- /* Copyright (c) 2018, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #ifndef OPENSSL_HEADER_ABI_TEST_H
- #define OPENSSL_HEADER_ABI_TEST_H
-
- #include <gtest/gtest.h>
-
- #include <string>
- #include <type_traits>
- #include <vector>
-
- #include <openssl/base.h>
-
- #include "../internal.h"
-
-
- // abi_test provides routines for verifying that functions satisfy platform ABI
- // requirements.
- namespace abi_test {
-
- // Result stores the result of an ABI test.
- struct Result {
- bool ok() const { return errors.empty(); }
-
- std::vector<std::string> errors;
- };
-
- namespace internal {
-
- // DeductionGuard wraps |T| in a template, so that template argument deduction
- // does not apply to it. This may be used to force C++ to deduce template
- // arguments from another parameter.
- template <typename T>
- struct DeductionGuard {
- using Type = T;
- };
-
- // Reg128 contains storage space for a 128-bit register.
- struct alignas(16) Reg128 {
- bool operator==(const Reg128 &x) const { return x.lo == lo && x.hi == hi; }
- bool operator!=(const Reg128 &x) const { return !((*this) == x); }
- uint64_t lo, hi;
- };
-
- // LOOP_CALLER_STATE_REGISTERS is a macro that iterates over all registers the
- // callee is expected to save for the caller, with the exception of the stack
- // pointer. The stack pointer is tested implicitly by the function successfully
- // returning at all.
- #if defined(OPENSSL_X86_64)
-
- // References:
- // SysV64: https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-1.0.pdf
- // Win64: https://docs.microsoft.com/en-us/cpp/build/x64-software-conventions?view=vs-2017#register-usage
- #if defined(OPENSSL_WINDOWS)
- #define LOOP_CALLER_STATE_REGISTERS() \
- CALLER_STATE_REGISTER(uint64_t, rbx) \
- CALLER_STATE_REGISTER(uint64_t, rbp) \
- CALLER_STATE_REGISTER(uint64_t, rdi) \
- CALLER_STATE_REGISTER(uint64_t, rsi) \
- CALLER_STATE_REGISTER(uint64_t, r12) \
- CALLER_STATE_REGISTER(uint64_t, r13) \
- CALLER_STATE_REGISTER(uint64_t, r14) \
- CALLER_STATE_REGISTER(uint64_t, r15) \
- CALLER_STATE_REGISTER(Reg128, xmm6) \
- CALLER_STATE_REGISTER(Reg128, xmm7) \
- CALLER_STATE_REGISTER(Reg128, xmm8) \
- CALLER_STATE_REGISTER(Reg128, xmm9) \
- CALLER_STATE_REGISTER(Reg128, xmm10) \
- CALLER_STATE_REGISTER(Reg128, xmm11) \
- CALLER_STATE_REGISTER(Reg128, xmm12) \
- CALLER_STATE_REGISTER(Reg128, xmm13) \
- CALLER_STATE_REGISTER(Reg128, xmm14) \
- CALLER_STATE_REGISTER(Reg128, xmm15)
- #else
- #define LOOP_CALLER_STATE_REGISTERS() \
- CALLER_STATE_REGISTER(uint64_t, rbx) \
- CALLER_STATE_REGISTER(uint64_t, rbp) \
- CALLER_STATE_REGISTER(uint64_t, r12) \
- CALLER_STATE_REGISTER(uint64_t, r13) \
- CALLER_STATE_REGISTER(uint64_t, r14) \
- CALLER_STATE_REGISTER(uint64_t, r15)
- #endif // OPENSSL_WINDOWS
-
- #elif defined(OPENSSL_X86)
-
- // References:
- // SysV32: https://uclibc.org/docs/psABI-i386.pdf and
- // Win32: https://docs.microsoft.com/en-us/cpp/cpp/argument-passing-and-naming-conventions?view=vs-2017
- #define LOOP_CALLER_STATE_REGISTERS() \
- CALLER_STATE_REGISTER(uint32_t, esi) \
- CALLER_STATE_REGISTER(uint32_t, edi) \
- CALLER_STATE_REGISTER(uint32_t, ebx) \
- CALLER_STATE_REGISTER(uint32_t, ebp)
-
- #elif defined(OPENSSL_ARM)
-
- // References:
- // AAPCS: http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042f/IHI0042F_aapcs.pdf
- // iOS32: https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARMv6FunctionCallingConventions.html
- //
- // ARM specifies a common calling convention, except r9 is left to the
- // platform. Linux and iOS differ in handling of r9. iOS's behavior is defined
- // below. We found no clear reference for Linux but observed behavior from
- // LLVM. iOS 3+ treats r9 as caller-saved, while Linux treats it as
- // callee-saved. Most of our assembly treats it as callee-saved to be uniform,
- // but we match the platform to avoid false positives when testing
- // compiler-generated output.
