Ensure we can build with older SDKs

Ensure we can keep building debugserver with
`memory tag read <addr-expr>` support with older
SDKs.

Author: yln

lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp

@@ -13,6 +13,7 @@
 #include "MachVMMemory.h"
 #include "DNBLog.h"
 #include "MachVMRegion.h"
+#include <cassert>
 #include <dlfcn.h>
 #include <mach/mach_vm.h>
 #include <mach/shared_region.h>
@@ -157,12 +158,23 @@ nub_bool_t MachVMMemory::GetMemoryRegionInfo(task_t task, nub_addr_t address,
 #ifndef VM_OFFSET_LIST_MAX
 #define VM_OFFSET_LIST_MAX 512
 #endif
+using mach_vm_offset_list_t = mach_vm_offset_t *;
+using mach_vm_update_pointers_with_remote_tags_t = kern_return_t(
+    mach_port_name_t target, mach_vm_offset_list_t in_pointer_list,
+    mach_msg_type_number_t in_pointer_listCnt,
+    mach_vm_offset_list_t out_pointer_list,
+    mach_msg_type_number_t *out_pointer_listCnt);
+
 nub_bool_t MachVMMemory::GetMemoryTags(task_t task, nub_addr_t address,
                                        nub_size_t size,
                                        std::vector<uint8_t> &tags) {
+  static auto mach_vm_update_pointers_with_remote_tags =
+      (mach_vm_update_pointers_with_remote_tags_t *)dlsym(
+          RTLD_DEFAULT, "mach_vm_update_pointers_with_remote_tags");
+  assert(mach_vm_update_pointers_with_remote_tags);
+
   // Max batch size supported by mach_vm_update_pointers_with_remote_tags()
   constexpr uint32_t max_ptr_count = VM_OFFSET_LIST_MAX;
-
   constexpr uint32_t tag_shift = 56;
   constexpr nub_addr_t tag_mask =
       ((nub_addr_t)0x0f << tag_shift); // Lower half of top byte
@@ -177,7 +189,7 @@ nub_bool_t MachVMMemory::GetMemoryTags(task_t task, nub_addr_t address,
     ptr_arr[i] = (address + i * tag_granule);
 
   mach_msg_type_number_t ptr_count_out = ptr_count;
-  m_err = ::mach_vm_update_pointers_with_remote_tags(
+  m_err = mach_vm_update_pointers_with_remote_tags(
       task, ptr_arr.get(), ptr_count, ptr_arr.get(), &ptr_count_out);
 
   const bool failed = (m_err.Fail() || (ptr_count != ptr_count_out));

lldb/tools/debugserver/source/MacOSX/MachVMRegion.cpp

@@ -114,6 +114,11 @@ bool MachVMRegion::RestoreProtections() {
   return false;
 }
 
+#ifdef VM_REGION_FLAG_JIT_ENABLED
+#define VM_REGION_HAS_FLAGS 1
+#else
+#define VM_REGION_HAS_FLAGS 0
+#endif
 bool MachVMRegion::GetRegionForAddress(nub_addr_t addr) {
   // Restore any original protections and clear our vars
   Clear();
@@ -140,6 +145,7 @@ bool MachVMRegion::GetRegionForAddress(nub_addr_t addr) {
   if (failed)
     return false;
   if (log_protections) {
+#if VM_REGION_HAS_FLAGS
     DNBLogThreaded("info = { prot = %u, "
                    "max_prot = %u, "
                    "inheritance = 0x%8.8x, "
@@ -159,6 +165,29 @@ bool MachVMRegion::GetRegionForAddress(nub_addr_t addr) {
                    m_data.shadow_depth, m_data.external_pager,
                    m_data.share_mode, m_data.is_submap, m_data.behavior,
                    m_data.object_id, m_data.user_wired_count, m_data.flags);
+#else
+    // Duplicate log call instead of #if-defing printing of flags to avoid
+    // compiler warning: 'embedding a directive within macro arguments has
+    // undefined behavior'
+    DNBLogThreaded("info = { prot = %u, "
+                   "max_prot = %u, "
+                   "inheritance = 0x%8.8x, "
+                   "offset = 0x%8.8llx, "
+                   "user_tag = 0x%8.8x, "
+                   "ref_count = %u, "
+                   "shadow_depth = %u, "
+                   "ext_pager = %u, "
+                   "share_mode = %u, "
+                   "is_submap = %d, "
+                   "behavior = %d, "
+                   "object_id = 0x%8.8x, "
+                   "user_wired_count = 0x%4.4x }",
+                   m_data.protection, m_data.max_protection, m_data.inheritance,
+                   (uint64_t)m_data.offset, m_data.user_tag, m_data.ref_count,
+                   m_data.shadow_depth, m_data.external_pager,
+                   m_data.share_mode, m_data.is_submap, m_data.behavior,
+                   m_data.object_id, m_data.user_wired_count);
+#endif
   }
   m_curr_protection = m_data.protection;
 
@@ -189,12 +218,14 @@ uint32_t MachVMRegion::GetDNBPermissions() const {
 #endif
 std::vector<std::string> MachVMRegion::GetFlags() const {
   std::vector<std::string> flags;
+#if VM_REGION_HAS_FLAGS
   if (m_data.flags & VM_REGION_FLAG_JIT_ENABLED)
     flags.push_back("jit");
   if (m_data.flags & VM_REGION_FLAG_TPRO_ENABLED)
     flags.push_back("tpro");
   if (m_data.flags & VM_REGION_FLAG_MTE_ENABLED)
     flags.push_back("mt");
+#endif
   return flags;
 }
 

lldb/tools/debugserver/source/RNBRemote.cpp

@@ -22,7 +22,7 @@
 #include <mach/mach_vm.h>
 #include <mach/task_info.h>
 #include <memory>
-#if __has_include(<os/security_config.h>) // macOS 26.1
+#if __has_include(<os/security_config.h>)
 #include <os/security_config.h>
 #endif
 #include <pwd.h>
@@ -6247,18 +6247,8 @@ GetCPUTypesFromHost(nub_process_t pid) {
   return {cputype, cpusubtype};
 }
 
-#if !__has_include(<os/security_config.h>) // macOS 26.1
-extern "C" {
-using os_security_config_t = uint64_t;
-#define OS_SECURITY_CONFIG_MTE 0x4
-
-API_AVAILABLE(macos(26.0), ios(26.0), tvos(26.0), watchos(26.0), visionos(26.0),
-              driverkit(25.0))
-OS_EXPORT OS_NOTHROW OS_NONNULL_ALL int
-os_security_config_get_for_proc(pid_t pid, os_security_config_t *config);
-}
-#endif
 static bool ProcessRunningWithMemoryTagging(pid_t pid) {
+#if __has_include(<os/security_config.h>)
   if (__builtin_available(macOS 26.0, iOS 26.0, tvOS 26.0, watchOS 26.0,
                           visionOS 26.0, driverkit 25.0, *)) {
     os_security_config_t config;
@@ -6268,6 +6258,7 @@ static bool ProcessRunningWithMemoryTagging(pid_t pid) {
 
     return (config & OS_SECURITY_CONFIG_MTE);
   }
+#endif
   return false;
 }