1 files changed, 113 insertions, 0 deletions
diff --git a/test/syscalls/linux/sysret.cc b/test/syscalls/linux/sysret.cc
new file mode 100644
index 000000000..8e10220eb
--- /dev/null
+++ b/test/syscalls/linux/sysret.cc
@@ -0,0 +1,113 @@
+// 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.
+
+// Tests to verify that the behavior of linux and gvisor matches when
+// 'sysret' returns to bad (aka non-canonical) %rip or %rsp.
+#include <sys/ptrace.h>
+#include <sys/user.h>
+
+#include "gtest/gtest.h"
+#include "test/util/logging.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+constexpr uint64_t kNonCanonicalRip = 0xCCCC000000000000;
+constexpr uint64_t kNonCanonicalRsp = 0xFFFF000000000000;
+
+class SysretTest : public ::testing::Test {
+ protected:
+  struct user_regs_struct regs_;
+  pid_t child_;
+
+  void SetUp() override {
+    pid_t pid = fork();
+
+    // Child.
+    if (pid == 0) {
+      TEST_PCHECK(ptrace(PTRACE_TRACEME, 0, 0, 0) == 0);
+      MaybeSave();
+      TEST_PCHECK(raise(SIGSTOP) == 0);
+      MaybeSave();
+      _exit(0);
+    }
+
+    // Parent.
+    int status;
+    ASSERT_THAT(pid, SyscallSucceeds());  // Might still be < 0.
+    ASSERT_THAT(waitpid(pid, &status, 0), SyscallSucceedsWithValue(pid));
+    EXPECT_TRUE(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);
+    ASSERT_THAT(ptrace(PTRACE_GETREGS, pid, 0, &regs_), SyscallSucceeds());
+
+    child_ = pid;
+  }
+
+  void Detach() {
+    ASSERT_THAT(ptrace(PTRACE_DETACH, child_, 0, 0), SyscallSucceeds());
+  }
+
+  void SetRip(uint64_t newrip) {
+    regs_.rip = newrip;
+    ASSERT_THAT(ptrace(PTRACE_SETREGS, child_, 0, &regs_), SyscallSucceeds());
+  }
+
+  void SetRsp(uint64_t newrsp) {
+    regs_.rsp = newrsp;
+    ASSERT_THAT(ptrace(PTRACE_SETREGS, child_, 0, &regs_), SyscallSucceeds());
+  }
+
+  // Wait waits for the child pid and returns the exit status.
+  int Wait() {
+    int status;
+    while (true) {
+      int rval = wait4(child_, &status, 0, NULL);
+      if (rval < 0) {
+        return rval;
+      }
+      if (rval == child_) {
+        return status;
+      }
+    }
+  }
+};
+
+TEST_F(SysretTest, JustDetach) {
+  Detach();
+  int status = Wait();
+  EXPECT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0)
+      << "status = " << status;
+}
+
+TEST_F(SysretTest, BadRip) {
+  SetRip(kNonCanonicalRip);
+  Detach();
+  int status = Wait();
+  EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGSEGV)
+      << "status = " << status;
+}
+
+TEST_F(SysretTest, BadRsp) {
+  SetRsp(kNonCanonicalRsp);
+  Detach();
+  int status = Wait();
+  EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGBUS)
+      << "status = " << status;
+}
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor