Import compiler-rt r182741.vendor/compiler-rt/compiler-rt-r182741

1 files changed, 124 insertions, 174 deletions

diff --git a/lib/asan/asan_mac.cc b/lib/asan/asan_mac.cc
index 3ed9e06eeb6f..4313534008e7 100644
--- a/lib/asan/asan_mac.cc
+++ b/lib/asan/asan_mac.cc
@@ -12,7 +12,8 @@
 // Mac-specific details.
 //===----------------------------------------------------------------------===//
 
-#ifdef __APPLE__
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_MAC
 
 #include "asan_interceptors.h"
 #include "asan_internal.h"
@@ -20,7 +21,6 @@
 #include "asan_mapping.h"
 #include "asan_stack.h"
 #include "asan_thread.h"
-#include "asan_thread_registry.h"
 #include "sanitizer_common/sanitizer_libc.h"
 
 #include <crt_externs.h>  // for _NSGetArgv
@@ -36,7 +36,6 @@
 #include <stdlib.h>  // for free()
 #include <unistd.h>
 #include <libkern/OSAtomic.h>
-#include <CoreFoundation/CFString.h>
 
 namespace __asan {
 
@@ -59,9 +58,9 @@ int GetMacosVersion() {
   uptr len = 0, maxlen = sizeof(version) / sizeof(version[0]);
   for (uptr i = 0; i < maxlen; i++) version[i] = '\0';
   // Get the version length.
-  CHECK(sysctl(mib, 2, 0, &len, 0, 0) != -1);
-  CHECK(len < maxlen);
-  CHECK(sysctl(mib, 2, version, &len, 0, 0) != -1);
+  CHECK_NE(sysctl(mib, 2, 0, &len, 0, 0), -1);
+  CHECK_LT(len, maxlen);
+  CHECK_NE(sysctl(mib, 2, version, &len, 0, 0), -1);
   switch (version[0]) {
     case '9': return MACOS_VERSION_LEOPARD;
     case '1': {
@@ -89,16 +88,52 @@ extern "C"
 void __asan_init();
 
 static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES";
+LowLevelAllocator allocator_for_env;
+
+// Change the value of the env var |name|, leaking the original value.
+// If |name_value| is NULL, the variable is deleted from the environment,
+// otherwise the corresponding "NAME=value" string is replaced with
+// |name_value|.
+void LeakyResetEnv(const char *name, const char *name_value) {
+  char ***env_ptr = _NSGetEnviron();
+  CHECK(env_ptr);
+  char **environ = *env_ptr;
+  CHECK(environ);
+  uptr name_len = internal_strlen(name);
+  while (*environ != 0) {
+    uptr len = internal_strlen(*environ);
+    if (len > name_len) {
+      const char *p = *environ;
+      if (!internal_memcmp(p, name, name_len) && p[name_len] == '=') {
+        // Match.
+        if (name_value) {
+          // Replace the old value with the new one.
+          *environ = const_cast<char*>(name_value);
+        } else {
+          // Shift the subsequent pointers back.
+          char **del = environ;
+          do {
+            del[0] = del[1];
+          } while (*del++);
+        }
+      }
+    }
+    environ++;
+  }
+}
 
