From patchwork Sat Jul 13 06:51:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Xing, Cedric" X-Patchwork-Id: 11042909 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 67BCC912 for ; Sat, 13 Jul 2019 06:51:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54FE7284F5 for ; Sat, 13 Jul 2019 06:51:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4920228541; Sat, 13 Jul 2019 06:51:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3C159284F5 for ; Sat, 13 Jul 2019 06:51:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726274AbfGMGvc (ORCPT ); Sat, 13 Jul 2019 02:51:32 -0400 Received: from mga11.intel.com ([192.55.52.93]:55269 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727490AbfGMGvb (ORCPT ); Sat, 13 Jul 2019 02:51:31 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Jul 2019 23:51:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,485,1557212400"; d="scan'208";a="318200508" Received: from bxing-ubuntu.jf.intel.com ([10.23.30.27]) by orsmga004.jf.intel.com with ESMTP; 12 Jul 2019 23:51:27 -0700 From: Cedric Xing To: linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, jarkko.sakkinen@linux.intel.com Cc: cedric.xing@intel.com, akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, kai.svahn@intel.com, kai.huang@intel.com Subject: [RFC PATCH v4 3/3] selftests/x86/sgx: Augment SGX selftest to test vDSO API Date: Fri, 12 Jul 2019 23:51:27 -0700 Message-Id: <657fe13cbf962d72dc1afc0e25577d8e89225702.1563000446.git.cedric.xing@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch augments SGX selftest with two new tests. The first test exercises the newly added callback interface, by marking the whole enclave range as PROT_READ, then calling mprotect() upon #PFs to add necessary PTE permissions per PFEC (#PF Error Code) until the enclave finishes. This test also serves as an example to demonstrate the callback interface. The second test single-steps through __vdso_sgx_enter_enclave() to make sure the call stack can be unwound at every instruction within that vDSO API. Its purpose is to validate the hand-crafted CFI directives in the assembly. Besides the new tests, this patch also fixes minor problems in the Makefile, such as: * appended "--build-id=none" to ld command line to suppress the ".note.gnu.build-id section discarded" linker warning. * removed "--remove-section=.got.plt" from objcopy command line as that section would never exist in statically linked (enclave) images. Signed-off-by: Cedric Xing --- tools/testing/selftests/x86/sgx/Makefile | 6 +- tools/testing/selftests/x86/sgx/main.c | 344 ++++++++++++++++++--- tools/testing/selftests/x86/sgx/sgx_call.S | 40 ++- 3 files changed, 343 insertions(+), 47 deletions(-) diff --git a/tools/testing/selftests/x86/sgx/Makefile b/tools/testing/selftests/x86/sgx/Makefile index 3af15d7c8644..31f937e220c4 100644 --- a/tools/testing/selftests/x86/sgx/Makefile +++ b/tools/testing/selftests/x86/sgx/Makefile @@ -14,16 +14,16 @@ TEST_CUSTOM_PROGS := $(OUTPUT)/test_sgx all_64: $(TEST_CUSTOM_PROGS) $(TEST_CUSTOM_PROGS): main.c sgx_call.S $(OUTPUT)/encl_piggy.o - $(CC) $(HOST_CFLAGS) -o $@ $^ + $(CC) $(HOST_CFLAGS) -o $@ $^ -lunwind -ldl -Wl,--defsym,__image_base=0 -pie $(OUTPUT)/encl_piggy.o: encl_piggy.S $(OUTPUT)/encl.bin $(OUTPUT)/encl.ss $(CC) $(HOST_CFLAGS) -I$(OUTPUT) -c $< -o $@ $(OUTPUT)/encl.bin: $(OUTPUT)/encl.elf - objcopy --remove-section=.got.plt -O binary $< $@ + objcopy -O binary $< $@ $(OUTPUT)/encl.elf: encl.lds encl.c encl_bootstrap.S - $(CC) $(ENCL_CFLAGS) -T $^ -o $@ + $(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none $(OUTPUT)/encl.ss: $(OUTPUT)/sgxsign signing_key.pem $(OUTPUT)/encl.bin $^ $@ diff --git a/tools/testing/selftests/x86/sgx/main.c b/tools/testing/selftests/x86/sgx/main.c index e2265f841fb0..e47d6c32623f 100644 --- a/tools/testing/selftests/x86/sgx/main.c +++ b/tools/testing/selftests/x86/sgx/main.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) // Copyright(c) 2016-18 Intel Corporation. +#define _GNU_SOURCE #include #include #include @@ -9,16 +10,31 @@ #include #include #include +#include #include #include #include -#include +#include +#include +#include + +#define UNW_LOCAL_ONLY +#include + #include "encl_piggy.h" #include "defines.h" #include "../../../../../arch/x86/kernel/cpu/sgx/arch.h" #include "../../../../../arch/x86/include/uapi/asm/sgx.h" -static const uint64_t MAGIC = 0x1122334455667788ULL; +#define _Q(x) __Q(x) +#define __Q(x) #x +#define ERRLN "Line " _Q(__LINE__) + +#define X86_EFLAGS_TF (1ul << 8) + +extern char __image_base[]; +size_t eenter; +static size_t vdso_base; struct vdso_symtab { Elf64_Sym *elf_symtab; @@ -26,20 +42,11 @@ struct vdso_symtab { Elf64_Word *elf_hashtab; }; -static void *vdso_get_base_addr(char *envp[]) +static void vdso_init(void) { - Elf64_auxv_t *auxv; - int i; - - for (i = 0; envp[i]; i++); - auxv = (Elf64_auxv_t *)&envp[i + 1]; - - for (i = 0; auxv[i].a_type != AT_NULL; i++) { - if (auxv[i].a_type == AT_SYSINFO_EHDR) - return (void *)auxv[i].a_un.a_val; - } - - return NULL; + vdso_base = getauxval(AT_SYSINFO_EHDR); + if (!vdso_base) + exit(1); } static Elf64_Dyn *vdso_get_dyntab(void *addr) @@ -66,8 +73,9 @@ static void *vdso_get_dyn(void *addr, Elf64_Dyn *dyntab, Elf64_Sxword tag) return NULL; } -static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) +static bool vdso_get_symtab(struct vdso_symtab *symtab) { + void *addr = (void *)vdso_base; Elf64_Dyn *dyntab = vdso_get_dyntab(addr); symtab->elf_symtab = vdso_get_dyn(addr, dyntab, DT_SYMTAB); @@ -138,7 +146,7 @@ static bool encl_create(int dev_fd, unsigned long bin_size, base = mmap(NULL, secs->size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_SHARED, dev_fd, 0); if (base == MAP_FAILED) { - perror("mmap"); + perror(ERRLN); return false; } @@ -224,35 +232,292 @@ static bool encl_load(struct sgx_secs *secs, unsigned long bin_size) return false; } -void sgx_call(void *rdi, void *rsi, void *tcs, - struct sgx_enclave_exception *exception, - void *eenter); +int sgx_call(void *rdi, void *rsi, long rdx, void *rcx, void *r8, void *r9, + void *tcs, struct sgx_enclave_exinfo *ei, void *cb); + +static void show_enclave_exinfo(const struct sgx_enclave_exinfo *exinfop, + const char *header) +{ + static const char * const