Export GVISOR_PLATFORM_SUPPORT environment variable for tests.

This environment variable encodes what capabilities the platform
supports, and is consumed by `platform_util.cc` to determine
which syscall tests are appropriate to run.

PiperOrigin-RevId: 452870567

test/runner/BUILD

@@ -27,4 +27,5 @@ bzl_library(
     name = "defs_bzl",
     srcs = ["defs.bzl"],
     visibility = ["//visibility:private"],
+    deps = ["//tools:defs_bzl"],
 )

test/runner/defs.bzl

@@ -1,6 +1,15 @@
 """Defines a rule for syscall test targets."""
 
-load("//tools:defs.bzl", "default_platform", "platforms")
+load("//tools:defs.bzl", "default_platform", "platform_capabilities", "platforms")
+
+# Maps platform names to a GVISOR_PLATFORM_SUPPORT environment variable consumed by platform_util.cc
+_platform_support_env_vars = {
+    platform: ",".join(sorted([
+        ("%s:%s" % (capability, "TRUE" if supported else "FALSE"))
+        for capability, supported in support.items()
+    ]))
+    for platform, support in platform_capabilities.items()
+}
 
 def _runner_test_impl(ctx):
     # Generate a runner binary.
@@ -105,9 +114,19 @@ def _syscall_test(
 
     container = "container" in tags
 
+    if platform == "native":
+        # The "native" platform supports everything.
+        platform_support = ",".join(sorted([
+            ("%s:TRUE" % key)
+            for key in platform_capabilities[default_platform].keys()
+        ]))
+    else:
+        platform_support = _platform_support_env_vars.get(platform, "")
+
     runner_args = [
         # Arguments are passed directly to runner binary.
         "--platform=" + platform,
+        "--platform-support=" + platform_support,
         "--network=" + network,
         "--use-tmpfs=" + str(use_tmpfs),
         "--file-access=" + file_access,

test/runner/main.go

@@ -43,6 +43,7 @@ var (
 	debug              = flag.Bool("debug", false, "enable debug logs")
 	strace             = flag.Bool("strace", false, "enable strace logs")
 	platform           = flag.String("platform", "ptrace", "platform to run on")
+	platformSupport    = flag.String("platform-support", "", "String passed to the test as GVISOR_PLATFORM_SUPPORT environment variable. Used to determine which syscall tests are expected to work with the current platform.")
 	network            = flag.String("network", "none", "network stack to run on (sandbox, host, none)")
 	useTmpfs           = flag.Bool("use-tmpfs", false, "mounts tmpfs for /tmp")
 	fileAccess         = flag.String("file-access", "exclusive", "mounts root in exclusive or shared mode")
@@ -58,6 +59,11 @@ var (
 	leakCheck = flag.Bool("leak-check", false, "check for reference leaks")
 )
 
+const (
+	// Environment variable used by platform_util.cc to determine platform capabilities.
+	platformSupportEnvVar = "GVISOR_PLATFORM_SUPPORT"
+)
+
 // runTestCaseNative runs the test case directly on the host machine.
 func runTestCaseNative(testBin string, tc gtest.TestCase, t *testing.T) {
 	// These tests might be running in parallel, so make sure they have a
@@ -100,6 +106,10 @@ func runTestCaseNative(testBin string, tc gtest.TestCase, t *testing.T) {
 		env = append(env, "TEST_UDS_ATTACH_TREE="+socketDir)
 	}
 
