From bd5ccf95d11dec6c4bbf52e1996a364ec9c785bc Mon Sep 17 00:00:00 2001
From: Nourhan Hasan <nourhan.m.hasan@gmail.com>
Date: Thu, 11 Jun 2026 11:30:22 -0700
Subject: [PATCH] [vm/service]: Add OS::SafeReadMemory for macOS using
 mach_vm_read_overwrite

TEST=runtime/vm/service_test.cc

Cq-Include-Trybots: dart/try:vm-asan-mac-release-arm64-try,vm-dyn-mac-debug-arm64-try,vm-mac-debug-arm64-try,vm-mac-debug-x64-try,vm-tsan-mac-release-arm64-try,vm-ubsan-mac-release-arm64-try
Change-Id: I1be990f3debb7e0b7102f54e8c5bec25252756d4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/507040
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
---
 runtime/tests/vm/vm.status |  4 ----
 runtime/vm/os_macos.cc     | 46 +++++++++++++++++++++++++++++---------
 runtime/vm/service.cc      |  3 ++-
 runtime/vm/service_test.cc |  2 ++
 4 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/runtime/tests/vm/vm.status b/runtime/tests/vm/vm.status
index 37bc155ab8b..cad5b4c37de 100644
--- a/runtime/tests/vm/vm.status
+++ b/runtime/tests/vm/vm.status
@@ -232,10 +232,6 @@ dart/data_uri_spawn_test: Skip # TODO(zra): package:unittest is not in the image
 dart/spawn_shutdown_test: Skip # OOM crash can bring down the OS.
 
 [ $system == macos ]
-cc/Service_ReadNativeMemory_InvalidAddress: Skip
-cc/Service_ReadNativeMemory_LargeRead: Skip
-cc/Service_ReadNativeMemory_NullAddress: Skip
-cc/Service_ReadNativeMemory_ValidAddress: Skip
 dart/transferable_throws_oom_test: SkipByDesign # Allocating too much memory to cause OOM doesn't work on mac
 
 [ $system == windows ]
diff --git a/runtime/vm/os_macos.cc b/runtime/vm/os_macos.cc
index c5c45871429..727717b62df 100644
--- a/runtime/vm/os_macos.cc
+++ b/runtime/vm/os_macos.cc
@@ -7,18 +7,21 @@
 
 #include "vm/os.h"
 
-#include <dlfcn.h>           // NOLINT
-#include <errno.h>           // NOLINT
-#include <limits.h>          // NOLINT
-#include <mach-o/loader.h>   // NOLINT
-#include <mach/clock.h>      // NOLINT
-#include <mach/mach.h>       // NOLINT
-#include <mach/mach_time.h>  // NOLINT
-#include <sys/resource.h>    // NOLINT
-#include <sys/time.h>        // NOLINT
-#include <unistd.h>          // NOLINT
+#include <dlfcn.h>            // NOLINT
+#include <errno.h>            // NOLINT
+#include <limits.h>           // NOLINT
+#include <mach-o/loader.h>    // NOLINT
+#include <mach/clock.h>       // NOLINT
+#include <mach/mach.h>        // NOLINT
+#include <mach/mach_error.h>  // NOLINT
+#include <mach/mach_time.h>   // NOLINT
+#include <sys/resource.h>     // NOLINT
+#include <sys/time.h>         // NOLINT
+#include <unistd.h>           // NOLINT
 #if DART_HOST_OS_IOS
 #include <syslog.h>  // NOLINT
+#else
+#include <mach/mach_vm.h>  // NOLINT
 #endif
 
 #include "platform/utils.h"
@@ -131,6 +134,29 @@ uintptr_t OS::CurrentRSS() {
   return info.resident_size;
 }
 
+bool OS::SafeReadMemory(void* address,
+                        uint8_t* buffer,
+                        size_t size_in_bytes,
+                        const char** error) {
+#if DART_HOST_OS_IOS
+  vm_size_t bytes_read = 0;
+  kern_return_t kr = vm_read_overwrite(
+      mach_task_self(), reinterpret_cast<vm_address_t>(address), size_in_bytes,
+      reinterpret_cast<vm_address_t>(buffer), &bytes_read);
+#else
+  mach_vm_size_t bytes_read = 0;
+  kern_return_t kr = mach_vm_read_overwrite(
+      mach_task_self(), reinterpret_cast<mach_vm_address_t>(address),
+      size_in_bytes, reinterpret_cast<mach_vm_address_t>(buffer), &bytes_read);
+#endif
+
+  if (kr != KERN_SUCCESS || bytes_read != size_in_bytes) {
+    *error = OS::SCreate(nullptr, "%s (kr=%d)", mach_error_string(kr), kr);
+    return false;
+  }
+  return true;
+}
+
 void OS::Sleep(int64_t millis) {
   int64_t micros = millis * kMicrosecondsPerMillisecond;
   SleepMicros(micros);
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index bb4dc5ff0ef..7d1ecdc90fb 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -6268,7 +6268,8 @@ static void ReadNativeMemoryHelper(JSONStream* js,
   bool ok = OS::SafeReadMemory(reinterpret_cast<void*>(address), buffer.get(),
                                size, &read_error);
 #elif defined(DART_HOST_OS_MACOS) || defined(DART_HOST_OS_IOS)
-  bool ok = false;  // TODO(thenourhan): implement using mach_vm_read
+  bool ok = OS::SafeReadMemory(reinterpret_cast<void*>(address), buffer.get(),
+                               size, &read_error);
 #elif defined(DART_HOST_OS_WINDOWS)
   bool ok = OS::SafeReadMemory(reinterpret_cast<void*>(address), buffer.get(),
                                size, &read_error);
diff --git a/runtime/vm/service_test.cc b/runtime/vm/service_test.cc
index a454ae2bdf4..18a21b4b5c2 100644
--- a/runtime/vm/service_test.cc
+++ b/runtime/vm/service_test.cc
@@ -824,6 +824,8 @@ ISOLATE_UNIT_TEST_CASE(Service_ReadNativeMemory_InvalidAddress) {
   EXPECT_SUBSTRING("Input\\/output error", handler.msg());
 #elif defined(DART_HOST_OS_WINDOWS)
   EXPECT_SUBSTRING("error 299", handler.msg());
+#elif defined(DART_HOST_OS_MACOS)
+  EXPECT_SUBSTRING("invalid address", handler.msg());
 #endif
 }