 void MaybeReexec() {
   if (!flags()->allow_reexec) return;
-#if MAC_INTERPOSE_FUNCTIONS
-  // If the program is linked with the dynamic ASan runtime library, make sure
-  // the library is preloaded so that the wrappers work. If it is not, set
-  // DYLD_INSERT_LIBRARIES and re-exec ourselves.
+  // Make sure the dynamic ASan runtime library is preloaded so that the
+  // wrappers work. If it is not, set DYLD_INSERT_LIBRARIES and re-exec
+  // ourselves.
   Dl_info info;
   CHECK(dladdr((void*)((uptr)__asan_init), &info));
-  const char *dyld_insert_libraries = GetEnv(kDyldInsertLibraries);
+  char *dyld_insert_libraries =
+      const_cast<char*>(GetEnv(kDyldInsertLibraries));
+  uptr old_env_len = dyld_insert_libraries ?
+      internal_strlen(dyld_insert_libraries) : 0;
+  uptr fname_len = internal_strlen(info.dli_fname);
   if (!dyld_insert_libraries ||
       !REAL(strstr)(dyld_insert_libraries, info.dli_fname)) {
     // DYLD_INSERT_LIBRARIES is not set or does not contain the runtime
@@ -106,19 +141,80 @@ void MaybeReexec() {
     char program_name[1024];
     uint32_t buf_size = sizeof(program_name);
     _NSGetExecutablePath(program_name, &buf_size);
-    // Ok to use setenv() since the wrappers don't depend on the value of
-    // asan_inited.
-    setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0);
+    char *new_env = const_cast<char*>(info.dli_fname);
+    if (dyld_insert_libraries) {
+      // Append the runtime dylib name to the existing value of
+      // DYLD_INSERT_LIBRARIES.
+      new_env = (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2);
+      internal_strncpy(new_env, dyld_insert_libraries, old_env_len);
+      new_env[old_env_len] = ':';
+      // Copy fname_len and add a trailing zero.
+      internal_strncpy(new_env + old_env_len + 1, info.dli_fname,
+                       fname_len + 1);
+      // Ok to use setenv() since the wrappers don't depend on the value of
+      // asan_inited.
+      setenv(kDyldInsertLibraries, new_env, /*overwrite*/1);
+    } else {
+      // Set DYLD_INSERT_LIBRARIES equal to the runtime dylib name.
+      setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0);
+    }
     if (flags()->verbosity >= 1) {
       Report("exec()-ing the program with\n");
-      Report("%s=%s\n", kDyldInsertLibraries, info.dli_fname);
+      Report("%s=%s\n", kDyldInsertLibraries, new_env);
       Report("to enable ASan wrappers.\n");
       Report("Set ASAN_OPTIONS=allow_reexec=0 to disable this.\n");
     }
     execv(program_name, *_NSGetArgv());
+  } else {
+    // DYLD_INSERT_LIBRARIES is set and contains the runtime library.
+    if (old_env_len == fname_len) {
+      // It's just the runtime library name - fine to unset the variable.
+      LeakyResetEnv(kDyldInsertLibraries, NULL);
+    } else {
+      uptr env_name_len = internal_strlen(kDyldInsertLibraries);
+      // Allocate memory to hold the previous env var name, its value, the '='
+      // sign and the '\0' char.
+      char *new_env = (char*)allocator_for_env.Allocate(
+          old_env_len + 2 + env_name_len);
+      CHECK(new_env);
+      internal_memset(new_env, '\0', old_env_len + 2 + env_name_len);
+      internal_strncpy(new_env, kDyldInsertLibraries, env_name_len);
+      new_env[env_name_len] = '=';
+      char *new_env_pos = new_env + env_name_len + 1;
+
+      // Iterate over colon-separated pieces of |dyld_insert_libraries|.
+      char *piece_start = dyld_insert_libraries;
+      char *piece_end = NULL;
+      char *old_env_end = dyld_insert_libraries + old_env_len;
+      do {
+        if (piece_start[0] == ':') piece_start++;
+        piece_end =  REAL(strchr)(piece_start, ':');
+        if (!piece_end) piece_end = dyld_insert_libraries + old_env_len;
+        if ((uptr)(piece_start - dyld_insert_libraries) > old_env_len) break;
+        uptr piece_len = piece_end - piece_start;
+
+        // If the current piece isn't the runtime library name,
+        // append it to new_env.
+        if ((piece_len != fname_len) ||
+            (internal_strncmp(piece_start, info.dli_fname, fname_len) != 0)) {
+          if (new_env_pos != new_env + env_name_len + 1) {
+            new_env_pos[0] = ':';
+            new_env_pos++;
+          }
+          internal_strncpy(new_env_pos, piece_start, piece_len);
+        }
+        // Move on to the next piece.
+        new_env_pos += piece_len;
+        piece_start = piece_end;
+      } while (piece_start < old_env_end);
+
+      // Can't use setenv() here, because it requires the allocator to be
+      // initialized.
+      // FIXME: instead of filtering DYLD_INSERT_LIBRARIES here, do it in
+      // a separate function called after InitializeAllocator().
+      LeakyResetEnv(kDyldInsertLibraries, new_env);
+    }
   }
-#endif  // MAC_INTERPOSE_FUNCTIONS
-  // If we're not using the dynamic runtime, do nothing.
 }
 