+	if *platformSupport != "" {
+		env = append(env, fmt.Sprintf("%s=%s", platformSupportEnvVar, *platformSupport))
+	}
+
 	cmd := exec.Command(testBin, tc.Args()...)
 	cmd.Env = env
 	cmd.Stdout = os.Stdout
@@ -399,6 +409,9 @@ func runTestCaseRunsc(testBin string, tc gtest.TestCase, t *testing.T) {
 		lisafsVar   = "LISAFS_ENABLED"
 	)
 	env := append(os.Environ(), platformVar+"="+*platform, networkVar+"="+*network)
+	if *platformSupport != "" {
+		env = append(env, fmt.Sprintf("%s=%s", platformSupportEnvVar, *platformSupport))
+	}
 	if *fuse {
 		env = append(env, fuseVar+"=TRUE")
 	} else {

test/util/platform_util.cc

@@ -14,34 +14,87 @@
 
 #include "test/util/platform_util.h"
 
+#include <vector>
+
 #include "test/util/test_util.h"
 
 namespace gvisor {
 namespace testing {
 
 PlatformSupport PlatformSupport32Bit() {
-  if (GvisorPlatform() == Platform::kPtrace ||
-      GvisorPlatform() == Platform::kKVM) {
-    return PlatformSupport::NotSupported;
-  } else {
-    return PlatformSupport::Allowed;
+  const char* support = std::getenv("GVISOR_PLATFORM_SUPPORT");
+  if (support != nullptr) {
+    if (std::string(support).find("32BIT:TRUE") != std::string::npos) {
+      return PlatformSupport::Allowed;
+    }
+    if (std::string(support).find("32BIT:FALSE") != std::string::npos) {
+      return PlatformSupport::NotSupported;
+    }
+    std::cerr << "GVISOR_PLATFORM_SUPPORT variable does not contain 32BIT "
+                 "support information: "
+              << support << std::endl;
+    TEST_CHECK(false);
   }
+  std::cerr << "GVISOR_PLATFORM_SUPPORT variable undefined" << std::endl;
+  TEST_CHECK(false);
 }
 
 PlatformSupport PlatformSupportAlignmentCheck() {
-  return PlatformSupport::Allowed;
+  const char* support = std::getenv("GVISOR_PLATFORM_SUPPORT");
+  if (support != nullptr) {
+    if (std::string(support).find("ALIGNMENT_CHECK:TRUE") !=
+        std::string::npos) {
+      return PlatformSupport::Allowed;
+    }
+    if (std::string(support).find("ALIGNMENT_CHECK:FALSE") !=
+        std::string::npos) {
+      return PlatformSupport::NotSupported;
+    }
+    std::cerr
+        << "GVISOR_PLATFORM_SUPPORT variable does not contain ALIGNMENT_CHECK "
+           "support information: "
+        << support << std::endl;
+    TEST_CHECK(false);
+  }
+  std::cerr << "GVISOR_PLATFORM_SUPPORT variable undefined" << std::endl;
+  TEST_CHECK(false);
 }
 
 PlatformSupport PlatformSupportMultiProcess() {
-  return PlatformSupport::Allowed;
+  const char* support = std::getenv("GVISOR_PLATFORM_SUPPORT");
+  if (support != nullptr) {
+    if (std::string(support).find("MULTIPROCESS:TRUE") != std::string::npos) {
+      return PlatformSupport::Allowed;
+    }
+    if (std::string(support).find("MULTIPROCESS:FALSE") != std::string::npos) {
+      return PlatformSupport::NotSupported;
+    }
+    std::cerr
+        << "GVISOR_PLATFORM_SUPPORT variable does not contain MULTIPROCESS "
+           "support information: "
+        << support << std::endl;
+    TEST_CHECK(false);
+  }
+  std::cerr << "GVISOR_PLATFORM_SUPPORT variable undefined" << std::endl;
+  TEST_CHECK(false);
 }
 
