Bug 1066760 - Use more detailed abort message on Android; r=snorp

memory/mozalloc/mozalloc_abort.cpp

@@ -16,6 +16,7 @@
 #endif
 #ifdef MOZ_WIDGET_ANDROID
 # include "APKOpen.h"
+# include "dlfcn.h"
 #endif
 #include <stdio.h>
 
@@ -36,13 +37,42 @@ mozalloc_abort(const char* const msg)
     MOZ_CRASH();
 }
 
+#ifdef MOZ_WIDGET_ANDROID
+template <size_t N>
+void fillAbortMessage(char (&msg)[N], uintptr_t retAddress) {
+    /*
+     * On Android, we often don't have reliable backtrace when crashing inside
+     * abort(). Therefore, we try to find out who is calling abort() and add
+     * that to the message.
+     */
+    Dl_info info = {};
+    dladdr(reinterpret_cast<void*>(retAddress), &info);
+
+    const char* const module = info.dli_fname ? info.dli_fname : "";
+    const char* const base_module = strrchr(module, '/');
+    const void* const module_offset =
+        reinterpret_cast<void*>(retAddress - uintptr_t(info.dli_fbase));
+    const char* const sym = info.dli_sname ? info.dli_sname : "";
+
+    snprintf(msg, sizeof(msg), "abort() called from %s:%p (%s)",
+             base_module ? base_module + 1 : module, module_offset, sym);
+}
+#endif
+
 #if defined(XP_UNIX)
 // Define abort() here, so that it is used instead of the system abort(). This
 // lets us control the behavior when aborting, in order to get better results
 // on *NIX platforms. See mozalloc_abort for details.
 void abort(void)
 {
-    mozalloc_abort("Redirecting call to abort() to mozalloc_abort\n");
+#ifdef MOZ_WIDGET_ANDROID
+    char msg[64] = {};
+    fillAbortMessage(msg, uintptr_t(__builtin_return_address(0)));
+#else
+    const char* const msg = "Redirecting call to abort() to mozalloc_abort\n";
+#endif
+
+    mozalloc_abort(msg);
 }
 #endif