Open source system call tests.

PiperOrigin-RevId: 224886231
Change-Id: I0fccb4d994601739d8b16b1d4e6b31f40297fb22

1 files changed, 146 insertions, 0 deletions

diff --git a/test/syscalls/linux/exceptions.cc b/test/syscalls/linux/exceptions.cc
new file mode 100644
index 000000000..72ab354e3
--- /dev/null
+++ b/test/syscalls/linux/exceptions.cc
@@ -0,0 +1,146 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <signal.h>
+
+#include "gtest/gtest.h"
+#include "test/util/logging.h"
+#include "test/util/signal_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+void inline Halt() { asm("hlt\r\n"); }
+
+void inline SetAlignmentCheck() {
+  asm("pushf\r\n"
+      "pop %%rax\r\n"
+      "or $0x40000, %%rax\r\n"
+      "push %%rax\r\n"
+      "popf\r\n"
+      :
+      :
+      : "ax");
+}
+
+void inline ClearAlignmentCheck() {
+  asm("pushf\r\n"
+      "pop %%rax\r\n"
+      "mov $0x40000, %%rbx\r\n"
+      "not %%rbx\r\n"
+      "and %%rbx, %%rax\r\n"
+      "push %%rax\r\n"
+      "popf\r\n"
+      :
+      :
+      : "ax", "bx");
+}
+
+void inline Int3Normal() { asm(".byte 0xcd, 0x03\r\n"); }
+
+void inline Int3Compact() { asm(".byte 0xcc\r\n"); }
+
+TEST(ExceptionTest, Halt) {
+  // In order to prevent the regular handler from messing with things (and
+  // perhaps refaulting until some other signal occurs), we reset the handler to
+  // the default action here and ensure that it dies correctly.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGSEGV, sa));
+
+  EXPECT_EXIT(Halt(), ::testing::KilledBySignal(SIGSEGV), "");
+}
+
+TEST(ExceptionTest, DivideByZero) {
+  // See above.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGFPE, sa));
+
+  EXPECT_EXIT(
+      {
+        uint32_t remainder;
+        uint32_t quotient;
+        uint32_t divisor = 0;
+        uint64_t value = 1;
+        asm("divl 0(%2)\r\n"
+            : "=d"(remainder), "=a"(quotient)
+            : "r"(&divisor), "d"(value >> 32), "a"(value));
+        TEST_CHECK(quotient > 0);  // Force dependency.
+      },
+      ::testing::KilledBySignal(SIGFPE), "");
+}
+
+TEST(ExceptionTest, Alignment) {
+  SetAlignmentCheck();
+  ClearAlignmentCheck();
+}
+
+TEST(ExceptionTest, AlignmentHalt) {
+  // See above.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGSEGV, sa));
+
+  // Reported upstream. We need to ensure that bad flags are cleared even in
+  // fault paths. Set the alignment flag and then generate an exception.
+  EXPECT_EXIT(
+      {
+        SetAlignmentCheck();
+        Halt();
+      },
+      ::testing::KilledBySignal(SIGSEGV), "");
+}
+
+TEST(ExceptionTest, AlignmentCheck) {
+
+  // See above.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGBUS, sa));
+
+  EXPECT_EXIT(
+      {
+        char array[16];
+        SetAlignmentCheck();
+        for (int i = 0; i < 8; i++) {
+          // At least 7/8 offsets will be unaligned here.
+          uint64_t* ptr = reinterpret_cast<uint64_t*>(&array[i]);
+          asm("mov %0, 0(%0)\r\n" : : "r"(ptr) : "ax");
+        }
+      },
+      ::testing::KilledBySignal(SIGBUS), "");
+}
+
+TEST(ExceptionTest, Int3Normal) {
+  // See above.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGTRAP, sa));
+
+  EXPECT_EXIT(Int3Normal(), ::testing::KilledBySignal(SIGTRAP), "");
+}
+
+TEST(ExceptionTest, Int3Compact) {
+  // See above.
+  struct sigaction sa = {};
+  sa.sa_handler = SIG_DFL;
+  auto const cleanup = ASSERT_NO_ERRNO_AND_VALUE(ScopedSigaction(SIGTRAP, sa));
+
+  EXPECT_EXIT(Int3Compact(), ::testing::KilledBySignal(SIGTRAP), "");
+}
+
+}  // namespace testing
+}  // namespace gvisor