1 files changed, 134 insertions, 15 deletions

diff --git a/libsanitizer/asan/asan_linux.cc b/libsanitizer/asan/asan_linux.cc
index 0692eb1f455..c504168b614 100644
--- a/libsanitizer/asan/asan_linux.cc
+++ b/libsanitizer/asan/asan_linux.cc
@@ -11,11 +11,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
-#if SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX
 
 #include "asan_interceptors.h"
 #include "asan_internal.h"
 #include "asan_thread.h"
+#include "sanitizer_common/sanitizer_flags.h"
+#include "sanitizer_common/sanitizer_freebsd.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_procmaps.h"
 
@@ -24,18 +26,43 @@
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
+#include <dlfcn.h>
 #include <fcntl.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <unwind.h>
 
-#if !SANITIZER_ANDROID
-// FIXME: where to get ucontext on Android?
-#include <sys/ucontext.h>
+#if SANITIZER_FREEBSD
+#include <sys/link_elf.h>
 #endif
 
+#if SANITIZER_ANDROID || SANITIZER_FREEBSD
+#include <ucontext.h>
 extern "C" void* _DYNAMIC;
+#else
+#include <sys/ucontext.h>
+#include <link.h>
+#endif
+
+// x86-64 FreeBSD 9.2 and older define 'ucontext_t' incorrectly in
+// 32-bit mode.
+#if SANITIZER_FREEBSD && (SANITIZER_WORDSIZE == 32) && \
+  __FreeBSD_version <= 902001  // v9.2
+#define ucontext_t xucontext_t
+#endif
+
+typedef enum {
+  ASAN_RT_VERSION_UNDEFINED = 0,
+  ASAN_RT_VERSION_DYNAMIC,
+  ASAN_RT_VERSION_STATIC,
+} asan_rt_version_t;
+
+// FIXME: perhaps also store abi version here?
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+asan_rt_version_t  __asan_rt_version;
+}
 
