gvisor/test/syscalls/linux/arch_prctl.cc

49 lines
1.5 KiB
C++

// 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 <asm/prctl.h>
#include <sys/prctl.h>
#include "gtest/gtest.h"
#include "test/util/test_util.h"
// glibc does not provide a prototype for arch_prctl() so declare it here.
extern "C" int arch_prctl(int code, uintptr_t addr);
namespace gvisor {
namespace testing {
namespace {
TEST(ArchPrctlTest, GetSetFS) {
uintptr_t orig;
const uintptr_t kNonCanonicalFsbase = 0x4141414142424242;
// Get the original FS.base and then set it to the same value (this is
// intentional because FS.base is the TLS pointer so we cannot change it
// arbitrarily).
ASSERT_THAT(arch_prctl(ARCH_GET_FS, reinterpret_cast<uintptr_t>(&orig)),
SyscallSucceeds());
ASSERT_THAT(arch_prctl(ARCH_SET_FS, orig), SyscallSucceeds());
// Trying to set FS.base to a non-canonical value should return an error.
ASSERT_THAT(arch_prctl(ARCH_SET_FS, kNonCanonicalFsbase),
SyscallFailsWithErrno(EPERM));
}
} // namespace
} // namespace testing
} // namespace gvisor