[asan] don't crash if /proc/self/maps has enormous size (linux)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@149944 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_linux.cc b/lib/asan/asan_linux.cc
index cf1e6ab..01a019e 100644
--- a/lib/asan/asan_linux.cc
+++ b/lib/asan/asan_linux.cc
@@ -131,7 +131,7 @@
     inited = true;
     size_t environ_size;
     len = ReadFileToBuffer("/proc/self/environ",
-                           &environ, &environ_size, 1 << 20);
+                           &environ, &environ_size, 1 << 26);
   }
   if (!environ || len == 0) return NULL;
   size_t namelen = internal_strlen(name);
@@ -160,7 +160,7 @@
 AsanProcMaps::AsanProcMaps() {
   proc_self_maps_buff_len_ =
       ReadFileToBuffer("/proc/self/maps", &proc_self_maps_buff_,
-                       &proc_self_maps_buff_mmaped_size_, 1 << 20);
+                       &proc_self_maps_buff_mmaped_size_, 1 << 26);
   CHECK(proc_self_maps_buff_len_ > 0);
   // AsanWrite(2, proc_self_maps_buff_, proc_self_maps_buff_len_);
   Reset();