Merge pull request #6826 from apple/eng/r109116249-debugserver-flag-to-only-report-binary-image-load-addrs

Add a new report_load_commands option to jGetLoadedDynamicLibrariesInfos

Author: jasonmolenda

lldb/docs/lldb-gdb-remote.txt

@@ -1961,19 +1961,16 @@ for this region.
 //  This packet asks the remote debug stub to send the details about libraries
 //  being added/removed from the process as a performance optimization.
 //
-//  There are three ways this packet can be used.  All three return a dictionary of
+//  There are two ways this packet can be used.  Both return a dictionary of
 //  binary images formatted the same way.
 //
-//  On OS X 10.11, iOS 9, tvOS 9, watchOS 2 and earlier, the packet is used like
-//       jGetLoadedDynamicLibrariesInfos:{"image_count":1,"image_list_address":140734800075128}
-//  where the image_list_address is an array of {void* load_addr, void* mod_date, void* pathname}
-//  in the inferior process memory (and image_count is the number of elements in this array).
-//  lldb is using information from the dyld_all_image_infos structure to make these requests to
-//  debugserver.  This use is not supported on macOS 10.12, iOS 10, tvOS 10, watchOS 3 or newer.
-//
-//  On macOS 10.12, iOS 10, tvOS 10, watchOS 3 and newer, there are two calls.  One requests information
-//  on all shared libraries:
+//  One requests information on all shared libraries:
 //       jGetLoadedDynamicLibrariesInfos:{"fetch_all_solibs":true}
+//  with an optional `"report_load_commands":false` which can be added, asking
+//  that only the dyld SPI information (load addresses, filenames) be returned.
+//  The default behavior is that debugserver scans the mach-o header and load 
+//  commands of each binary, and returns it in the JSON reply.
+//
 //  And the second requests information about a list of shared libraries, given their load addresses:
 //       jGetLoadedDynamicLibrariesInfos:{"solib_addresses":[8382824135,3258302053,830202858503]}
 //

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

@@ -372,7 +372,6 @@ bool DynamicLoaderDarwin::JSONImageInformationIntoImageInfo(
     // clang-format off
     if (!image->HasKey("load_address") ||
         !image->HasKey("pathname") ||
-        !image->HasKey("mod_date") ||
         !image->HasKey("mach_header") ||
         image->GetValueForKey("mach_header")->GetAsDictionary() == nullptr ||
         !image->HasKey("segments") ||
@@ -383,8 +382,6 @@ bool DynamicLoaderDarwin::JSONImageInformationIntoImageInfo(
     // clang-format on
     image_infos[i].address =
         image->GetValueForKey("load_address")->GetAsInteger()->GetValue();
-    image_infos[i].mod_date =
-        image->GetValueForKey("mod_date")->GetAsInteger()->GetValue();
     image_infos[i].file_spec.SetFile(
         image->GetValueForKey("pathname")->GetAsString()->GetValue(),
         FileSpec::Style::native);
@@ -811,11 +808,11 @@ void DynamicLoaderDarwin::ImageInfo::PutToLog(Log *log) const {
   if (!log)
     return;
   if (address == LLDB_INVALID_ADDRESS) {
-    LLDB_LOG(log, "modtime={0:x+8} uuid={1} path='{2}' (UNLOADED)", mod_date,
-             uuid.GetAsString(), file_spec.GetPath());
+    LLDB_LOG(log, "uuid={1} path='{2}' (UNLOADED)", uuid.GetAsString(),
+             file_spec.GetPath());
   } else {
-    LLDB_LOG(log, "address={0:x+16} modtime={1:x+8} uuid={2} path='{3}'",
-             address, mod_date, uuid.GetAsString(), file_spec.GetPath());
+    LLDB_LOG(log, "address={0:x+16} uuid={2} path='{3}'", address,
+             uuid.GetAsString(), file_spec.GetPath());
     for (uint32_t i = 0; i < segments.size(); ++i)
       segments[i].PutToLog(log, slide);
   }

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h

@@ -100,8 +100,6 @@ class DynamicLoaderDarwin : public lldb_private::DynamicLoader {
     /// The amount to slide all segments by if there is a global
     /// slide.
     lldb::addr_t slide = 0;
-    /// Modification date for this dylib.
-    lldb::addr_t mod_date = 0;
     /// Resolved path for this dylib.
     lldb_private::FileSpec file_spec;
     /// UUID for this dylib if it has one, else all zeros.
@@ -128,7 +126,6 @@ class DynamicLoaderDarwin : public lldb_private::DynamicLoader {
       if (!load_cmd_data_only) {
         address = LLDB_INVALID_ADDRESS;
         slide = 0;
-        mod_date = 0;
         file_spec.Clear();
         ::memset(&header, 0, sizeof(header));
       }
@@ -142,8 +139,7 @@ class DynamicLoaderDarwin : public lldb_private::DynamicLoader {
 
     bool operator==(const ImageInfo &rhs) const {
       return address == rhs.address && slide == rhs.slide &&
-             mod_date == rhs.mod_date && file_spec == rhs.file_spec &&
-             uuid == rhs.uuid &&
+             file_spec == rhs.file_spec && uuid == rhs.uuid &&
              memcmp(&header, &rhs.header, sizeof(header)) == 0 &&
              segments == rhs.segments && os_type == rhs.os_type &&
              os_env == rhs.os_env;