- #define LOOP_CALLER_STATE_REGISTERS_PRE_R9() \
- CALLER_STATE_REGISTER(uint64_t, d8) \
- CALLER_STATE_REGISTER(uint64_t, d9) \
- CALLER_STATE_REGISTER(uint64_t, d10) \
- CALLER_STATE_REGISTER(uint64_t, d11) \
- CALLER_STATE_REGISTER(uint64_t, d12) \
- CALLER_STATE_REGISTER(uint64_t, d13) \
- CALLER_STATE_REGISTER(uint64_t, d14) \
- CALLER_STATE_REGISTER(uint64_t, d15) \
- CALLER_STATE_REGISTER(uint32_t, r4) \
- CALLER_STATE_REGISTER(uint32_t, r5) \
- CALLER_STATE_REGISTER(uint32_t, r6) \
- CALLER_STATE_REGISTER(uint32_t, r7) \
- CALLER_STATE_REGISTER(uint32_t, r8)
- #define LOOP_CALLER_STATE_REGISTERS_POST_R9() \
- CALLER_STATE_REGISTER(uint32_t, r10) \
- CALLER_STATE_REGISTER(uint32_t, r11)
- #if defined(OPENSSL_APPLE)
- #define LOOP_CALLER_STATE_REGISTERS() \
- LOOP_CALLER_STATE_REGISTERS_PRE_R9() \
- LOOP_CALLER_STATE_REGISTERS_POST_R9()
- #else // !OPENSSL_APPLE
- #define LOOP_CALLER_STATE_REGISTERS() \
- LOOP_CALLER_STATE_REGISTERS_PRE_R9() \
- CALLER_STATE_REGISTER(uint32_t, r9) \
- LOOP_CALLER_STATE_REGISTERS_POST_R9()
- #endif // OPENSSL_APPLE
-
- #elif defined(OPENSSL_AARCH64)
-
- // References:
- // AAPCS64: http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055b/IHI0055B_aapcs64.pdf
- // iOS64: https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARM64FunctionCallingConventions.html
- //
- // In aarch64, r19 (x19 in a 64-bit context) is the platform register. iOS says
- // user code may not touch it. We found no clear reference for Linux. The iOS
- // behavior implies portable assembly cannot use it, and aarch64 has many
- // registers. Thus this framework ignores register's existence. We can test r19
- // violations with grep.
- #define LOOP_CALLER_STATE_REGISTERS() \
- /* Per AAPCS64, section 5.1.2, only the bottom 64 bits of v8-v15 */ \
- /* are preserved. These are accessed as dN. */ \
- CALLER_STATE_REGISTER(uint64_t, d8) \
- CALLER_STATE_REGISTER(uint64_t, d9) \
- CALLER_STATE_REGISTER(uint64_t, d10) \
- CALLER_STATE_REGISTER(uint64_t, d11) \
- CALLER_STATE_REGISTER(uint64_t, d12) \
- CALLER_STATE_REGISTER(uint64_t, d13) \
- CALLER_STATE_REGISTER(uint64_t, d14) \
- CALLER_STATE_REGISTER(uint64_t, d15) \
- /* For consistency with dN, use the 64-bit name xN, rather than */ \
- /* the generic rN. */ \
- CALLER_STATE_REGISTER(uint64_t, x19) \
- CALLER_STATE_REGISTER(uint64_t, x20) \
- CALLER_STATE_REGISTER(uint64_t, x21) \
- CALLER_STATE_REGISTER(uint64_t, x22) \
- CALLER_STATE_REGISTER(uint64_t, x23) \
- CALLER_STATE_REGISTER(uint64_t, x24) \
- CALLER_STATE_REGISTER(uint64_t, x25) \
- CALLER_STATE_REGISTER(uint64_t, x26) \
- CALLER_STATE_REGISTER(uint64_t, x27) \
- CALLER_STATE_REGISTER(uint64_t, x28) \
- CALLER_STATE_REGISTER(uint64_t, x29)
-
- #endif // X86_64 || X86 || ARM || AARCH64
-
- // Enable ABI testing if all of the following are true.
- //
- // - We have CallerState and trampoline support for the architecture.
- //
- // - Assembly is enabled.
- //
- // - This is not a shared library build. Assembly functions are not reachable
- // from tests in shared library builds.
- #if defined(LOOP_CALLER_STATE_REGISTERS) && !defined(OPENSSL_NO_ASM) && \
- !defined(BORINGSSL_SHARED_LIBRARY)
- #define SUPPORTS_ABI_TEST
-
- // CallerState contains all caller state that the callee is expected to
- // preserve.
- struct CallerState {
- #define CALLER_STATE_REGISTER(type, name) type name;
- LOOP_CALLER_STATE_REGISTERS()
- #undef CALLER_STATE_REGISTER
- };
-
- // RunTrampoline runs |func| on |argv|, recording ABI errors in |out|. It does
- // not perform any type-checking. If |unwind| is true and unwind tests have been
- // enabled, |func| is single-stepped under an unwind test.
- crypto_word_t RunTrampoline(Result *out, crypto_word_t func,
- const crypto_word_t *argv, size_t argc,
- bool unwind);
-
- template <typename T>
- inline crypto_word_t ToWord(T t) {
- #if !defined(OPENSSL_X86) && !defined(OPENSSL_X86_64) && \
- !defined(OPENSSL_ARM) && !defined(OPENSSL_AARCH64)
- #error "Unknown architecture"
- #endif
- static_assert(sizeof(T) <= sizeof(crypto_word_t),
- "T is larger than crypto_word_t");
- static_assert(sizeof(T) >= 4, "types under four bytes are complicated");
-
- // ABIs are complex around arguments that are smaller than native words. For
- // 32-bit architectures, the rules above imply we only have word-sized
- // arguments. For 64-bit architectures, we still have assembly functions which
- // take |int|.
- //
- // For aarch64, AAPCS64, section 5.4.2, clauses C.7 and C.14 says any
- // remaining bits are unspecified. iOS64 contradicts this and says the callee
- // extends arguments up to 32 bits, and only the upper 32 bits are
- // unspecified. Rejecting parameters smaller than 32 bits avoids the
- // divergence.
- //
- // TODO(davidben): Find authoritative citations for x86_64. For x86_64, I
- // observed the behavior of Clang, GCC, and MSVC. ABI rules here may be
- // inferred from two kinds of experiments:
- //
- // 1. When passing a value to a small-argument-taking function, does the
- // compiler ensure unused bits are cleared, sign-extended, etc.? Tests for
- // register parameters are confounded by x86_64's implicit clearing of
- // registers' upper halves, but passing some_u64 >> 1 usually clears this.
- //
- // 2. When compiling a small-argument-taking function, does the compiler make
- // assumptions about unused bits of arguments?
- //
- // MSVC for x86_64 is straightforward. It appears to tolerate and produce
- // arbitrary values for unused bits, like AAPCS64.
- //
- // GCC and Clang for x86_64 are more complex. They match MSVC for stack
- // parameters. However, for register parameters, they behave like iOS64 and,
- // as callers, extend up to 32 bits, leaving the remainder arbitrary. When
- // compiling a callee, Clang takes advantage of this conversion, but I was
- // unable to make GCC do so.
- //
- // Note that, although the Win64 rules are sufficient to require our assembly
- // be conservative, we wish for |CHECK_ABI| to support C-compiled functions,
- // so it must enforce the correct rules for each platform.
- //
- // Fortunately, the |static_assert|s above cause all supported architectures
- // to behave the same.
- crypto_word_t ret;
- // Filling extra bits with 0xaa will be vastly out of bounds for code
- // expecting either sign- or zero-extension. (0xaa is 0b10101010.)
- OPENSSL_memset(&ret, 0xaa, sizeof(ret));
- OPENSSL_memcpy(&ret, &t, sizeof(t));
- return ret;
- }
-
- // CheckImpl runs |func| on |args|, recording ABI errors in |out|. If |unwind|
- // is true and unwind tests have been enabled, |func| is single-stepped under an
- // unwind test.
- //
- // It returns the value as a |crypto_word_t| to work around problems when |R| is
- // void. |args| is wrapped in a |DeductionGuard| so |func| determines the
- // template arguments. Otherwise, |args| may deduce |Args| incorrectly. For
- // instance, if |func| takes const int *, and the caller passes an int *, the
- // compiler will complain the deduced types do not match.
