commit 1f936a81eb45373bb768192793dc5d371d170e27
author David Carlier <devnexen@gmail.com> Thu Aug 22 21:36:35 2019 +0000
committer David Carlier <devnexen@gmail.com> Thu Aug 22 21:36:35 2019 +0000
tree b9607031aab54c83182300b1f5fc7dd093bfdfd8
parent cf80106b1322de3c43ac1c0c8605b4a0db6f0b8d

[Sanitizer] checks ASLR on FreeBSD

- Especially MemorySanitizer fails if those sysctl configs are enabled.

Reviewers: vitalybuka, emaste, dim

Reviewed By: dim

Differential Revision: https://reviews.llvm.org/D66582

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@369708 91177308-0d34-0410-b5e6-96231b3b80d8

lib/asan/asan_rtl.cpp

diff --git a/lib/asan/asan_rtl.cpp b/lib/asan/asan_rtl.cpp
index b16ca95..f720126 100644
--- a/lib/asan/asan_rtl.cpp
+++ b/lib/asan/asan_rtl.cpp
@@ -402,7 +402,6 @@
   asan_init_is_running = true;
 
   CacheBinaryName();
-  CheckASLR();
 
   // Initialize flags. This must be done early, because most of the
   // initialization steps look at flags().
@@ -450,6 +449,7 @@
   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 
   InitializeAsanInterceptors();
+  CheckASLR();
 
   // Enable system log ("adb logcat") on Android.
   // Doing this before interceptors are initialized crashes in:

lib/msan/msan.cpp

diff --git a/lib/msan/msan.cpp b/lib/msan/msan.cpp
index 1bc505e..f5b05c4 100644
--- a/lib/msan/msan.cpp
+++ b/lib/msan/msan.cpp
@@ -403,7 +403,6 @@
   AvoidCVE_2016_2143();
 
   CacheBinaryName();
-  CheckASLR();
   InitializeFlags();
 
   // Install tool-specific callbacks in sanitizer_common.
@@ -412,6 +411,7 @@
   __sanitizer_set_report_path(common_flags()->log_path);
 
   InitializeInterceptors();
+  CheckASLR();
   InitTlsSize();
   InstallDeadlySignalHandlers(MsanOnDeadlySignal);
   InstallAtExitHandler(); // Needs __cxa_atexit interceptor.

lib/sanitizer_common/sanitizer_linux.cpp

diff --git a/lib/sanitizer_common/sanitizer_linux.cpp b/lib/sanitizer_common/sanitizer_linux.cpp
index 1ed6af3..01be223 100644
--- a/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/lib/sanitizer_common/sanitizer_linux.cpp
@@ -2011,6 +2011,33 @@
     CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
     ReExec();
   }
+#elif SANITIZER_FREEBSD
+  int aslr_pie;
+  uptr len = sizeof(aslr_pie);
+#if SANITIZER_WORDSIZE == 64
+  if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable",
+      &aslr_pie, &len, NULL, 0) == -1)) {
+    // We're making things less 'dramatic' here since
+    // the OID is not necessarily guaranteed to be here
+    // just yet regarding FreeBSD release
+    return;
+  }
+
+  if (aslr_pie > 0) {
+    Printf("This sanitizer is not compatible with enabled ASLR and binaries compiled with PIE\n");
+    Die();
+  }
+#endif
+  // there might be 32 bits compat for 64 bits
+  if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable",
+      &aslr_pie, &len, NULL, 0) == -1)) {
+    return;
+  }
+
+  if (aslr_pie > 0) {
+    Printf("This sanitizer is not compatible with enabled ASLR and binaries compiled with PIE\n");
+    Die();
+  }
 #else
   // Do nothing
 #endif