From 498595d54347d711dbd24247ed12c659b9d89c58 Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Mon, 9 Dec 2019 11:21:01 -0800 Subject: Add tests for rseq(2) Add a decent set of syscall tests for rseq(2). These are a bit awkward because of issues with library integration. libc may register rseq on thread start (including before main on the initial thread), precluding much testing. Thus we run tests in a libc-free subprocess. Support for rseq(2) in gVisor will come in a later commit. PiperOrigin-RevId: 284595994 --- test/syscalls/BUILD | 2 + test/syscalls/linux/BUILD | 16 ++ test/syscalls/linux/rseq.cc | 198 +++++++++++++++++++ test/syscalls/linux/rseq/BUILD | 59 ++++++ test/syscalls/linux/rseq/critical.S | 66 +++++++ test/syscalls/linux/rseq/critical.h | 39 ++++ test/syscalls/linux/rseq/rseq.cc | 366 ++++++++++++++++++++++++++++++++++++ test/syscalls/linux/rseq/start.S | 45 +++++ test/syscalls/linux/rseq/syscalls.h | 66 +++++++ test/syscalls/linux/rseq/test.h | 43 +++++ test/syscalls/linux/rseq/types.h | 31 +++ test/syscalls/linux/rseq/uapi.h | 54 ++++++ 12 files changed, 985 insertions(+) create mode 100644 test/syscalls/linux/rseq.cc create mode 100644 test/syscalls/linux/rseq/BUILD create mode 100644 test/syscalls/linux/rseq/critical.S create mode 100644 test/syscalls/linux/rseq/critical.h create mode 100644 test/syscalls/linux/rseq/rseq.cc create mode 100644 test/syscalls/linux/rseq/start.S create mode 100644 test/syscalls/linux/rseq/syscalls.h create mode 100644 test/syscalls/linux/rseq/test.h create mode 100644 test/syscalls/linux/rseq/types.h create mode 100644 test/syscalls/linux/rseq/uapi.h (limited to 'test') diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 6650984fa..829693e8e 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -376,6 +376,8 @@ syscall_test( syscall_test(test = "//test/syscalls/linux:rlimits_test") +syscall_test(test = "//test/syscalls/linux:rseq_test") + syscall_test(test = "//test/syscalls/linux:rtsignal_test") syscall_test(test = "//test/syscalls/linux:sched_test") diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 61f310db9..c49445d62 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1852,6 +1852,22 @@ cc_binary( ], ) +cc_binary( + name = "rseq_test", + testonly = 1, + srcs = ["rseq.cc"], + data = ["//test/syscalls/linux/rseq"], + linkstatic = 1, + deps = [ + "//test/syscalls/linux/rseq:lib", + "//test/util:logging", + "//test/util:multiprocess_util", + "//test/util:test_main", + "//test/util:test_util", + "@com_google_googletest//:gtest", + ], +) + cc_binary( name = "rtsignal_test", testonly = 1, diff --git a/test/syscalls/linux/rseq.cc b/test/syscalls/linux/rseq.cc new file mode 100644 index 000000000..106c045e3 --- /dev/null +++ b/test/syscalls/linux/rseq.cc @@ -0,0 +1,198 @@ +// Copyright 2019 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 +#include +#include +#include +#include +#include + +#include "gtest/gtest.h" +#include "test/syscalls/linux/rseq/test.h" +#include "test/syscalls/linux/rseq/uapi.h" +#include "test/util/logging.h" +#include "test/util/multiprocess_util.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +// Syscall test for rseq (restartable sequences). +// +// We must be very careful about how these tests are written. Each thread may +// only have one struct rseq registration, which may be done automatically at +// thread start (as of 2019-11-13, glibc does *not* support rseq and thus does +// not do so). +// +// Testing of rseq is thus done primarily in a child process with no +// registration. This means exec'ing a nostdlib binary, as rseq registration can +// only be cleared by execve (or knowing the old rseq address), and glibc (based +// on the current unmerged patches) register rseq before calling main()). + +int RSeq(struct rseq* rseq, uint32_t rseq_len, int flags, uint32_t sig) { + return syscall(kRseqSyscall, rseq, rseq_len, flags, sig); +} + +// Returns true if this kernel supports the rseq syscall. +PosixErrorOr RSeqSupported() { + // We have to be careful here, there are three possible cases: + // + // 1. rseq is not supported -> ENOSYS + // 2. rseq is supported and not registered -> success, but we should + // unregister. + // 3. rseq is supported and registered -> EINVAL (most likely). + + // The only validation done on new registrations is that rseq is aligned and + // writable. + rseq rseq = {}; + int ret = RSeq(&rseq, sizeof(rseq), 0, 0); + if (ret == 0) { + // Successfully registered, rseq is supported. Unregister. + ret = RSeq(&rseq, sizeof(rseq), kRseqFlagUnregister, 0); + if (ret != 0) { + return PosixError(errno); + } + return true; + } + + switch (errno) { + case ENOSYS: + // Not supported. + return false; + case EINVAL: + // Supported, but already registered. EINVAL returned because we provided + // a different address. + return true; + default: + // Unknown error. + return PosixError(errno); + } +} + +constexpr char kRseqBinary[] = "test/syscalls/linux/rseq/rseq"; + +void RunChildTest(std::string test_case, int want_status) { + std::string path = RunfilePath(kRseqBinary); + + pid_t child_pid = -1; + int execve_errno = 0; + auto cleanup = ASSERT_NO_ERRNO_AND_VALUE( + ForkAndExec(path, {path, test_case}, {}, &child_pid, &execve_errno)); + + ASSERT_GT(child_pid, 0); + ASSERT_EQ(execve_errno, 0); + + int status = 0; + ASSERT_THAT(RetryEINTR(waitpid)(child_pid, &status, 0), SyscallSucceeds()); + ASSERT_EQ(status, want_status); +} + +// Test that rseq must be aligned. +TEST(RseqTest, Unaligned) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestUnaligned, 0); +} + +// Sanity test that registration works. +TEST(RseqTest, Register) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestRegister, 0); +} + +// Registration can't be done twice. +TEST(RseqTest, DoubleRegister) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestDoubleRegister, 0); +} + +// Registration can be done again after unregister. +TEST(RseqTest, RegisterUnregister) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestRegisterUnregister, 0); +} + +// The pointer to rseq must match on register/unregister. +TEST(RseqTest, UnregisterDifferentPtr) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestUnregisterDifferentPtr, 0); +} + +// The signature must match on register/unregister. +TEST(RseqTest, UnregisterDifferentSignature) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestUnregisterDifferentSignature, 0); +} + +// The CPU ID is initialized. +TEST(RseqTest, CPU) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestCPU, 0); +} + +// Critical section is eventually aborted. +TEST(RseqTest, Abort) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestAbort, 0); +} + +// Abort may be before the critical section. +TEST(RseqTest, AbortBefore) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestAbortBefore, 0); +} + +// Signature must match. +TEST(RseqTest, AbortSignature) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestAbortSignature, SIGSEGV); +} + +// Abort