 PlatformSupport PlatformSupportInt3() {
-  if (GvisorPlatform() == Platform::kKVM) {
-    return PlatformSupport::NotSupported;
-  } else {
-    return PlatformSupport::Allowed;
+  const char* support = std::getenv("GVISOR_PLATFORM_SUPPORT");
+  if (support != nullptr) {
+    if (std::string(support).find("INT3:TRUE") != std::string::npos) {
+      return PlatformSupport::Allowed;
+    }
+    if (std::string(support).find("INT3:FALSE") != std::string::npos) {
+      return PlatformSupport::NotSupported;
+    }
+    std::cerr << "GVISOR_PLATFORM_SUPPORT variable does not contain INT3 "
+                 "support information: "
+              << support << std::endl;
+    TEST_CHECK(false);
   }
+  std::cerr << "GVISOR_PLATFORM_SUPPORT variable undefined" << std::endl;
+  TEST_CHECK(false);
 }
 
 }  // namespace testing

tools/bazeldefs/platforms.bzl

@@ -6,4 +6,28 @@ platforms = {
     "kvm": [],
 }
 
+# Capabilities that platforms may or may not support.
+# Used by platform_util.cc to determine which syscall tests are appropriate.
+_CAPABILITY_32BIT = "32BIT"
+_CAPABILITY_ALIGNMENT_CHECK = "ALIGNMENT_CHECK"
+_CAPABILITY_MULTIPROCESS = "MULTIPROCESS"
+_CAPABILITY_INT3 = "INT3"
+
+# platform_capabilities maps platform names to a dictionary of capabilities mapped to
+# True (supported) or False (unsupported).
+platform_capabilities = {
+    "ptrace": {
+        _CAPABILITY_32BIT: False,
+        _CAPABILITY_ALIGNMENT_CHECK: True,
+        _CAPABILITY_MULTIPROCESS: True,
+        _CAPABILITY_INT3: True,
+    },
+    "kvm": {
+        _CAPABILITY_32BIT: False,
+        _CAPABILITY_ALIGNMENT_CHECK: True,
+        _CAPABILITY_MULTIPROCESS: True,
+        _CAPABILITY_INT3: False,
+    },
+}
+
 default_platform = "ptrace"

tools/defs.bzl

@@ -12,7 +12,7 @@ load("//tools/bazeldefs:defs.bzl", _BuildSettingInfo = "BuildSettingInfo", _amd6
 load("//tools/bazeldefs:cc.bzl", _cc_binary = "cc_binary", _cc_flags_supplier = "cc_flags_supplier", _cc_grpc_library = "cc_grpc_library", _cc_library = "cc_library", _cc_proto_library = "cc_proto_library", _cc_test = "cc_test", _cc_toolchain = "cc_toolchain", _gbenchmark = "gbenchmark", _gbenchmark_internal = "gbenchmark_internal", _grpcpp = "grpcpp", _gtest = "gtest", _vdso_linker_option = "vdso_linker_option")
 load("//tools/bazeldefs:go.bzl", _gazelle = "gazelle", _go_binary = "go_binary", _go_embed_data = "go_embed_data", _go_grpc_and_proto_libraries = "go_grpc_and_proto_libraries", _go_library = "go_library", _go_path = "go_path", _go_proto_library = "go_proto_library", _go_rule = "go_rule", _go_test = "go_test", _gotsan_flag_values = "gotsan_flag_values", _gotsan_values = "gotsan_values", _select_goarch = "select_goarch", _select_goos = "select_goos")
 load("//tools/bazeldefs:pkg.bzl", _pkg_deb = "pkg_deb", _pkg_tar = "pkg_tar")
-load("//tools/bazeldefs:platforms.bzl", _default_platform = "default_platform", _platforms = "platforms")
+load("//tools/bazeldefs:platforms.bzl", _default_platform = "default_platform", _platform_capabilities = "platform_capabilities", _platforms = "platforms")
 load("//tools/bazeldefs:tags.bzl", "go_suffixes")
 
 # Core rules.
@@ -59,6 +59,7 @@ pkg_tar = _pkg_tar
 # Platform options.
 default_platform = _default_platform
 platforms = _platforms
+platform_capabilities = _platform_capabilities
 
 def _go_add_tags(ctx):
     """ Adds tags to the given source file. """