 
   DFsanThread *t =
       DFsanThread::Create(start_routine_trampoline,
                           (thread_callback_t)start_routine, arg, track_origins);
+  ScopedBlockSignals block(&t->starting_sigset_);
   int res = pthread_create(thread, attr, DFsanThreadStartFunc, t);
 
   if (attr == &myattr)
     pthread_attr_destroy(&myattr);
   *ret_label = 0;
   return res;
 }
 

compiler-rt/lib/dfsan/dfsan_thread.h

 //
 //===----------------------------------------------------------------------===//
 
 #ifndef DFSAN_THREAD_H
 #define DFSAN_THREAD_H
 
 #include "dfsan_allocator.h"
 #include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_posix.h"
 
 namespace __dfsan {
 
 class DFsanThread {
  public:
   // NOTE: There is no DFsanThread constructor. It is allocated
   // via mmap() and *must* be valid in zero-initialized state.
 
public:
 
   bool InSignalHandler() { return in_signal_handler_; }
   void EnterSignalHandler() { in_signal_handler_++; }
   void LeaveSignalHandler() { in_signal_handler_--; }
 
   DFsanThreadLocalMallocStorage &malloc_storage() { return malloc_storage_; }
 
   int destructor_iterations_;
+  __sanitizer_sigset_t starting_sigset_;
 
  private:
   void SetThreadStackAndTls();
   void ClearShadowForThreadStackAndTLS();
   struct StackBounds {
     uptr bottom;
     uptr top;
   };