must not be in the critical section. +TEST(RseqTest, AbortPreCommit) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestAbortPreCommit, SIGSEGV); +} + +// rseq.rseq_cs is cleared on abort. +TEST(RseqTest, AbortClearsCS) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestAbortClearsCS, 0); +} + +// rseq.rseq_cs is cleared on abort outside of critical section. +TEST(RseqTest, InvalidAbortClearsCS) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(RSeqSupported())); + + RunChildTest(kRseqTestInvalidAbortClearsCS, 0); +} + +} // namespace + +} // namespace testing +} // namespace gvisor diff --git a/test/syscalls/linux/rseq/BUILD b/test/syscalls/linux/rseq/BUILD new file mode 100644 index 000000000..5cfe4e56f --- /dev/null +++ b/test/syscalls/linux/rseq/BUILD @@ -0,0 +1,59 @@ +# This package contains a standalone rseq test binary. This binary must not +# depend on libc, which might use rseq itself. + +load("@bazel_tools//tools/cpp:cc_flags_supplier.bzl", "cc_flags_supplier") +load("@rules_cc//cc:defs.bzl", "cc_library") + +package(licenses = ["notice"]) + +genrule( + name = "rseq_binary", + srcs = [ + "critical.h", + "critical.S", + "rseq.cc", + "syscalls.h", + "start.S", + "test.h", + "types.h", + "uapi.h", + ], + outs = ["rseq"], + cmd = " ".join([ + "$(CC)", + "$(CC_FLAGS) ", + "-I.", + "-Wall", + "-Werror", + "-O2", + "-std=c++17", + "-static", + "-nostdlib", + "-ffreestanding", + "-o", + "$(location rseq)", + "$(location critical.S)", + "$(location rseq.cc)", + "$(location start.S)", + ]), + toolchains = [ + ":no_pie_cc_flags", + "@bazel_tools//tools/cpp:current_cc_toolchain", + ], + visibility = ["//:sandbox"], +) + +cc_flags_supplier( + name = "no_pie_cc_flags", + features = ["-pie"], +) + +cc_library( + name = "lib", + testonly = 1, + hdrs = [ + "test.h", + "uapi.h", + ], + visibility = ["//:sandbox"], +) diff --git a/test/syscalls/linux/rseq/critical.S b/test/syscalls/linux/rseq/critical.S new file mode 100644 index 000000000..8c0687e6d --- /dev/null +++ b/test/syscalls/linux/rseq/critical.S @@ -0,0 +1,66 @@ +// Copyright 2019 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. + +// Restartable sequences critical sections. + +// Loops continuously until aborted. +// +// void rseq_loop(struct rseq* r, struct rseq_cs* cs) + + .text + .globl rseq_loop + .type rseq_loop, @function + +rseq_loop: + jmp begin + + // Abort block before the critical section. + // Abort signature is 4 nops for simplicity. + .byte 0x90, 0x90, 0x90, 0x90 + .globl rseq_loop_early_abort +rseq_loop_early_abort: + ret + +begin: + // r->rseq_cs = cs + movq %rsi, 8(%rdi) + + // N.B. rseq_cs will be cleared by any preempt, even outside the critical + // section. Thus it must be set in or immediately before the critical section + // to ensure it is not cleared before the section begins. + .globl rseq_loop_start +rseq_loop_start: + jmp rseq_loop_start + + // "Pre-commit": extra instructions inside the critical section. These are + // used as the abort point in TestAbortPreCommit, which is not valid. + .globl rseq_loop_pre_commit +rseq_loop_pre_commit: + // Extra abort signature + nop for TestAbortPostCommit. + .byte 0x90, 0x90, 0x90, 0x90 + nop + + // "Post-commit": never reached in this case. + .globl rseq_loop_post_commit +rseq_loop_post_commit: + + // Abort signature is 4 nops for simplicity. + .byte 0x90, 0x90, 0x90, 0x90 + + .globl rseq_loop_abort +rseq_loop_abort: + ret + + .size rseq_loop,.-rseq_loop + .section .note.GNU-stack,"",@progbits diff --git a/test/syscalls/linux/rseq/critical.h b/test/syscalls/linux/rseq/critical.h new file mode 100644 index 000000000..ac987a25e --- /dev/null +++ b/test/syscalls/linux/rseq/critical.h @@ -0,0 +1,39 @@ +// Copyright 2019 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_RSEQ_CRITICAL_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_RSEQ_CRITICAL_H_ + +#include "test/syscalls/linux/rseq/types.h" +#include "test/syscalls/linux/rseq/uapi.h" + +constexpr uint32_t kRseqSignature = 0x90909090; + +extern "C" { + +extern void rseq_loop(struct rseq* r, struct rseq_cs* cs); +extern void* rseq_loop_early_abort; +extern void* rseq_loop_start; +extern void* rseq_loop_pre_commit; +extern void* rseq_loop_post_commit; +extern void* rseq_loop_abort; + +extern int rseq_getpid(struct rseq* r, struct rseq_cs* cs); +extern void* rseq_getpid_start; +extern void* rseq_getpid_post_commit; +extern void* rseq_getpid_abort; + +} // extern "C" + +#endif // GVISOR_TEST_SYSCALLS_LINUX_RSEQ_CRITICAL_H_ diff --git a/test/syscalls/linux/rseq/rseq.cc b/test/syscalls/linux/rseq/rseq.cc new file mode 100644 index 000000000..f036db26d --- /dev/null +++ b/test/syscalls/linux/rseq/rseq.cc @@ -0,0 +1,366 @@ +// Copyright 2019 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 "test/syscalls/linux/rseq/critical.h" +#include "test/syscalls/linux/rseq/syscalls.h" +#include "test/syscalls/linux/rseq/test.h" +#include "test/syscalls/linux/rseq/types.h" +#include "test/syscalls/linux/rseq/uapi.h" + +namespace gvisor { +namespace testing { + +extern "C" int main(int argc, char** argv, char** envp); + +// Standalone initialization before calling main(). +extern "C" void __init(uintptr_t* sp) { + int argc = sp[0]; + char** argv = reinterpret_cast(&sp[1]); + char** envp = &argv[argc + 1]; + + // Call main() and exit. + sys_exit_group(main(argc, argv, envp)); + + // sys_exit_group does not return +} + +int strcmp(const char* s1, const char* s2) { + const unsigned char* p1 = reinterpret_cast(s1); + const unsigned char* p2 = reinterpret_cast(s2); + + while (*p1 == *p2) { + if (!*p1) { + return 0; + } + ++p1; + ++p2; + } + return static_cast(*p1) - static_cast(*p2); +} + +int sys_rseq(struct rseq* rseq, uint32_t rseq_len, int flags, uint32_t sig) { + return raw_syscall(kRseqSyscall, rseq, rseq_len, flags, sig); +} + +// Test that rseq must be aligned. +int TestUnaligned() { + constexpr uintptr_t kRequiredAlignment = alignof(rseq); + + char buf[2 * kRequiredAlignment] = {}; + uintptr_t ptr = reinterpret_cast(&buf[0]); + if ((ptr & (kRequiredAlignment - 1)) == 0) { + // buf is already aligned. Misalign it. + ptr++; + } + + int ret = sys_rseq(reinterpret_cast(ptr), sizeof(rseq), 0, 0); + if (sys_errno(ret) != EINVAL) { + return 1; + } + return 0; +} + +// Sanity test that registration works. +int TestRegister() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + return 0; +}; + +// Registration can't be done twice. +int TestDoubleRegister() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != EBUSY) { + return 1; + } + + return 0; +}; + +// Registration can be done again after unregister. +int TestRegisterUnregister() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + + if (int ret = sys_rseq(&r, sizeof(r), kRseqFlagUnregister, 0); + sys_errno(ret) != 0) { + return 1; + } + + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + + return 0; +}; + +// The pointer to rseq must match on register/unregister. +int TestUnregisterDifferentPtr() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + + struct rseq r2 = {}; + if (int ret = sys_rseq(&r2, sizeof(r2), kRseqFlagUnregister, 0); + sys_errno(ret) != EINVAL) { + return 1; + } + + return 0; +}; + +// The signature must match on register/unregister. +int TestUnregisterDifferentSignature() { + constexpr int kSignature = 0; + + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kSignature); sys_errno(ret) != 0) { + return 1; + } + + if (int ret = sys_rseq(&r, sizeof(r), kRseqFlagUnregister, kSignature + 1); + sys_errno(ret) != EPERM) { + return 1; + } + + return 0; +}; + +// The CPU ID is initialized. +int TestCPU() { + struct rseq r = {}; + r.cpu_id = kRseqCPUIDUninitialized; + + if (int ret = sys_rseq(&r, sizeof(r), 0, 0); sys_errno(ret) != 0) { + return 1; + } + + if (__atomic_load_n(&r.cpu_id, __ATOMIC_RELAXED) < 0) { + return 1; + } + if (__atomic_load_n(&r.cpu_id_start, __ATOMIC_RELAXED) < 0) { + return 1; + } + + return 0; +}; + +// Critical section is eventually aborted. +int TestAbort() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_abort); + + // Loops until abort. If this returns then abort occurred. + rseq_loop(&r, &cs); + + return 0; +}; + +// Abort may be before the critical section. +int TestAbortBefore() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_early_abort); + + // Loops until abort. If this returns then abort occurred. + rseq_loop(&r, &cs); + + return 0; +}; + +// Signature must match. +int TestAbortSignature() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature + 1); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_abort); + + // Loops until abort. This should SIGSEGV on abort. + rseq_loop(&r, &cs); + + return 1; +}; + +// Abort must not be in the critical section. +int TestAbortPreCommit() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature + 1); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_pre_commit); + + // Loops until abort. This should SIGSEGV on abort. + rseq_loop(&r, &cs); + + return 1; +}; + +// rseq.rseq_cs is cleared on abort. +int TestAbortClearsCS() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_abort); + + // Loops until abort. If this returns then abort occurred. + rseq_loop(&r, &cs); + + if (__atomic_load_n(&r.rseq_cs, __ATOMIC_RELAXED)) { + return 1; + } + + return 0; +}; + +// rseq.rseq_cs is cleared on abort outside of critical section. +int TestInvalidAbortClearsCS() { + struct rseq r = {}; + if (int ret = sys_rseq(&r, sizeof(r), 0, kRseqSignature); + sys_errno(ret) != 0) { + return 1; + } + + struct rseq_cs cs = {}; + cs.version = 0; + cs.flags = 0; + cs.start_ip = reinterpret_cast(&rseq_loop_start); + cs.post_commit_offset = reinterpret_cast(&rseq_loop_post_commit) - + reinterpret_cast(&rseq_loop_start); + cs.abort_ip = reinterpret_cast(&rseq_loop_abort); + + __atomic_store_n(&r.rseq_cs, &cs, __ATOMIC_RELAXED); + + // When the next abort condition occurs, the kernel will clear cs once it + // determines we aren't in the critical section. + while (1) { + if (!__atomic_load_n(&r.rseq_cs, __ATOMIC_RELAXED)) { + break; + } + } + + return 0; +}; + +// Exit codes: +// 0 - Pass +// 1 - Fail +// 2 - Missing argument +// 3 - Unknown test case +extern "C" int main(int argc, char** argv, char** envp) { + if (argc != 2) { + // Usage: rseq + return 2; + } + + if (strcmp(argv[1], kRseqTestUnaligned) == 0) { + return TestUnaligned(); + } + if (strcmp(argv[1], kRseqTestRegister) == 0) { + return TestRegister(); + } + if (strcmp(argv[1], kRseqTestDoubleRegister) == 0) { + return TestDoubleRegister(); + } + if (strcmp(argv[1], kRseqTestRegisterUnregister) == 0) { + return TestRegisterUnregister(); + } + if (strcmp(argv[1], kRseqTestUnregisterDifferentPtr) == 0) { + return TestUnregisterDifferentPtr(); + } + if (strcmp(argv[1], kRseqTestUnregisterDifferentSignature) == 0) { + return TestUnregisterDifferentSignature(); + } + if (strcmp(argv[1], kRseqTestCPU) == 0) { + return TestCPU(); + } + if (strcmp(argv[1], kRseqTestAbort) == 0) { + return TestAbort(); + } + if (strcmp(argv[1], kRseqTestAbortBefore) == 0) { + return TestAbortBefore(); + } + if (strcmp(argv[1], kRseqTestAbortSignature) == 0) { + return TestAbortSignature(); + } + if (strcmp(argv[1], kRseqTestAbortPreCommit) == 0) { + return TestAbortPreCommit(); + } + if (strcmp(argv[1], kRseqTestAbortClearsCS) == 0) { + return TestAbortClearsCS(); + } + if (strcmp(argv[1], kRseqTestInvalidAbortClearsCS) == 0) { + return TestInvalidAbortClearsCS(); + } + + return 3; +} + +} // namespace testing +} // namespace gvisor diff --git a/test/syscalls/linux/rseq/start.S b/test/syscalls/linux/rseq/start.S new file mode 100644 index 000000000..b9611b276 --- /dev/null +++ b/test/syscalls/linux/rseq/start.S @@ -0,0 +1,45 @@ +// Copyright 2019 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. + + + .text + .align 4 + .type _start,@function + .globl _start + +_start: + movq %rsp,%rdi + call __init + hlt + + .size _start,.-_start + .section .note.GNU-stack,"",@progbits + + .text + .globl raw_syscall + .type raw_syscall, @function + +raw_syscall: + mov %rdi,%rax // syscall # + mov %rsi,%rdi // arg0 + mov %rdx,%rsi // arg1 + mov %rcx,%rdx // arg2 + mov %r8,%r10 // arg3 (goes in r10 instead of rcx for system calls) + mov %r9,%r8 // arg4 + mov 0x8(%rsp),%r9 // arg5 + syscall + ret + + .size raw_syscall,.-raw_syscall + .section .note.GNU-stack,"",@progbits diff --git a/test/syscalls/linux/rseq/syscalls.h b/test/syscalls/linux/rseq/syscalls.h new file mode 100644 index 000000000..e5299c188 --- /dev/null +++ b/test/syscalls/linux/rseq/syscalls.h @@ -0,0 +1,66 @@ +// Copyright 2019 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_RSEQ_SYSCALLS_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_RSEQ_SYSCALLS_H_ + +#include "test/syscalls/linux/rseq/types.h" + +#ifdef __x86_64__ +// Syscall numbers. +constexpr int kGetpid = 39; +constexpr int kExitGroup = 231; +#else +#error "Unknown architecture" +#endif + +namespace gvisor { +namespace testing { + +// Standalone system call interfaces. +// Note that these are all "raw" system call interfaces which encode +// errors by setting the return value to a small negative number. +// Use sys_errno() to check system call return values for errors. + +// Maximum Linux error number. +constexpr int kMaxErrno = 4095; + +// Errno values. +#define EPERM 1 +#define EFAULT 14 +#define EBUSY 16 +#define EINVAL 22 + +// Get the error number from a raw system call return value. +// Returns a positive error number or 0 if there was no error. +static inline int sys_errno(uintptr_t rval) { + if (rval >= static_cast(-kMaxErrno)) { + return -static_cast(rval); + } + return 0; +} + +extern "C" uintptr_t raw_syscall(int number, ...); + +static inline void sys_exit_group(int status) { + raw_syscall(kExitGroup, status); +} +static inline int sys_getpid() { + return static_cast(raw_syscall(kGetpid)); +} + +} // namespace testing +} // namespace gvisor + +#endif // GVISOR_TEST_SYSCALLS_LINUX_RSEQ_SYSCALLS_H_ diff --git a/test/syscalls/linux/rseq/test.h b/test/syscalls/linux/rseq/test.h new file mode 100644 index 000000000..3b7bb74b1 --- /dev/null +++ b/test/syscalls/linux/rseq/test.h @@ -0,0 +1,43 @@ +// Copyright 2019 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TEST_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TEST_H_ + +namespace gvisor { +namespace testing { + +// Test cases supported by rseq binary. + +inline constexpr char kRseqTestUnaligned[] = "unaligned"; +inline constexpr char kRseqTestRegister[] = "register"; +inline constexpr char kRseqTestDoubleRegister[] = "double-register"; +inline constexpr char kRseqTestRegisterUnregister[] = "register-unregister"; +inline constexpr char kRseqTestUnregisterDifferentPtr[] = + "unregister-different-ptr"; +inline constexpr char kRseqTestUnregisterDifferentSignature[] = + "unregister-different-signature"; +inline constexpr char kRseqTestCPU[] = "cpu"; +inline constexpr char kRseqTestAbort[] = "abort"; +inline constexpr char kRseqTestAbortBefore[] = "abort-before"; +inline constexpr char kRseqTestAbortSignature[] = "abort-signature"; +inline constexpr char kRseqTestAbortPreCommit[] = "abort-precommit"; +inline constexpr char kRseqTestAbortClearsCS[] = "abort-clears-cs"; +inline constexpr char kRseqTestInvalidAbortClearsCS[] = + "invalid-abort-clears-cs"; + +} // namespace testing +} // namespace gvisor + +#endif // GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TEST_H_ diff --git a/test/syscalls/linux/rseq/types.h b/test/syscalls/linux/rseq/types.h new file mode 100644 index 000000000..b6afe9817 --- /dev/null +++ b/test/syscalls/linux/rseq/types.h @@ -0,0 +1,31 @@ +// Copyright 2019 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TYPES_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TYPES_H_ + +using size_t = __SIZE_TYPE__; +using uintptr_t = __UINTPTR_TYPE__; + +using uint8_t = __UINT8_TYPE__; +using uint16_t = __UINT16_TYPE__; +using uint32_t = __UINT32_TYPE__; +using uint64_t = __UINT64_TYPE__; + +using int8_t = __INT8_TYPE__; +using int16_t = __INT16_TYPE__; +using int32_t = __INT32_TYPE__; +using int64_t = __INT64_TYPE__; + +#endif // GVISOR_TEST_SYSCALLS_LINUX_RSEQ_TYPES_H_ diff --git a/test/syscalls/linux/rseq/uapi.h b/test/syscalls/linux/rseq/uapi.h new file mode 100644 index 000000000..e3ff0579a --- /dev/null +++ b/test/syscalls/linux/rseq/uapi.h @@ -0,0 +1,54 @@ +// Copyright 2019 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_RSEQ_UAPI_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_RSEQ_UAPI_H_ + +// User-kernel ABI for restartable sequences. + +// Standard types. +// +// N.B. This header will be included in targets that do have the standard +// library, so we can't shadow the standard type names. +using __u32 = __UINT32_TYPE__; +using __u64 = __UINT64_TYPE__; + +#ifdef __x86_64__ +// Syscall numbers. +constexpr int kRseqSyscall = 334; +#else +#error "Unknown architecture" +#endif // __x86_64__ + +struct rseq_cs { + __u32 version; + __u32 flags; + __u64 start_ip; + __u64 post_commit_offset; + __u64 abort_ip; +} __attribute__((aligned(4 * sizeof(__u64)))); + +// N.B. alignment is enforced by the kernel. +struct rseq { + __u32 cpu_id_start; + __u32 cpu_id; + struct rseq_cs* rseq_cs; + __u32 flags; +} __attribute__((aligned(4 * sizeof(__u64)))); + +constexpr int kRseqFlagUnregister = 1 << 0; + +constexpr int kRseqCPUIDUninitialized = -1; + +#endif // GVISOR_TEST_SYSCALLS_LINUX_RSEQ_UAPI_H_ -- cgit v1.2.3