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.cpp

@@ -693,7 +693,7 @@ bool DynamicLoaderMacOSXDYLD::ReadImageInfos(
          i++) {
       image_infos[i].address = info_data_ref.GetAddress(&info_data_offset);
       lldb::addr_t path_addr = info_data_ref.GetAddress(&info_data_offset);
-      image_infos[i].mod_date = info_data_ref.GetAddress(&info_data_offset);
+      info_data_ref.GetAddress(&info_data_offset); // mod_date, unused */
 
       char raw_path[PATH_MAX];
       m_process->ReadCStringFromMemory(path_addr, raw_path, sizeof(raw_path),

lldb/tools/debugserver/source/DNB.cpp

@@ -1023,20 +1023,11 @@ DNBGetTSDAddressForThread(nub_process_t pid, nub_thread_t tid,
   return INVALID_NUB_ADDRESS;
 }
 
-JSONGenerator::ObjectSP DNBGetLoadedDynamicLibrariesInfos(
-    nub_process_t pid, nub_addr_t image_list_address, nub_addr_t image_count) {
-  MachProcessSP procSP;
-  if (GetProcessSP(pid, procSP)) {
-    return procSP->GetLoadedDynamicLibrariesInfos(pid, image_list_address,
-                                                  image_count);
-  }
-  return JSONGenerator::ObjectSP();
-}
-
-JSONGenerator::ObjectSP DNBGetAllLoadedLibrariesInfos(nub_process_t pid) {
+JSONGenerator::ObjectSP
+DNBGetAllLoadedLibrariesInfos(nub_process_t pid, bool report_load_commands) {
   MachProcessSP procSP;
   if (GetProcessSP(pid, procSP)) {
-    return procSP->GetAllLoadedLibrariesInfos(pid);
+    return procSP->GetAllLoadedLibrariesInfos(pid, report_load_commands);
   }
   return JSONGenerator::ObjectSP();
 }

lldb/tools/debugserver/source/DNB.h

@@ -210,9 +210,8 @@ DNBGetTSDAddressForThread(nub_process_t pid, nub_thread_t tid,
                           uint64_t plo_pthread_tsd_base_address_offset,
                           uint64_t plo_pthread_tsd_base_offset,
                           uint64_t plo_pthread_tsd_entry_size);
-JSONGenerator::ObjectSP DNBGetLoadedDynamicLibrariesInfos(
-    nub_process_t pid, nub_addr_t image_list_address, nub_addr_t image_count);
-JSONGenerator::ObjectSP DNBGetAllLoadedLibrariesInfos(nub_process_t pid);
+JSONGenerator::ObjectSP
+DNBGetAllLoadedLibrariesInfos(nub_process_t pid, bool report_load_commands);
 JSONGenerator::ObjectSP
 DNBGetLibrariesInfoForAddresses(nub_process_t pid,
                                 std::vector<uint64_t> &macho_addresses);

lldb/tools/debugserver/source/MacOSX/MachProcess.h

@@ -72,12 +72,11 @@ class MachProcess {
   struct binary_image_information {
     std::string filename;
     uint64_t load_address;
-    uint64_t mod_date; // may not be available - 0 if so
     struct mach_o_information macho_info;
     bool is_valid_mach_header;
 
     binary_image_information()
-        : filename(), load_address(INVALID_NUB_ADDRESS), mod_date(0),
+        : filename(), load_address(INVALID_NUB_ADDRESS),
           is_valid_mach_header(false) {}
   };
 
