// Copyright 2018 The gVisor Authors. // // 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. #define _GNU_SOURCE 1 #include <signal.h> #include <ucontext.h> #include <unistd.h> #include "gtest/gtest.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { __attribute__((noinline)) void Fault(void) { volatile int* foo = nullptr; *foo = 0; } int GetPcFromUcontext(ucontext_t* uc, uintptr_t* pc) { #if defined(__x86_64__) *pc = uc->uc_mcontext.gregs[REG_RIP]; return 1; #elif defined(__i386__) *pc = uc->uc_mcontext.gregs[REG_EIP]; return 1; #elif defined(__aarch64__) *pc = uc->uc_mcontext.pc; return 1; #else return 0; #endif } void sigact_handler(int sig, siginfo_t* siginfo, void* context) { uintptr_t pc; if (GetPcFromUcontext(reinterpret_cast<ucontext_t*>(context), &pc)) { /* Expect Fault() to be at most 64 bytes in size. */ uintptr_t fault_addr = reinterpret_cast<uintptr_t>(&Fault); EXPECT_GE(pc, fault_addr); EXPECT_LT(pc, fault_addr + 64); exit(0); } } TEST(FaultTest, InRange) { // Reset the signal handler to do nothing so that it doesn't freak out // the test runner when we fire an alarm. struct sigaction sa = {}; sa.sa_sigaction = sigact_handler; sigfillset(&sa.sa_mask); sa.sa_flags = SA_SIGINFO; ASSERT_THAT(sigaction(SIGSEGV, &sa, nullptr), SyscallSucceeds()); Fault(); } } // namespace } // namespace testing } // namespace gvisor