- template <typename R, typename... Args>
- inline crypto_word_t CheckImpl(Result *out, bool unwind, R (*func)(Args...),
- typename DeductionGuard<Args>::Type... args) {
- // We only support up to 8 arguments. This ensures all arguments on aarch64
- // are passed in registers and avoids the iOS descrepancy around packing small
- // arguments on the stack.
- //
- // https://developer.apple.com/library/archive/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARM64FunctionCallingConventions.html
- static_assert(sizeof...(args) <= 8,
- "too many arguments for abi_test_trampoline");
-
- // Allocate one extra entry so MSVC does not complain about zero-size arrays.
- crypto_word_t argv[sizeof...(args) + 1] = {
- ToWord(args)...,
- };
- return RunTrampoline(out, reinterpret_cast<crypto_word_t>(func), argv,
- sizeof...(args), unwind);
- }
- #else
- // To simplify callers when ABI testing support is unavoidable, provide a backup
- // CheckImpl implementation. It must be specialized for void returns because we
- // call |func| directly.
- template <typename R, typename... Args>
- inline typename std::enable_if<!std::is_void<R>::value, crypto_word_t>::type
- CheckImpl(Result *out, bool /* unwind */, R (*func)(Args...),
- typename DeductionGuard<Args>::Type... args) {
- *out = Result();
- return func(args...);
- }
-
- template <typename... Args>
- inline crypto_word_t CheckImpl(Result *out, bool /* unwind */,
- void (*func)(Args...),
- typename DeductionGuard<Args>::Type... args) {
- *out = Result();
- func(args...);
- return 0;
- }
- #endif // SUPPORTS_ABI_TEST
-
- // FixVAArgsString takes a string like "f, 1, 2" and returns a string like
- // "f(1, 2)".
- //
- // This is needed because the |CHECK_ABI| macro below cannot be defined as
- // CHECK_ABI(func, ...). The C specification requires that variadic macros bind
- // at least one variadic argument. Clang, GCC, and MSVC all ignore this, but
- // there are issues with trailing commas and different behaviors across
- // compilers.
- std::string FixVAArgsString(const char *str);
-
- // CheckGTest behaves like |CheckImpl|, but it returns the correct type and
- // raises GTest assertions on failure. If |unwind| is true and unwind tests are
- // enabled, |func| is single-stepped under an unwind test.
- template <typename R, typename... Args>
- inline R CheckGTest(const char *va_args_str, const char *file, int line,
- bool unwind, R (*func)(Args...),
- typename DeductionGuard<Args>::Type... args) {
- Result result;
- crypto_word_t ret = CheckImpl(&result, unwind, func, args...);
- if (!result.ok()) {
- testing::Message msg;
- msg << "ABI failures in " << FixVAArgsString(va_args_str) << ":\n";
- for (const auto &error : result.errors) {
- msg << " " << error << "\n";
- }
- ADD_FAILURE_AT(file, line) << msg;
- }
- return (R)ret;
- }
-
- } // namespace internal
-
- // Check runs |func| on |args| and returns the result. If ABI-testing is
- // supported in this build configuration, it writes any ABI failures to |out|.
- // Otherwise, it runs the function transparently.
- template <typename R, typename... Args>
- inline R Check(Result *out, R (*func)(Args...),
- typename internal::DeductionGuard<Args>::Type... args) {
- return (R)internal::CheckImpl(out, false, func, args...);
- }
-
- // EnableUnwindTests enables unwind tests, if supported. If not supported, it
- // does nothing.
- void EnableUnwindTests();
-
- // UnwindTestsEnabled returns true if unwind tests are enabled and false
- // otherwise.
- bool UnwindTestsEnabled();
-
- } // namespace abi_test
-
- // CHECK_ABI calls the first argument on the remaining arguments and returns the
- // result. If ABI-testing is supported in this build configuration, it adds a
- // non-fatal GTest failure if the call did not satisfy ABI requirements.
- //
- // |CHECK_ABI| does return the value and thus may replace any function call,
- // provided it takes only simple parameters. However, it is recommended to test
- // ABI separately from functional tests of assembly. Fully instrumenting a
- // function for ABI checking requires single-stepping the function, which is
- // inefficient.
- //
- // Functional testing requires coverage of input values, while ABI testing only
- // requires branch coverage. Most of our assembly is constant-time, so usually
- // only a few instrumented calls are necessary.
