compiler-rt/test/dfsan/mmap_at_init.c

   1 // RUN: %clang_dfsan -fno-sanitize=dataflow -DCALLOC -c %s -o %t-calloc.o
   2 // RUN: %clang_dfsan %s %t-calloc.o -o %t
   3 // RUN: %run %t
   4 //
   5 // Tests that calling mmap() during during dfsan initialization works.
   6
   7 #include <sanitizer/dfsan_interface.h>
   8 #include <sys/mman.h>
   9 #include <unistd.h>
  10
  11 #ifdef CALLOC
  12
  13 extern void exit(int) __attribute__((noreturn));
  14
  15 // dfsan_init() installs interceptors via dlysm(), which calls calloc().
  16 // Calling mmap() from here should work even if interceptors haven't been fully
  17 // set up yet.
  18 void *calloc(size_t Num, size_t Size) {
  19   size_t PageSize = getpagesize();
  20   Size = Size * Num;
  21   Size = (Size + PageSize - 1) & ~(PageSize - 1); // Round up to PageSize.
  22   void *Ret = mmap(NULL, Size, PROT_READ | PROT_WRITE,
  23                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  24   // Use assert may cause link errors that require -Wl,-z,notext.
  25   // Do not know the root cause yet.
  26   if (Ret == MAP_FAILED) exit(-1);
  27   return Ret;
  28 }
  29
  30 #else
  31
  32 int main() { return 0; }
  33
  34 #endif // CALLOC