enclu_leaves[] = { + "EREPORT", + "EGETKEY", + "EENTER", + "ERESUME", + "EEXIT" + }; + static const char * const exception_names[] = { + "#DE", + "#DB", + "NMI", + "#BP", + "#OF", + "#BR", + "#UD", + "#NM", + "#DF", + "CSO", + "#TS", + "#NP", + "#SS", + "#GP", + "#PF", + "Unknown", + "#MF", + "#AC", + "#MC", + "#XM", + "#VE", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown", + "Unknown" + }; + + printf("%s: leaf:%s(%d)", header, + enclu_leaves[exinfop->leaf], exinfop->leaf); + if (exinfop->leaf != 4) + printf(" trap:%s(%d) ec:%d addr:0x%llx\n", + exception_names[exinfop->trapnr], exinfop->trapnr, + exinfop->error_code, exinfop->address); + else + printf("\n"); +} + +static const uint64_t MAGIC = 0x1122334455667788ULL; + +/* + * test1() tests vDSO API (i.e. __vdso_sgx_enter_enclave) without supplying a + * callback function. It loads a very simple enclave that copies a 64-bit + * value from source buffer to the destination. Then it invokes the enclave + * twice. At the first time it provides all valid inputs and verifies the + * output buffer contains the same value as the source buffer. At the second + * time, it provides NULL as the TCS address to exercise the exception flow. + */ +static void test1(struct sgx_secs *secs) +{ + uint64_t result = 0; + struct sgx_enclave_exinfo exinfo; + + printf("[1] Entering the enclave without callback.\n"); + + printf("Input: 0x%lx\n Expect: Same as input\n", MAGIC); + sgx_call((void *)&MAGIC, &result, 0, NULL, NULL, NULL, + (void *)secs->base, &exinfo, NULL); + show_enclave_exinfo(&exinfo, " Exit"); + if (result != MAGIC) { + fprintf(stderr, "0x%lx != 0x%lx\n", result, MAGIC); + exit(1); + } + printf(" Output: 0x%lx\n", result); + + printf("Input: Null TCS\n Expect: #PF at EENTER\n"); + sgx_call((void *)&MAGIC, &result, 0, NULL, NULL, NULL, + NULL, &exinfo, NULL); + show_enclave_exinfo(&exinfo, " Exit"); + if (exinfo.leaf != 2 /*EENTER*/ || exinfo.trapnr != 14 /*#PF*/) + exit(1); +} + +static int test2_callback(long rdi, long rsi, long rdx, + struct sgx_enclave_exinfo *ei, long r8, long r9, + void *tcs, long ursp) +{ + show_enclave_exinfo(ei, " callback"); + + switch (ei->leaf) { + case 4: + return 0; + case 3: + case 2: + switch (ei->trapnr) { + case 1: /*#DB*/ + break; + case 14:/*#PF*/ + if ((ei->error_code & 1) == 0) { + fprintf(stderr, ERRLN + ": Unexpected #PF error code\n"); + exit(1); + } + if (mprotect((void *)(ei->address & -0x1000), 0x1000, + ((ei->error_code & 2) ? PROT_WRITE : 0) | + ((ei->error_code & 0x10) ? PROT_EXEC : 0) | + PROT_READ)) { + perror(ERRLN); + exit(1); + } + break; + default: + fprintf(stderr, ERRLN ": Unexpected exception\n"); + exit(1); + } + return ei->leaf == 2 ? -EAGAIN : ei->leaf; + } + return -EINVAL; +} + +/* + * test2() tests the exception/callback mechanism of the vDSO API with a + * callback function. Firstly, it supplies all valid inputs along with a + * callback function, and verifies that exinfo contains the expected values. + * Secondly, it marks the whole enclave virtual range as read-only, and let the + * callback fixes the PTE permissions by calling mprotect() along the way. The + * callback in this test also serves an example to show how to use the callback + * interface. + */ +static void test2(struct sgx_secs *secs) +{ + uint64_t result = 0; + struct sgx_enclave_exinfo exinfo; + + printf("[2] Entering the enclave with callback.