@@ -259,7 +258,8 @@ class MachProcess {
                                      int wordsize,
                                      struct mach_o_information &inf);
   JSONGenerator::ObjectSP FormatDynamicLibrariesIntoJSON(
-      const std::vector<struct binary_image_information> &image_infos);
+      const std::vector<struct binary_image_information> &image_infos,
+      bool report_load_commands);
   uint32_t GetPlatform();
   /// Get the runtime platform from DYLD via SPI.
   uint32_t GetProcessPlatformViaDYLDSPI();
@@ -271,12 +271,12 @@ class MachProcess {
   /// command details.
   void GetAllLoadedBinariesViaDYLDSPI(
       std::vector<struct binary_image_information> &image_infos);
-  JSONGenerator::ObjectSP GetLoadedDynamicLibrariesInfos(
-      nub_process_t pid, nub_addr_t image_list_address, nub_addr_t image_count);
   JSONGenerator::ObjectSP
   GetLibrariesInfoForAddresses(nub_process_t pid,
                                std::vector<uint64_t> &macho_addresses);
-  JSONGenerator::ObjectSP GetAllLoadedLibrariesInfos(nub_process_t pid);
+  JSONGenerator::ObjectSP
+  GetAllLoadedLibrariesInfos(nub_process_t pid,
+                             bool fetch_report_load_commands);
   JSONGenerator::ObjectSP GetSharedCacheInfo(nub_process_t pid);
 
   nub_size_t GetNumThreads() const;

lldb/tools/debugserver/source/MacOSX/MachProcess.mm

@@ -912,22 +912,34 @@ static bool mach_header_validity_test(uint32_t magic, uint32_t cputype) {
 // create a JSONGenerator object
 // with all the details we want to send to lldb.
 JSONGenerator::ObjectSP MachProcess::FormatDynamicLibrariesIntoJSON(
-    const std::vector<struct binary_image_information> &image_infos) {
+    const std::vector<struct binary_image_information> &image_infos,
+    bool report_load_commands) {
 
   JSONGenerator::ArraySP image_infos_array_sp(new JSONGenerator::Array());
 
   const size_t image_count = image_infos.size();
 
   for (size_t i = 0; i < image_count; i++) {
-    if (!image_infos[i].is_valid_mach_header)
+    // If we should report the Mach-O header and load commands,
+    // and those were unreadable, don't report anything about this
+    // binary.
+    if (report_load_commands && !image_infos[i].is_valid_mach_header)
       continue;
     JSONGenerator::DictionarySP image_info_dict_sp(
         new JSONGenerator::Dictionary());
     image_info_dict_sp->AddIntegerItem("load_address",
                                        image_infos[i].load_address);
-    image_info_dict_sp->AddIntegerItem("mod_date", image_infos[i].mod_date);
+    // TODO: lldb currently rejects a response without this, but it
+    // is always zero from dyld.  It can be removed once we've had time
+    // for lldb's that require it to be present are obsolete.
+    image_info_dict_sp->AddIntegerItem("mod_date", 0);
     image_info_dict_sp->AddStringItem("pathname", image_infos[i].filename);
 
+    if (!report_load_commands) {
+      image_infos_array_sp->AddItem(image_info_dict_sp);
+      continue;
+    }
+
     uuid_string_t uuidstr;
     uuid_unparse_upper(image_infos[i].macho_info.uuid, uuidstr);
     image_info_dict_sp->AddStringItem("uuid", uuidstr);
@@ -1000,109 +1012,6 @@ static bool mach_header_validity_test(uint32_t magic, uint32_t cputype) {
   return reply_sp;
 }
 
