Test stack unwinding more thoroughly

Check unwinding recursive calls.
Verify we can unwind in absence of unwind tables.

PiperOrigin-RevId: 513506498
Change-Id: Ib87240b7481dae3a4513c944e17a7924a54926e9

sandboxed_api/sandbox2/stack_trace_test.cc

@@ -54,9 +54,11 @@ using ::testing::IsEmpty;
 using ::testing::StartsWith;
 
 struct TestCase {
-  std::string arg = "1";
+  std::string testname = "CrashMe";
+  int testno = 1;
+  int testmode = 1;
   int final_status = Result::SIGNALED;
-  std::string function_name = "CrashMe";
+  std::string function_name = testname;
   std::string full_function_description = "CrashMe(char)";
   std::function<void(PolicyBuilder*)> modify_policy;
   absl::Duration wall_time_limit = absl::ZeroDuration();
@@ -67,7 +69,8 @@ class StackTraceTest : public ::testing::TestWithParam<TestCase> {};
 // Test that symbolization of stack traces works.
 void SymbolizationWorksCommon(TestCase param) {
   const std::string path = GetTestSourcePath("sandbox2/testcases/symbolize");
-  std::vector<std::string> args = {path, param.arg};
+  std::vector<std::string> args = {path, absl::StrCat(param.testno),
+                                   absl::StrCat(param.testmode)};
 
   auto policybuilder = PolicyBuilder()
                            // Don't restrict the syscalls at all.
@@ -87,6 +90,20 @@ void SymbolizationWorksCommon(TestCase param) {
   // Check that demangling works as well.
   EXPECT_THAT(result.stack_trace(),
               Contains(StartsWith(param.full_function_description)));
+  EXPECT_THAT(result.stack_trace(), Contains(StartsWith("RunTest")));
+  EXPECT_THAT(result.stack_trace(), Contains(StartsWith("main")));
+  if (param.testmode == 2) {
+    EXPECT_THAT(result.stack_trace(),
+                Contains(StartsWith("RecurseA")).Times(5));
+    EXPECT_THAT(result.stack_trace(),
+                Contains(StartsWith("RecurseB")).Times(5));
+  } else if (param.testmode == 3) {
+    EXPECT_THAT(result.stack_trace(), Contains(StartsWith("LibRecurse")));
+    EXPECT_THAT(result.stack_trace(),
+                Contains(StartsWith("LibRecurseA")).Times(5));
+    EXPECT_THAT(result.stack_trace(),
+                Contains(StartsWith("LibRecurseB")).Times(5));
+  }
 }
 
 void SymbolizationWorksWithModifiedPolicy(
@@ -206,21 +223,21 @@ INSTANTIATE_TEST_SUITE_P(
     Instantiation, StackTraceTest,
     ::testing::Values(
         TestCase{
-            .arg = "1",
+            .testname = "CrashMe",
+            .testno = 1,
             .final_status = Result::SIGNALED,
-            .function_name = "CrashMe",
             .full_function_description = "CrashMe(char)",
         },
         TestCase{
-            .arg = "2",
+            .testname = "ViolatePolicy",
+            .testno = 2,
             .final_status = Result::VIOLATION,
-            .function_name = "ViolatePolicy",
             .full_function_description = "ViolatePolicy(int)",
         },
         TestCase{
-            .arg = "3",
+            .testname = "ExitNormally",
+            .testno = 3,
             .final_status = Result::OK,
-            .function_name = "ExitNormally",
             .full_function_description = "ExitNormally(int)",
             .modify_policy =
                 [](PolicyBuilder* builder) {
@@ -228,14 +245,30 @@ INSTANTIATE_TEST_SUITE_P(
                 },
         },
         TestCase{
-            .arg = "4",
+            .testname = "SleepForXSeconds",
+            .testno = 4,
             .final_status = Result::TIMEOUT,
-            .function_name = "SleepForXSeconds",
             .full_function_description = "SleepForXSeconds(int)",
             .wall_time_limit = absl::Seconds(1),
+        },
+        TestCase{
+            .testname = "ViolatePolicyRecursive",
+            .testno = 2,
+            .testmode = 2,
+            .final_status = Result::VIOLATION,
+            .function_name = "ViolatePolicy",
+            .full_function_description = "ViolatePolicy(int)",
+        },
+        TestCase{
+            .testname = "ViolatePolicyRecursiveLib",
+            .testno = 2,
+            .testmode = 3,
+            .final_status = Result::VIOLATION,
+            .function_name = "ViolatePolicy",
+            .full_function_description = "ViolatePolicy(int)",
         }),
     [](const ::testing::TestParamInfo<TestCase>& info) {
-      return info.param.function_name;
+      return info.param.testname;
     });
 
 }  // namespace

sandboxed_api/sandbox2/testcases/BUILD.bazel

@@ -163,6 +163,22 @@ cc_binary(
     features = ["fully_static_link"],
 )
 
