Revert "[asan] Support running without /proc.", +1

Revert r350104 "[asan] Fix build on windows."
Revert r350101 "[asan] Support running without /proc."

These changes break Mac build, too.

llvm-svn: 350112

Author: eugenis

compiler-rt/lib/asan/asan_linux.cc

@@ -210,8 +210,6 @@ void AsanCheckIncompatibleRT() {
     }
   } else {
     if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
-      if (!MemoryMappingLayout::IsAvailable())
-        return;
       // 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

compiler-rt/lib/asan/asan_thread.cc

@@ -18,7 +18,6 @@
 #include "asan_thread.h"
 #include "asan_mapping.h"
 #include "sanitizer_common/sanitizer_common.h"
-#include "sanitizer_common/sanitizer_file.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
@@ -224,11 +223,9 @@ void AsanThread::Init(const InitOptions *options) {
   atomic_store(&stack_switching_, false, memory_order_release);
   CHECK_EQ(this->stack_size(), 0U);
   SetThreadStackAndTls(options);
-  if (stack_top_ != stack_bottom_) {
-    CHECK_GT(this->stack_size(), 0U);
-    CHECK(AddrIsInMem(stack_bottom_));
-    CHECK(AddrIsInMem(stack_top_ - 1));
-  }
+  CHECK_GT(this->stack_size(), 0U);
+  CHECK(AddrIsInMem(stack_bottom_));
+  CHECK(AddrIsInMem(stack_top_ - 1));
   ClearShadowForThreadStackAndTLS();
   fake_stack_ = nullptr;
   if (__asan_option_detect_stack_use_after_return)
@@ -285,42 +282,27 @@ AsanThread *CreateMainThread() {
   return main_thread;
 }
 
-static bool StackLimitsAreAvailable() {
-#if SANITIZER_WINDOWS
-  return true;
-#else
-  return MemoryMappingLayout::IsAvailable();
-#endif
-}
-
 // This implementation doesn't use the argument, which is just passed down
 // from the caller of Init (which see, above).  It's only there to support
 // OS-specific implementations that need more information passed through.
 void AsanThread::SetThreadStackAndTls(const InitOptions *options) {
   DCHECK_EQ(options, nullptr);
-  // If this process is "init" (pid 1), /proc may not be mounted yet.
-  if (!start_routine_ && !StackLimitsAreAvailable()) {
-    stack_top_ = stack_bottom_ = 0;
-    tls_begin_ = tls_end_ = 0;
-  } else {
-    uptr tls_size = 0;
-    uptr stack_size = 0;
-    GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size, &tls_begin_,
-                         &tls_size);
-    stack_top_ = stack_bottom_ + stack_size;
-    tls_end_ = tls_begin_ + tls_size;
-    dtls_ = DTLS_Get();
-
-    int local;
-    CHECK(AddrIsInStack((uptr)&local));
-  }
+  uptr tls_size = 0;
+  uptr stack_size = 0;
+  GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size, &tls_begin_,
+                       &tls_size);
+  stack_top_ = stack_bottom_ + stack_size;
+  tls_end_ = tls_begin_ + tls_size;
+  dtls_ = DTLS_Get();
+
+  int local;
+  CHECK(AddrIsInStack((uptr)&local));
 }
 
 #endif  // !SANITIZER_FUCHSIA && !SANITIZER_RTEMS
 
 void AsanThread::ClearShadowForThreadStackAndTLS() {
-  if (stack_top_ != stack_bottom_)
-    PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
+  PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
   if (tls_begin_ != tls_end_) {
     uptr tls_begin_aligned = RoundDownTo(tls_begin_, SHADOW_GRANULARITY);
     uptr tls_end_aligned = RoundUpTo(tls_end_, SHADOW_GRANULARITY);
@@ -332,9 +314,6 @@ void AsanThread::ClearShadowForThreadStackAndTLS() {
 
 bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
                                            StackFrameAccess *access) {
-  if (stack_top_ == stack_bottom_)
-    return false;
-
   uptr bottom = 0;
   if (AddrIsInStack(addr)) {
     bottom = stack_bottom();

compiler-rt/lib/hwasan/hwasan_thread.cc

@@ -44,7 +44,7 @@ void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size) {
   ScopedTaggingDisabler disabler;
 
   // If this process is "init" (pid 1), /proc may not be mounted yet.
-  if (IsMainThread() && !MemoryMappingLayout::IsAvailable()) {
+  if (IsMainThread() && !FileExists("/proc/self/maps")) {
     stack_top_ = stack_bottom_ = 0;
     tls_begin_ = tls_end_ = 0;
   } else {

compiler-rt/lib/sanitizer_common/sanitizer_flags.inc

@@ -243,6 +243,3 @@ COMMON_FLAG(bool, dump_registers, true,
 COMMON_FLAG(bool, detect_write_exec, false,
           "If true, triggers warning when writable-executable pages requests "
           "are being made")
-COMMON_FLAG(bool, test_only_emulate_no_procfs, false,
-            "TEST ONLY fail to open any files under /proc to emulate sanitized "
-            "\"init\"")

compiler-rt/lib/sanitizer_common/sanitizer_linux.cc

@@ -453,8 +453,6 @@ uptr internal_execve(const char *filename, char *const argv[],
 
 // ----------------- sanitizer_common.h
 bool FileExists(const char *filename) {
-  if (ShouldMockFailureToOpen(filename))
-    return false;
   struct stat st;
 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
   if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
@@ -1005,8 +1003,6 @@ ThreadLister::~ThreadLister() {
 // Take care of unusable kernel area in top gigabyte.
 static uptr GetKernelAreaSize() {
 #if SANITIZER_LINUX && !SANITIZER_X32
-  if (!MemoryMappingLayout::IsAvailable())
-    return 0;
   const uptr gbyte = 1UL << 30;
 
   // Firstly check if there are writable segments

compiler-rt/lib/sanitizer_common/sanitizer_linux.h

@@ -44,7 +44,6 @@ struct MemoryMappingLayoutData {
 };
 
 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
-bool IsProcMapsAvailable();
 
 // Syscall wrappers.
 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);

compiler-rt/lib/sanitizer_common/sanitizer_mac.cc

@@ -282,8 +282,6 @@ uptr internal_waitpid(int pid, int *status, int options) {
 
 // ----------------- sanitizer_common.h
 bool FileExists(const char *filename) {
-  if (ShouldMockFailureToOpen(filename))
-    return false;
   struct stat st;
   if (stat(filename, &st))
     return false;

compiler-rt/lib/sanitizer_common/sanitizer_posix.cc

@@ -18,7 +18,6 @@
 
 #include "sanitizer_common.h"
 #include "sanitizer_file.h"
-#include "sanitizer_flags.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_posix.h"
 #include "sanitizer_procmaps.h"
@@ -158,8 +157,6 @@ void MprotectMallocZones(void *addr, int prot) {}
 #endif
 
 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
-  if (ShouldMockFailureToOpen(filename))
-    return kInvalidFd;
   int flags;
   switch (mode) {
     case RdOnly: flags = O_RDONLY; break;
@@ -232,8 +229,6 @@ static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 // several worker threads on Mac, which aren't expected to map big chunks of
 // memory).
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
-  if (!MemoryMappingLayout::IsAvailable())
-    return true; // hope for the best
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
   MemoryMappedSegment segment;
   while (proc_maps.Next(&segment)) {
@@ -339,11 +334,6 @@ fd_t ReserveStandardFds(fd_t fd) {
   return fd;
 }
 
-bool ShouldMockFailureToOpen(const char *path) {
-  return common_flags()->test_only_emulate_no_procfs &&
-         internal_strncmp(path, "/proc/", 6) == 0;
-}
-
 } // namespace __sanitizer
 
 #endif // SANITIZER_POSIX

compiler-rt/lib/sanitizer_common/sanitizer_posix.h

@@ -103,8 +103,6 @@ bool IsStateDetached(int state);
 // Move the fd out of {0, 1, 2} range.
 fd_t ReserveStandardFds(fd_t fd);
 
-bool ShouldMockFailureToOpen(const char *path);
-
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_POSIX_H

compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h

@@ -75,7 +75,6 @@ class MemoryMappingLayout {
   // to obtain the memory mappings. It should fall back to pre-cached data
   // instead of aborting.
   static void CacheMemoryMappings();
-  static bool IsAvailable();
 
   // Adds all mapped objects into a vector.
   void DumpListOfModules(InternalMmapVectorNoCtor<LoadedModule> *modules);