commit dd04c658c34c769107e13c106e0cd6df5d889da2
author Elliott Hughes <enh@google.com> Mon Apr 15 13:03:48 2019 -0700
committer Elliott Hughes <enh@google.com> Mon Apr 15 13:03:48 2019 -0700
tree fe28b685002b53a80911fc34d5759a0207686dc6
parent f14652c30b8140a6e14970adeda4912063ad22c3

crasher: add execute-only memory ("xom").

Test: `crasher thread-xom`
Change-Id: Ia121848df966040968370e1e9cb840034d780e4f

debuggerd/crasher/crasher.cpp

diff --git a/debuggerd/crasher/crasher.cpp b/debuggerd/crasher/crasher.cpp
index f0bdfbf..3041664 100644
--- a/debuggerd/crasher/crasher.cpp
+++ b/debuggerd/crasher/crasher.cpp
@@ -193,6 +193,7 @@
     fprintf(stderr, "  kuser_memory_barrier  call kuser_memory_barrier\n");
     fprintf(stderr, "  kuser_cmpxchg64       call kuser_cmpxchg64\n");
 #endif
+    fprintf(stderr, "  xom                   read execute-only memory\n");
     fprintf(stderr, "\n");
     fprintf(stderr, "  LOG_ALWAYS_FATAL      call liblog LOG_ALWAYS_FATAL\n");
     fprintf(stderr, "  LOG_ALWAYS_FATAL_IF   call liblog LOG_ALWAYS_FATAL_IF\n");
@@ -314,6 +315,11 @@
     } else if (!strcasecmp(arg, "seccomp")) {
       set_system_seccomp_filter();
       syscall(99999);
+#if defined(__LP64__)
+    } else if (!strcasecmp(arg, "xom")) {
+      // Try to read part of our code, which will fail if XOM is active.
+      printf("*%lx = %lx\n", reinterpret_cast<long>(usage), *reinterpret_cast<long*>(usage));
+#endif
 #if defined(__arm__)
     } else if (!strcasecmp(arg, "kuser_helper_version")) {
         return __kuser_helper_version;