-// Get the shared library information using the old (pre-macOS 10.12, pre-iOS
-// 10, pre-tvOS 10, pre-watchOS 3)
-// code path.  We'll be given the address of an array of structures in the form
-// {void* load_addr, void* mod_date, void* pathname}
-//
-// In macOS 10.12 etc and newer, we'll use SPI calls into dyld to gather this
-// information.
-JSONGenerator::ObjectSP MachProcess::GetLoadedDynamicLibrariesInfos(
-    nub_process_t pid, nub_addr_t image_list_address, nub_addr_t image_count) {
-
-  JSONGenerator::ObjectSP empty_reply_sp(new JSONGenerator::Dictionary());
-  int pointer_size = GetInferiorAddrSize(pid);
-
-  std::vector<struct binary_image_information> image_infos;
-  size_t image_infos_size = image_count * 3 * pointer_size;
-
-  uint8_t *image_info_buf = (uint8_t *)malloc(image_infos_size);
-  if (image_info_buf == NULL) {
-    return empty_reply_sp;
-  }
-  if (ReadMemory(image_list_address, image_infos_size, image_info_buf) !=
-      image_infos_size) {
-    return empty_reply_sp;
-  }
-
-  /// First the image_infos array with (load addr, pathname, mod date)
-  /// tuples
-
-  for (size_t i = 0; i < image_count; i++) {
-    struct binary_image_information info;
-    nub_addr_t pathname_address;
-    if (pointer_size == 4) {
-      uint32_t load_address_32;
-      uint32_t pathname_address_32;
-      uint32_t mod_date_32;
-      ::memcpy(&load_address_32, image_info_buf + (i * 3 * pointer_size), 4);
-      ::memcpy(&pathname_address_32,
-               image_info_buf + (i * 3 * pointer_size) + pointer_size, 4);
-      ::memcpy(&mod_date_32,
-               image_info_buf + (i * 3 * pointer_size) + pointer_size +
-                   pointer_size,
-               4);
-      info.load_address = load_address_32;
-      info.mod_date = mod_date_32;
-      pathname_address = pathname_address_32;
-    } else {
-      uint64_t load_address_64;
-      uint64_t pathname_address_64;
-      uint64_t mod_date_64;
-      ::memcpy(&load_address_64, image_info_buf + (i * 3 * pointer_size), 8);
-      ::memcpy(&pathname_address_64,
-               image_info_buf + (i * 3 * pointer_size) + pointer_size, 8);
-      ::memcpy(&mod_date_64,
-               image_info_buf + (i * 3 * pointer_size) + pointer_size +
-                   pointer_size,
-               8);
-      info.load_address = load_address_64;
-      info.mod_date = mod_date_64;
-      pathname_address = pathname_address_64;
-    }
-    char strbuf[17];
-    info.filename = "";
-    uint64_t pathname_ptr = pathname_address;
-    bool still_reading = true;
-    while (still_reading && ReadMemory(pathname_ptr, sizeof(strbuf) - 1,
-                                       strbuf) == sizeof(strbuf) - 1) {
-      strbuf[sizeof(strbuf) - 1] = '\0';
-      info.filename += strbuf;
-      pathname_ptr += sizeof(strbuf) - 1;
-      // Stop if we found nul byte indicating the end of the string
-      for (size_t i = 0; i < sizeof(strbuf) - 1; i++) {
-        if (strbuf[i] == '\0') {
-          still_reading = false;
-          break;
-        }
-      }
-    }
-    uuid_clear(info.macho_info.uuid);
-    image_infos.push_back(info);
-  }
-  if (image_infos.size() == 0) {
-    return empty_reply_sp;
-  }
-
-  free(image_info_buf);
-
-  ///  Second, read the mach header / load commands for all the dylibs
-
-  for (size_t i = 0; i < image_count; i++) {
-    // The SPI to provide platform is not available on older systems.
-    uint32_t platform = 0;
-    if (GetMachOInformationFromMemory(platform, image_infos[i].load_address,
-                                      pointer_size,
-                                      image_infos[i].macho_info)) {
-      image_infos[i].is_valid_mach_header = true;
-    }
-  }
-
-  ///  Third, format all of the above in the JSONGenerator object.
-
-  return FormatDynamicLibrariesIntoJSON(image_infos);
-}
-
 /// From dyld SPI header dyld_process_info.h
 typedef void *dyld_process_info;
 struct dyld_process_cache_info {
@@ -1162,21 +1071,24 @@ static bool mach_header_validity_test(uint32_t magic, uint32_t cputype) {
 // in
 // macOS 10.12, iOS 10, tvOS 10, watchOS 3 and newer.
 JSONGenerator::ObjectSP
-MachProcess::GetAllLoadedLibrariesInfos(nub_process_t pid) {
+MachProcess::GetAllLoadedLibrariesInfos(nub_process_t pid,
+                                        bool report_load_commands) {
 
   int pointer_size = GetInferiorAddrSize(pid);
   std::vector<struct binary_image_information> image_infos;
   GetAllLoadedBinariesViaDYLDSPI(image_infos);
-  uint32_t platform = GetPlatform();
-  const size_t image_count = image_infos.size();
-  for (size_t i = 0; i < image_count; i++) {
-    if (GetMachOInformationFromMemory(platform, image_infos[i].load_address,
-                                      pointer_size,
-                                      image_infos[i].macho_info)) {
-      image_infos[i].is_valid_mach_header = true;
+  if (report_load_commands) {
+    uint32_t platform = GetPlatform();
+    const size_t image_count = image_infos.size();
+    for (size_t i = 0; i < image_count; i++) {
+      if (GetMachOInformationFromMemory(platform, image_infos[i].load_address,
+                                        pointer_size,
+                                        image_infos[i].macho_info)) {
+        image_infos[i].is_valid_mach_header = true;
+      }
     }
   }
-    return FormatDynamicLibrariesIntoJSON(image_infos);
+  return FormatDynamicLibrariesIntoJSON(image_infos, report_load_commands);
 }
 
 // Fetch information about the shared libraries at the given load addresses
@@ -1226,7 +1138,8 @@ static bool mach_header_validity_test(uint32_t magic, uint32_t cputype) {
         image_infos[i].is_valid_mach_header = true;
       }
     }
-    return FormatDynamicLibrariesIntoJSON(image_infos);
+    return FormatDynamicLibrariesIntoJSON(image_infos,
+                                          /* report_load_commands =  */ true);
 }
 
 // From dyld's internal podyld_process_info.h: