Revert "Add dyld to sanitizer procmaps on darwin"

This breaks several tests because we don't always have
access to __cxa_guard functions

This reverts commit 45eb470c3e9e8f6993a204e247c33d4092237efe.

llvm-svn: 302693

compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h

@@ -70,7 +70,6 @@ class MemoryMappingLayout {
   bool NextSegmentLoad(uptr *start, uptr *end, uptr *offset, char filename[],
                        uptr filename_size, ModuleArch *arch, u8 *uuid,
                        uptr *protection);
-  void GetSegmentAddrRange(uptr *start, uptr *end, uptr vmaddr, uptr vmsize);
   int current_image_;
   u32 current_magic_;
   u32 current_filetype_;

compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc

@@ -18,7 +18,6 @@
 
 #include <mach-o/dyld.h>
 #include <mach-o/loader.h>
-#include <mach/mach.h>
 
 // These are not available in older macOS SDKs.
 #ifndef CPU_SUBTYPE_X86_64_H
@@ -72,9 +71,6 @@ void MemoryMappingLayout::Reset() {
   internal_memset(current_uuid_, 0, kModuleUUIDSize);
 }
 
-static const char kDyldPath[] = "/usr/lib/dyld";
-static const int kDyldImageIdx = -1;
-
 // static
 void MemoryMappingLayout::CacheMemoryMappings() {
   // No-op on Mac for now.
@@ -99,12 +95,14 @@ bool MemoryMappingLayout::NextSegmentLoad(uptr *start, uptr *end, uptr *offset,
   const char *lc = current_load_cmd_addr_;
   current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize;
   if (((const load_command *)lc)->cmd == kLCSegment) {
+    const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
     const SegmentCommand* sc = (const SegmentCommand *)lc;
-    GetSegmentAddrRange(start, end, sc->vmaddr, sc->vmsize);
+    if (start) *start = sc->vmaddr + dlloff;
     if (protection) {
       // Return the initial protection.
       *protection = sc->initprot;
     }
+    if (end) *end = sc->vmaddr + sc->vmsize + dlloff;
     if (offset) {
       if (current_filetype_ == /*MH_EXECUTE*/ 0x2) {
         *offset = sc->vmaddr;
@@ -113,12 +111,8 @@ bool MemoryMappingLayout::NextSegmentLoad(uptr *start, uptr *end, uptr *offset,
       }
     }
     if (filename) {
-      if (current_image_ == kDyldImageIdx) {
-        internal_strncpy(filename, kDyldPath, filename_size);
-      } else {
-        internal_strncpy(filename, _dyld_get_image_name(current_image_),
-                         filename_size);
-      }
+      internal_strncpy(filename, _dyld_get_image_name(current_image_),
+                       filename_size);
     }
     if (arch) {
       *arch = current_arch_;
@@ -186,77 +180,11 @@ static bool IsModuleInstrumented(const load_command *first_lc) {
   return false;
 }
 
-// _dyld_get_image_header() and related APIs don't report dyld itself.
-// We work around this by manually recursing through the memory map
-// until we hit a Mach header matching dyld instead. These recurse
-// calls are expensive, but the first memory map generation occurs
-// early in the process, when dyld is one of the only images loaded,
-// so it will be hit after only a few iterations.
-static const struct mach_header *get_dyld_image_header() {
-  mach_port_name_t port;
-  if (task_for_pid(mach_task_self(), internal_getpid(), &port) !=
-      KERN_SUCCESS) {
-    return nullptr;
-  }
-
-  unsigned depth = 1;
-  vm_size_t size = 0;
-  vm_address_t address = 0;
-  kern_return_t err = KERN_SUCCESS;
-  mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
-
-  while (true) {
-    struct vm_region_submap_info_64 info;
-    err = vm_region_recurse_64(port, &address, &size, &depth,
-                               (vm_region_info_t)&info, &count);
-    if (err != KERN_SUCCESS) return nullptr;
-
-    if (size >= sizeof(struct mach_header) &&
-        info.protection & MemoryMappingLayout::kProtectionRead) {
-      struct mach_header *hdr = (struct mach_header *)address;
-      if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) &&
-          hdr->filetype == MH_DYLINKER) {
-        return hdr;
-      }
-    }
-    address += size;
-  }
-}
-
-// The dyld load address should be unchanged throughout process execution,
-// and it is expensive to compute once many libraries have been loaded,
-// so cache it here and do not reset.
-static const struct mach_header *get_dyld_hdr() {
-  static const struct mach_header *header = get_dyld_image_header();
-  return header;
-}
-
-void MemoryMappingLayout::GetSegmentAddrRange(uptr *start, uptr *end,
-                                              uptr vmaddr, uptr vmsize) {
-  if (current_image_ == kDyldImageIdx) {
-    // vmaddr is masked with 0xfffff because on macOS versions < 10.12,
-    // it contains an absolute address rather than an offset for dyld.
-    // To make matters even more complicated, this absolute address
-    // isn't actually the absolute segment address, but the offset portion
-    // of the address is accurate when combined with the dyld base address,
-    // and the mask will give just this offset.
-    if (start) *start = (vmaddr & 0xfffff) + (uptr)get_dyld_hdr();
-    if (end) *end = (vmaddr & 0xfffff) + vmsize + (uptr)get_dyld_hdr();
-  } else {
-    const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
-    if (start) *start = vmaddr + dlloff;
-    if (end) *end = vmaddr + vmsize + dlloff;
-  }
-}
-
 bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
                                char filename[], uptr filename_size,
                                uptr *protection, ModuleArch *arch, u8 *uuid) {
-  for (; current_image_ >= kDyldImageIdx; current_image_--) {
-    const struct mach_header *hdr =
-        (current_image_ == kDyldImageIdx)
-            ? get_dyld_hdr()
-            : _dyld_get_image_header(current_image_);
+  for (; current_image_ >= 0; current_image_--) {
+    const mach_header* hdr = _dyld_get_image_header(current_image_);
     if (!hdr) continue;
     if (current_load_cmd_count_ < 0) {
       // Set up for this image;