 namespace __asan {
 
@@ -48,38 +75,126 @@ void *AsanDoesNotSupportStaticLinkage() {
   return &_DYNAMIC;  // defined in link.h
 }
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 #if SANITIZER_ANDROID
-  *pc = *sp = *bp = 0;
-#elif defined(__arm__)
+// FIXME: should we do anything for Android?
+void AsanCheckDynamicRTPrereqs() {}
+void AsanCheckIncompatibleRT() {}
+#else
+static int FindFirstDSOCallback(struct dl_phdr_info *info, size_t size,
+                                void *data) {
+  // Continue until the first dynamic library is found
+  if (!info->dlpi_name || info->dlpi_name[0] == 0)
+    return 0;
+
+  // Ignore vDSO
+  if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
+    return 0;
+
+  *(const char **)data = info->dlpi_name;
+  return 1;
+}
+
+static bool IsDynamicRTName(const char *libname) {
+  return internal_strstr(libname, "libclang_rt.asan") ||
+    internal_strstr(libname, "libasan.so");
+}
+
+static void ReportIncompatibleRT() {
+  Report("Your application is linked against incompatible ASan runtimes.\n");
+  Die();
+}
+
+void AsanCheckDynamicRTPrereqs() {
+  // Ensure that dynamic RT is the first DSO in the list
+  const char *first_dso_name = 0;
+  dl_iterate_phdr(FindFirstDSOCallback, &first_dso_name);
+  if (first_dso_name && !IsDynamicRTName(first_dso_name)) {
+    Report("ASan runtime does not come first in initial library list; "
+           "you should either link runtime to your application or "
+           "manually preload it with LD_PRELOAD.\n");
+    Die();
+  }
+}
+
+void AsanCheckIncompatibleRT() {
+  if (ASAN_DYNAMIC) {
+    if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
+      __asan_rt_version = ASAN_RT_VERSION_DYNAMIC;
+    } else if (__asan_rt_version != ASAN_RT_VERSION_DYNAMIC) {
+      ReportIncompatibleRT();
+    }
+  } else {
+    if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
+      // Ensure that dynamic runtime is not present. We should detect it
+      // as early as possible, otherwise ASan interceptors could bind to
+      // the functions in dynamic ASan runtime instead of the functions in
+      // system libraries, causing crashes later in ASan initialization.
+      MemoryMappingLayout proc_maps(/*cache_enabled*/true);
+      char filename[128];
+      while (proc_maps.Next(0, 0, 0, filename, sizeof(filename), 0)) {
+        if (IsDynamicRTName(filename)) {
+          Report("Your application is linked against "
+                 "incompatible ASan runtimes.\n");
+          Die();
+        }
+      }
+      __asan_rt_version = ASAN_RT_VERSION_STATIC;
+    } else if (__asan_rt_version != ASAN_RT_VERSION_STATIC) {
+      ReportIncompatibleRT();
+    }
+  }
+}
+#endif  // SANITIZER_ANDROID
+
+void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
+#if defined(__arm__)
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.arm_pc;
   *bp = ucontext->uc_mcontext.arm_fp;
   *sp = ucontext->uc_mcontext.arm_sp;
-# elif defined(__hppa__)
+#elif defined(__aarch64__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.pc;
+  *bp = ucontext->uc_mcontext.regs[29];
+  *sp = ucontext->uc_mcontext.sp;
+#elif defined(__hppa__)
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.sc_iaoq[0];
   /* GCC uses %r3 whenever a frame pointer is needed.  */
   *bp = ucontext->uc_mcontext.sc_gr[3];
   *sp = ucontext->uc_mcontext.sc_gr[30];
-# elif defined(__x86_64__)
+#elif defined(__x86_64__)
+# if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.mc_rip;
+  *bp = ucontext->uc_mcontext.mc_rbp;
+  *sp = ucontext->uc_mcontext.mc_rsp;
+# else
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.gregs[REG_RIP];
   *bp = ucontext->uc_mcontext.gregs[REG_RBP];
   *sp = ucontext->uc_mcontext.gregs[REG_RSP];
-# elif defined(__i386__)
+# endif
+#elif defined(__i386__)
+# if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.mc_eip;
+  *bp = ucontext->uc_mcontext.mc_ebp;
+  *sp = ucontext->uc_mcontext.mc_esp;
+# else
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.gregs[REG_EIP];
   *bp = ucontext->uc_mcontext.gregs[REG_EBP];
   *sp = ucontext->uc_mcontext.gregs[REG_ESP];
-# elif defined(__powerpc__) || defined(__powerpc64__)
+# endif
+#elif defined(__powerpc__) || defined(__powerpc64__)
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.regs->nip;
   *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
   // The powerpc{,64}-linux ABIs do not specify r31 as the frame
   // pointer, but GCC always uses r31 when we need a frame pointer.
   *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
-# elif defined(__sparc__)
+#elif defined(__sparc__)
   ucontext_t *ucontext = (ucontext_t*)context;
   uptr *stk_ptr;
 # if defined (__arch64__)
@@ -93,7 +208,7 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   stk_ptr = (uptr *) *sp;
   *bp = stk_ptr[15];
 # endif
-# elif defined(__mips__)
+#elif defined(__mips__)
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.gregs[31];
   *bp = ucontext->uc_mcontext.gregs[30];
@@ -104,7 +219,7 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 }
 
 bool AsanInterceptsSignal(int signum) {
-  return signum == SIGSEGV && flags()->handle_segv;
+  return signum == SIGSEGV && common_flags()->handle_segv;
 }
 
 void AsanPlatformThreadInit() {
@@ -123,6 +238,10 @@ void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
 }
 #endif
 
+void *AsanDlSymNext(const char *sym) {
+  return dlsym(RTLD_NEXT, sym);
+}
+
 }  // namespace __asan
 
-#endif  // SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX