In android_set_abort_message, check for nullptr.

If a process is failing due to out of memory, some code calls
android_set_abort_message with a nullptr. Specifically, the libc++
library std::terminate can call do this. In this case, put a
null in the abort message.

Test: Call with nullptr and verify the code does not crash.
Test: Modified crasher to set an abort message and set a null abort
Test: message. Ran both, verified the abort message displays in
Test: first case, and doesn't display in the second case.
Change-Id: Ia9250f47e4537853ce93bbb20b35915a78caa502

1 files changed, 4 insertions, 0 deletions

diff --git a/libc/bionic/android_set_abort_message.cpp b/libc/bionic/android_set_abort_message.cpp
index 2ea12ee54..d5f8cb97f 100644
--- a/libc/bionic/android_set_abort_message.cpp
+++ b/libc/bionic/android_set_abort_message.cpp
@@ -77,6 +77,10 @@ void android_set_abort_message(const char* msg) {
     return;
   }
 
+  if (msg == nullptr) {
+    msg = "(null)";
+  }
+
   size_t size = sizeof(magic_abort_msg_t) + strlen(msg) + 1;
   void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
   if (map == MAP_FAILED) {