================ @@ -0,0 +1,155 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +// clang-format off + +// REQUIRES: target={{aarch64.*}} +// UNSUPPORTED: target={{.*-windows.*}} + +// The libSystem unwinder does not correctly read UNW_AARCH64_RA_SIGN_STATE, at +// least through OS version 27.0 +// XFAIL: stdlib=apple-libc++ && target={{.*}}-apple-{{.*}}{{(11|12|13|14|15|26)(\.\d+)?}} +// XFAIL: stdlib=apple-libc++ && target={{.*}}-apple-{{.*}}27.0 + +// clang-format on + +#undef NDEBUG +#include "../src/config.h" +#include "support/func_bounds.h" +#include <assert.h> +#include <inttypes.h> +#include <libunwind.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <unistd.h> +#include <unwind.h> + +#if defined(__APPLE__) +#include <sys/sysctl.h> +#endif +#if defined(_LIBUNWIND_HAVE_GETAUXVAL) || defined(_LIBUNWIND_HAVE_ELF_AUX_INFO) +#include <sys/auxv.h> +#endif + +// Note: This test requires FEAT_PAuth (and is setup to pass on other targets). + +#if defined(__APPLE__) +static bool checkHasPAuth() { + int has_pauth = 0; + size_t size = sizeof(has_pauth); + if (sysctlbyname("hw.optional.arm.FEAT_PAuth", &has_pauth, &size, NULL, 0)) + return false; + return has_pauth != 0; +} +#elif defined(_LIBUNWIND_HAVE_GETAUXVAL) +static bool checkHasPAuth() { + constexpr unsigned long hwcap_paca = (1UL << 30); + unsigned long hwcap = getauxval(AT_HWCAP); + return (hwcap & hwcap_paca) != 0; +} +#elif defined(_LIBUNWIND_HAVE_ELF_AUX_INFO) +static bool checkHasPAuth() { + constexpr unsigned long hwcap_paca = (1UL << 30); + unsigned long hwcap = 0; + elf_aux_info(AT_HWCAP, &hwcap, sizeof(hwcap)); + return (hwcap & hwcap_paca) != 0; +} +#else +static bool checkHasPAuth() { + // TODO: Support other platforms. + return false; +} +#endif + +FUNC_BOUNDS_DECL(main_func); + +_Unwind_Reason_Code frame_handler(struct _Unwind_Context *ctx, void *arg) { + uint64_t ra_sign_state = + (uint64_t)_Unwind_GetGR(ctx, UNW_AARCH64_RA_SIGN_STATE); + + uintptr_t ip = _Unwind_GetIP(ctx); + if (ip >= (uintptr_t)FUNC_START(main_func) && + ip < (uintptr_t)FUNC_END(main_func)) { + + // Collect the RA from the callee that will return to main. + *(uint64_t *)arg = ra_sign_state; + + // Unwind until main is reached, above frames depend on the platform and + // architecture. + return _URC_END_OF_STACK; + } + +#if defined(__PTRAUTH__) || __has_feature(ptrauth_calls) + assert(ra_sign_state == 1); +#else + assert(ra_sign_state == 0); +#endif + + return _URC_NO_REASON; +} + +__attribute__((noinline)) extern "C" uintptr_t +get_main_ra_sign_state(const char *note) { + printf("check: %s\n", note); + uint64_t sign_state = -1; + _Unwind_Backtrace(frame_handler, &sign_state); + printf("UNW_AARCH64_RA_SIGN_STATE for %s = %" PRIu64 "\n", note, sign_state); + assert((sign_state & 0x3) == sign_state); + return sign_state; +} + +__attribute__((noinline)) uint64_t check_vanilla(const char *note) { + return get_main_ra_sign_state(note); +} + +__attribute__((naked, target("pauth"))) uint64_t +check_negate(const char *note) { + // clang-format off + asm(".cfi_negate_ra_state\n" + "pacibsp\n" + + "stp x29, x30, [sp, #-16]!\n" + ".cfi_def_cfa_offset 16\n" + ".cfi_offset x29, -16\n" + ".cfi_offset x30, -8\n" + + "bl " SYMBOL_NAME(get_main_ra_sign_state) "\n" ---------------- kovdan01 wrote:
Do I get it right that here we rely on the fact that `note` pointer remains in the same `x0` register and gets passed to `get_main_ra_sign_state`? If so, I'm wondering do we actually have such a guarantee. It's probably not that important since it just about debug printing, but anyway if we can make this more robust (for example, explicitly set `x0` in inline assembly registers set list) - it's probably worth doing that. https://github.com/llvm/llvm-project/pull/205188 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