 // No-op. Mac does not support static linkage anyway.
@@ -131,83 +227,12 @@ bool AsanInterceptsSignal(int signum) {
 }
 
 void AsanPlatformThreadInit() {
-  // For the first program thread, we can't replace the allocator before
-  // __CFInitialize() has been called. If it hasn't, we'll call
-  // MaybeReplaceCFAllocator() later on this thread.
-  // For other threads __CFInitialize() has been called before their creation.
-  // See also asan_malloc_mac.cc.
-  if (((CFRuntimeBase*)kCFAllocatorSystemDefault)->_cfisa) {
-    MaybeReplaceCFAllocator();
-  }
-}
-
-void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp, bool fast) {
-  (void)fast;
-  stack->size = 0;
-  stack->trace[0] = pc;
-  if ((max_s) > 1) {
-    stack->max_size = max_s;
-    if (!asan_inited) return;
-    if (AsanThread *t = asanThreadRegistry().GetCurrent())
-      stack->FastUnwindStack(pc, bp, t->stack_top(), t->stack_bottom());
-  }
 }
 
 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
   UNIMPLEMENTED();
 }
 
-// The range of pages to be used for escape islands.
-// TODO(glider): instead of mapping a fixed range we must find a range of
-// unmapped pages in vmmap and take them.
-// These constants were chosen empirically and may not work if the shadow
-// memory layout changes. Unfortunately they do necessarily depend on
-// kHighMemBeg or kHighMemEnd.
-static void *island_allocator_pos = 0;
-
-#if SANITIZER_WORDSIZE == 32
-# define kIslandEnd (0xffdf0000 - GetPageSizeCached())
-# define kIslandBeg (kIslandEnd - 256 * GetPageSizeCached())
-#else
-# define kIslandEnd (0x7fffffdf0000 - GetPageSizeCached())
-# define kIslandBeg (kIslandEnd - 256 * GetPageSizeCached())
-#endif
-
-extern "C"
-mach_error_t __interception_allocate_island(void **ptr,
-                                            uptr unused_size,
-                                            void *unused_hint) {
-  if (!island_allocator_pos) {
-    island_allocator_pos =
-        internal_mmap((void*)kIslandBeg, kIslandEnd - kIslandBeg,
-                      PROT_READ | PROT_WRITE | PROT_EXEC,
-                      MAP_PRIVATE | MAP_ANON | MAP_FIXED,
-                      -1, 0);
-    if (island_allocator_pos != (void*)kIslandBeg) {
-      return KERN_NO_SPACE;
-    }
-    if (flags()->verbosity) {
-      Report("Mapped pages %p--%p for branch islands.\n",
-             (void*)kIslandBeg, (void*)kIslandEnd);
-    }
-    // Should not be very performance-critical.
-    internal_memset(island_allocator_pos, 0xCC, kIslandEnd - kIslandBeg);
-  };
-  *ptr = island_allocator_pos;
-  island_allocator_pos = (char*)island_allocator_pos + GetPageSizeCached();
-  if (flags()->verbosity) {
-    Report("Branch island allocated at %p\n", *ptr);
-  }
-  return err_none;
-}
-
-extern "C"
-mach_error_t __interception_deallocate_island(void *ptr) {
-  // Do nothing.
-  // TODO(glider): allow to free and reuse the island memory.
-  return err_none;
-}
-
 // Support for the following functions from libdispatch on Mac OS:
 //   dispatch_async_f()
 //   dispatch_async()
@@ -237,9 +262,6 @@ mach_error_t __interception_deallocate_island(void *ptr) {
 // The implementation details are at
 //   http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c
 
-typedef void* pthread_workqueue_t;
-typedef void* pthread_workitem_handle_t;
-
 typedef void* dispatch_group_t;
 typedef void* dispatch_queue_t;
 typedef void* dispatch_source_t;
@@ -254,32 +276,16 @@ typedef struct {
   u32 parent_tid;
 } asan_block_context_t;
 
-// We use extern declarations of libdispatch functions here instead
-// of including <dispatch/dispatch.h>. This header is not present on
-// Mac OS X Leopard and eariler, and although we don't expect ASan to
-// work on legacy systems, it's bad to break the build of
-// LLVM compiler-rt there.
-extern "C" {
-void dispatch_async_f(dispatch_queue_t dq, void *ctxt,
-                      dispatch_function_t func);
-void dispatch_sync_f(dispatch_queue_t dq, void *ctxt,
-                     dispatch_function_t func);
-void dispatch_after_f(dispatch_time_t when, dispatch_queue_t dq, void *ctxt,
-                      dispatch_function_t func);
-void dispatch_barrier_async_f(dispatch_queue_t dq, void *ctxt,
-                              dispatch_function_t func);
-void dispatch_group_async_f(dispatch_group_t group, dispatch_queue_t dq,
-                            void *ctxt, dispatch_function_t func);
-}  // extern "C"
-
-static ALWAYS_INLINE
+ALWAYS_INLINE
 void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
-  AsanThread *t = asanThreadRegistry().GetCurrent();
+  AsanThread *t = GetCurrentThread();
   if (!t) {
-    t = AsanThread::Create(parent_tid, 0, 0, stack);
-    asanThreadRegistry().RegisterThread(t);
+    t = AsanThread::Create(0, 0);
+    CreateThreadContextArgs args = { t, stack };
+    asanThreadRegistry().CreateThread(*(uptr*)t, true, parent_tid, &args);
     t->Init();
-    asanThreadRegistry().SetCurrent(t);
+    asanThreadRegistry().StartThread(t->tid(), 0, 0);
+    SetCurrentThread(t);
   }
 }
 