- //
- // TODO(https://crbug.com/boringssl/259): Most of Windows assembly currently
- // fails SEH testing. For now, |CHECK_ABI| behaves like |CHECK_ABI_NO_UNWIND|
- // on Windows. Functions which work with unwind testing on Windows should use
- // |CHECK_ABI_SEH|.
- #if defined(OPENSSL_WINDOWS)
- #define CHECK_ABI(...) CHECK_ABI_NO_UNWIND(__VA_ARGS__)
- #else
- #define CHECK_ABI(...) CHECK_ABI_SEH(__VA_ARGS__)
- #endif
-
- // CHECK_ABI_SEH behaves like |CHECK_ABI| but enables unwind testing on Windows.
- #define CHECK_ABI_SEH(...) \
- abi_test::internal::CheckGTest(#__VA_ARGS__, __FILE__, __LINE__, true, \
- __VA_ARGS__)
-
- // CHECK_ABI_NO_UNWIND behaves like |CHECK_ABI| but disables unwind testing.
- #define CHECK_ABI_NO_UNWIND(...) \
- abi_test::internal::CheckGTest(#__VA_ARGS__, __FILE__, __LINE__, false, \
- __VA_ARGS__)
-
-
- // Internal functions.
-
- #if defined(SUPPORTS_ABI_TEST)
- struct Uncallable {
- Uncallable() = delete;
- };
-
- extern "C" {
-
- // abi_test_trampoline loads callee-saved registers from |state|, calls |func|
- // with |argv|, then saves the callee-saved registers into |state|. It returns
- // the result of |func|. If |unwind| is non-zero, this function triggers unwind
- // instrumentation.
- //
- // We give |func| type |crypto_word_t| to avoid tripping MSVC's warning 4191.
- crypto_word_t abi_test_trampoline(crypto_word_t func,
- abi_test::internal::CallerState *state,
- const crypto_word_t *argv, size_t argc,
- crypto_word_t unwind);
-
- #if defined(OPENSSL_X86_64)
- // abi_test_unwind_start points at the instruction that starts unwind testing in
- // |abi_test_trampoline|. This is the value of the instruction pointer at the
- // first |SIGTRAP| during unwind testing.
- //
- // This symbol is not a function and should not be called.
- void abi_test_unwind_start(Uncallable);
-
- // abi_test_unwind_return points at the instruction immediately after the call in
- // |abi_test_trampoline|. When unwinding the function under test, this is the
- // expected address in the |abi_test_trampoline| frame. After this address, the
- // unwind tester should ignore |SIGTRAP| until |abi_test_unwind_stop|.
- //
- // This symbol is not a function and should not be called.
- void abi_test_unwind_return(Uncallable);
-
- // abi_test_unwind_stop is the value of the instruction pointer at the final
- // |SIGTRAP| during unwind testing.
- //
- // This symbol is not a function and should not be called.
- void abi_test_unwind_stop(Uncallable);
-
- // abi_test_bad_unwind_wrong_register preserves the ABI, but annotates the wrong
- // register in unwind metadata.
- void abi_test_bad_unwind_wrong_register(void);
-
- // abi_test_bad_unwind_temporary preserves the ABI, but temporarily corrupts the
- // storage space for a saved register, breaking unwind.
- void abi_test_bad_unwind_temporary(void);
-
- #if defined(OPENSSL_WINDOWS)
- // abi_test_bad_unwind_epilog preserves the ABI, and correctly annotates the
- // prolog, but the epilog does not match Win64's rules, breaking unwind during
- // the epilog.
- void abi_test_bad_unwind_epilog(void);
- #endif
- #endif // OPENSSL_X86_64
-
- #if defined(OPENSSL_X86_64) || defined(OPENSSL_X86)
- // abi_test_get_and_clear_direction_flag clears the direction flag. If the flag
- // was previously set, it returns one. Otherwise, it returns zero.
- int abi_test_get_and_clear_direction_flag(void);
-
- // abi_test_set_direction_flag sets the direction flag. This does not conform to
- // ABI requirements and must only be called within a |CHECK_ABI| guard to avoid
- // errors later in the program.
- int abi_test_set_direction_flag(void);
- #endif // OPENSSL_X86_64 || OPENSSL_X86
-
- } // extern "C"
- #endif // SUPPORTS_ABI_TEST
-
-
- #endif // OPENSSL_HEADER_ABI_TEST_H
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