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// 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.
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <cerrno>
#include <csignal>
#include "gtest/gtest.h"
#include "test/util/cleanup.h"
#include "test/util/logging.h"
#include "test/util/posix_error.h"
#include "test/util/signal_util.h"
#include "test/util/test_util.h"
namespace gvisor {
namespace testing {
namespace {
// saved_info is set by the handler.
siginfo_t saved_info;
// has_saved_info is set to true by the handler.
volatile bool has_saved_info;
void SigHandler(int sig, siginfo_t* info, void* context) {
// Copy to the given info.
saved_info = *info;
has_saved_info = true;
}
void ClearSavedInfo() {
// Clear the cached info.
memset(&saved_info, 0, sizeof(saved_info));
has_saved_info = false;
}
PosixErrorOr<Cleanup> SetupSignalHandler(int sig) {
struct sigaction sa;
sa.sa_sigaction = SigHandler;
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
return ScopedSigaction(sig, sa);
}
class RtSignalTest : public ::testing::Test {
protected:
void SetUp() override {
action_cleanup_ = ASSERT_NO_ERRNO_AND_VALUE(SetupSignalHandler(SIGUSR1));
mask_cleanup_ =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGUSR1));
}
void TearDown() override { ClearSavedInfo(); }
private:
Cleanup action_cleanup_;
Cleanup mask_cleanup_;
};
static int rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t* uinfo) {
int ret;
do {
// NOTE(b/25434735): rt_sigqueueinfo(2) could return EAGAIN for RT signals.
ret = syscall(SYS_rt_sigqueueinfo, tgid, sig, uinfo);
} while (ret == -1 && errno == EAGAIN);
return ret;
}
TEST_F(RtSignalTest, InvalidTID) {
siginfo_t uinfo;
// Depending on the kernel version, these calls may fail with
// ESRCH (goobunutu machines) or EPERM (production machines). Thus,
// the test simply ensures that they do fail.
EXPECT_THAT(rt_sigqueueinfo(-1, SIGUSR1, &uinfo), SyscallFails());
EXPECT_FALSE(has_saved_info);
EXPECT_THAT(rt_sigqueueinfo(0, SIGUSR1, &uinfo), SyscallFails());
EXPECT_FALSE(has_saved_info);
}
TEST_F(RtSignalTest, InvalidCodes) {
siginfo_t uinfo;
// We need a child for the code checks to apply. If the process is delivering
// to itself, then it can use whatever codes it wants and they will go
// through.
pid_t child = fork();
if (child == 0) {
_exit(1);
}
ASSERT_THAT(child, SyscallSucceeds());
// These are not allowed for child processes.
uinfo.si_code = 0; // SI_USER.
EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
SyscallFailsWithErrno(EPERM));
uinfo.si_code = 0x80; // SI_KERNEL.
EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
SyscallFailsWithErrno(EPERM));
uinfo.si_code = -6; // SI_TKILL.
EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo),
SyscallFailsWithErrno(EPERM));
uinfo.si_code = -1; // SI_QUEUE (allowed).
EXPECT_THAT(rt_sigqueueinfo(child, SIGUSR1, &uinfo), SyscallSucceeds());
// Join the child process.
EXPECT_THAT(waitpid(child, nullptr, 0), SyscallSucceeds());
}
TEST_F(RtSignalTest, ValueDelivered) {
siginfo_t uinfo;
uinfo.si_code = -1; // SI_QUEUE (allowed).
uinfo.si_errno = 0x1234;
EXPECT_EQ(saved_info.si_errno, 0x0);
EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR1, &uinfo), SyscallSucceeds());
EXPECT_TRUE(has_saved_info);
EXPECT_EQ(saved_info.si_errno, 0x1234);
}
TEST_F(RtSignalTest, SignoMatch) {
auto action2_cleanup = ASSERT_NO_ERRNO_AND_VALUE(SetupSignalHandler(SIGUSR2));
auto mask2_cleanup =
ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_UNBLOCK, SIGUSR2));
siginfo_t uinfo;
uinfo.si_code = -1; // SI_QUEUE (allowed).
EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR1, &uinfo), SyscallSucceeds());
EXPECT_TRUE(has_saved_info);
EXPECT_EQ(saved_info.si_signo, SIGUSR1);
ClearSavedInfo();
EXPECT_THAT(rt_sigqueueinfo(getpid(), SIGUSR2, &uinfo), SyscallSucceeds());
EXPECT_TRUE(has_saved_info);
EXPECT_EQ(saved_info.si_signo, SIGUSR2);
}
} // namespace
} // namespace testing
} // namespace gvisor
int main(int argc, char** argv) {
// These tests depend on delivering SIGUSR1/2 to the main thread (so they can
// synchronously check has_saved_info). Block these so that any other threads
// created by TestInit will also have them blocked.
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGUSR1);
sigaddset(&set, SIGUSR2);
TEST_PCHECK(sigprocmask(SIG_BLOCK, &set, nullptr) == 0);
gvisor::testing::TestInit(&argc, &argv);
return gvisor::testing::RunAllTests();
}
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