+cc_library(
+    name = "symbolize_lib",
+    testonly = True,
+    srcs = ["symbolize_lib.cc"],
+    hdrs = ["symbolize_lib.h"],
+    copts = sapi_platform_copts([
+        "-fno-omit-frame-pointer",
+        "-fno-unwind-tables",
+        "-fno-asynchronous-unwind-tables",
+    ]),
+    features = ["fully_static_link"],
+    deps = [
+        "@com_google_absl//absl/base:core_headers",
+    ],
+)
+
 cc_binary(
     name = "symbolize",
     testonly = True,
@@ -170,6 +186,7 @@ cc_binary(
     copts = sapi_platform_copts(),
     features = ["fully_static_link"],
     deps = [
+        ":symbolize_lib",
         "//sandboxed_api/util:raw_logging",
         "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/strings",

sandboxed_api/sandbox2/testcases/CMakeLists.txt

@@ -213,6 +213,24 @@ target_link_libraries(sandbox2_testcase_symbolize PRIVATE
   absl::strings
   sapi::base
   sapi::raw_logging
+  sandbox2::testcase_symbolize_lib
+)
+
+# sandboxed_api/sandbox2/testcases:symbolize_lib
+add_library(sandbox2_testcase_symbolize_lib
+  symbolize_lib.cc
+  symbolize_lib.h
+)
+add_library(sandbox2::testcase_symbolize_lib ALIAS sandbox2_testcase_symbolize_lib)
+target_link_libraries(sandbox2_testcase_symbolize_lib PRIVATE
+  -static
+  absl::core_headers
+  sapi::base
+)
+target_compile_options(sandbox2_testcase_symbolize_lib PRIVATE
+  -fno-omit-frame-pointer
+  -fno-unwind-tables
+  -fno-asynchronous-unwind-tables
 )
 
 # sandboxed_api/sandbox2/testcases:starve

sandboxed_api/sandbox2/testcases/symbolize.cc

@@ -22,6 +22,7 @@
 
 #include "absl/base/attributes.h"
 #include "absl/strings/numbers.h"
+#include "sandboxed_api/sandbox2/testcases/symbolize_lib.h"
 #include "sandboxed_api/util/raw_logging.h"
 
 // Sometimes we don't have debug info to properly unwind through libc (a frame
@@ -63,10 +64,9 @@ void SleepForXSeconds(int x = 0) {
   IndirectLibcCall([x]() { sleep(x); });
 }
 
-int main(int argc, char* argv[]) {
-  SAPI_RAW_CHECK(argc >= 2, "Not enough arguments");
-  int testno;
-  SAPI_RAW_CHECK(absl::SimpleAtoi(argv[1], &testno), "testno not a number");
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void RunTest(int testno) {
   switch (testno) {
     case 1:
       CrashMe();
@@ -83,5 +83,46 @@ int main(int argc, char* argv[]) {
     default:
       SAPI_RAW_LOG(FATAL, "Unknown test case: %d", testno);
   }
+}
+
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void RecurseA(int testno, int n);
+
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void RecurseB(int testno, int n) {
+  if (n > 1) {
+    return RecurseA(testno, n - 1);
+  }
+  return RunTest(testno);
+}
+
+void RecurseA(int testno, int n) {
+  if (n > 1) {
+    return RecurseB(testno, n - 1);
+  }
+  return RunTest(testno);
+}
+
+int main(int argc, char* argv[]) {
+  SAPI_RAW_CHECK(argc >= 3, "Not enough arguments");
+  int testno;
+  int testmode;
+  SAPI_RAW_CHECK(absl::SimpleAtoi(argv[1], &testno), "testno not a number");
+  SAPI_RAW_CHECK(absl::SimpleAtoi(argv[2], &testmode), "testmode not a number");
+  switch (testmode) {
+    case 1:
+      RunTest(testno);
+      break;
+    case 2:
+      RecurseA(testno, 10);
+      break;
+    case 3:
+      LibRecurse(&RunTest, testno, 10);
+      break;
+    default:
+      SAPI_RAW_LOG(FATAL, "Unknown test mode: %d", testmode);
+  }
   return EXIT_SUCCESS;
 }

sandboxed_api/sandbox2/testcases/symbolize_lib.cc

@@ -0,0 +1,25 @@
+#include "sandboxed_api/sandbox2/testcases/symbolize_lib.h"
+
+#include "absl/base/attributes.h"
+
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void LibRecurseA(void (*cb)(int), int data, int n);
+
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void LibRecurseB(void (*cb)(int), int data, int n) {
+  if (n > 1) {
+    return LibRecurseA(cb, data, n - 1);
+  }
+  return cb(data);
+}
+
+void LibRecurseA(void (*cb)(int), int data, int n) {
+  if (n > 1) {
+    return LibRecurseB(cb, data, n - 1);
+  }
+  return cb(data);
+}
+
+void LibRecurse(void (*cb)(int), int data, int n) { LibRecurseA(cb, data, n); }

sandboxed_api/sandbox2/testcases/symbolize_lib.h

@@ -0,0 +1,10 @@
+#ifndef SANDBOXED_API_SANDBOX2_TESTCASES_SYMBOLIZE_LIB_H_
+#define SANDBOXED_API_SANDBOX2_TESTCASES_SYMBOLIZE_LIB_H_
+
+#include "absl/base/attributes.h"
+
+ABSL_ATTRIBUTE_NOINLINE
+ABSL_ATTRIBUTE_NO_TAIL_CALL
+void LibRecurse(void (*cb)(int), int data, int n);
+
+#endif  // SANDBOXED_API_SANDBOX2_TESTCASES_SYMBOLIZE_LIB_H_