@@ -313,7 +319,7 @@ asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func,
       (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack);
   asan_ctxt->block = ctxt;
   asan_ctxt->func = func;
-  asan_ctxt->parent_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
+  asan_ctxt->parent_tid = GetCurrentTidOrInvalid();
   return asan_ctxt;
 }
 
@@ -364,14 +370,7 @@ INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
                                asan_dispatch_call_block_and_release);
 }
 
-#if MAC_INTERPOSE_FUNCTIONS && !defined(MISSING_BLOCKS_SUPPORT)
-// dispatch_async, dispatch_group_async and others tailcall the corresponding
-// dispatch_*_f functions. When wrapping functions with mach_override, those
-// dispatch_*_f are intercepted automatically. But with dylib interposition
-// this does not work, because the calls within the same library are not
-// interposed.
-// Therefore we need to re-implement dispatch_async and friends.
-
+#if !defined(MISSING_BLOCKS_SUPPORT)
 extern "C" {
 // FIXME: consolidate these declarations with asan_intercepted_functions.h.
 void dispatch_async(dispatch_queue_t dq, void(^work)(void));
@@ -386,7 +385,7 @@ void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void));
 
 #define GET_ASAN_BLOCK(work) \
   void (^asan_block)(void);  \
-  int parent_tid = asanThreadRegistry().GetCurrentTidOrInvalid(); \
+  int parent_tid = GetCurrentTidOrInvalid(); \
   asan_block = ^(void) { \
     GET_STACK_TRACE_THREAD; \
     asan_register_worker_thread(parent_tid, &stack); \
@@ -424,53 +423,4 @@ INTERCEPTOR(void, dispatch_source_set_event_handler,
 }
 #endif
 
-// See http://opensource.apple.com/source/CF/CF-635.15/CFString.c
-int __CFStrIsConstant(CFStringRef str) {
-  CFRuntimeBase *base = (CFRuntimeBase*)str;
-#if __LP64__
-  return base->_rc == 0;
-#else
-  return (base->_cfinfo[CF_RC_BITS]) == 0;
-#endif
-}
-
-INTERCEPTOR(CFStringRef, CFStringCreateCopy, CFAllocatorRef alloc,
-                                             CFStringRef str) {
-  if (__CFStrIsConstant(str)) {
-    return str;
-  } else {
-    return REAL(CFStringCreateCopy)(alloc, str);
-  }
-}
-
-DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
-
-DECLARE_REAL_AND_INTERCEPTOR(void, __CFInitialize, void)
-
-namespace __asan {
-
-void InitializeMacInterceptors() {
-  CHECK(INTERCEPT_FUNCTION(dispatch_async_f));
-  CHECK(INTERCEPT_FUNCTION(dispatch_sync_f));
-  CHECK(INTERCEPT_FUNCTION(dispatch_after_f));
-  CHECK(INTERCEPT_FUNCTION(dispatch_barrier_async_f));
-  CHECK(INTERCEPT_FUNCTION(dispatch_group_async_f));
-  // Normally CFStringCreateCopy should not copy constant CF strings.
-  // Replacing the default CFAllocator causes constant strings to be copied
-  // rather than just returned, which leads to bugs in big applications like
-  // Chromium and WebKit, see
-  // http://code.google.com/p/address-sanitizer/issues/detail?id=10
-  // Until this problem is fixed we need to check that the string is
-  // non-constant before calling CFStringCreateCopy.
-  CHECK(INTERCEPT_FUNCTION(CFStringCreateCopy));
-  // Some of the library functions call free() directly, so we have to
-  // intercept it.
-  CHECK(INTERCEPT_FUNCTION(free));
-  if (flags()->replace_cfallocator) {
-    CHECK(INTERCEPT_FUNCTION(__CFInitialize));
-  }
-}
-
-}  // namespace __asan
-
-#endif  // __APPLE__
+#endif  // SANITIZER_MAC