\n"); + + printf("Input: 0x%lx\n Expect: Same as input\n", MAGIC); + sgx_call((void *)&MAGIC, &result, 0, NULL, NULL, NULL, + (void *)secs->base, &exinfo, test2_callback); + if (result != MAGIC) { + fprintf(stderr, "0x%lx != 0x%lx\n", result, MAGIC); + exit(1); + } + printf(" Output: 0x%lx\n", result); + + printf("Input: Read-only enclave (0x%lx-0x%lx)\n" + " Expect: #PFs to be fixed by callback\n", + secs->base, secs->base + (encl_bin_end - encl_bin) - 1); + if (mprotect((void *)secs->base, encl_bin_end - encl_bin, PROT_READ)) { + perror(ERRLN); + exit(1); + } + while (sgx_call((void *)&MAGIC, &result, 0, NULL, NULL, NULL, + (void *)secs->base, &exinfo, test2_callback) == -EAGAIN) + ; + show_enclave_exinfo(&exinfo, " Exit"); + if (exinfo.leaf != 4 /*EEXIT*/) + exit(1); +} + +static void *test3_caller; +static struct test3_proc_context { + unw_word_t ip, bx, sp, bp, r12, r13, r14, r15; +} test3_ctx; -int main(int argc, char *argv[], char *envp[]) +static unw_word_t test3_getcontext(unw_cursor_t *cursor, + struct test3_proc_context *ctxp) +{ + unw_get_reg(cursor, UNW_REG_IP, &ctxp->ip); + unw_get_reg(cursor, UNW_REG_SP, &ctxp->sp); + unw_get_reg(cursor, UNW_X86_64_RBX, &ctxp->bx); + unw_get_reg(cursor, UNW_X86_64_RBP, &ctxp->bp); + unw_get_reg(cursor, UNW_X86_64_R12, &ctxp->r12); + unw_get_reg(cursor, UNW_X86_64_R13, &ctxp->r13); + unw_get_reg(cursor, UNW_X86_64_R14, &ctxp->r14); + unw_get_reg(cursor, UNW_X86_64_R15, &ctxp->r15); + return ctxp->ip; +} + +static void test3_sigtrap(int sig, siginfo_t *info, ucontext_t *ctxp) +{ + static int in_vdso_eenter; + + unw_cursor_t cursor; + unw_context_t uc; + struct test3_proc_context pc; + + if (ctxp->uc_mcontext.gregs[REG_RIP] == eenter) { + in_vdso_eenter = 1; + printf(" trace started at ip:%llx (vdso:0x%llx)\n", + ctxp->uc_mcontext.gregs[REG_RIP], + ctxp->uc_mcontext.gregs[REG_RIP] - vdso_base); + } + + if (!in_vdso_eenter) + return; + + if ((void *)ctxp->uc_mcontext.gregs[REG_RIP] == test3_caller) { + in_vdso_eenter = 0; + ctxp->uc_mcontext.gregs[REG_EFL] &= ~X86_EFLAGS_TF; + printf(" trace ended successfully at ip:%llx (executable:0x%llx)\n", + ctxp->uc_mcontext.gregs[REG_RIP], + ctxp->uc_mcontext.gregs[REG_RIP] - + (size_t)__image_base); + return; + } + + unw_getcontext(&uc); + unw_init_local(&cursor, &uc); + while (unw_step(&cursor) > 0 && + test3_getcontext(&cursor, &pc) != test3_ctx.ip) + ; + + if (memcmp(&pc, &test3_ctx, sizeof(pc))) { + fprintf(stderr, ERRLN ": Error unwinding\n"); + exit(1); + } +} + +__attribute__((noinline)) +static void test3_test_unwind(void (*f)(struct sgx_secs *), + struct sgx_secs *secs) +{ + test3_caller = __builtin_return_address(0); + __asm__ ("pushfq; orl %0, (%%rsp); popfq" : : "i"(X86_EFLAGS_TF)); + f(secs); +} + +/* + * test3() single-steps through the vDSO API to test out CFI directives inside + * the API. + */ +static void test3(struct sgx_secs *secs) +{ + unw_cursor_t cursor; + unw_context_t uc; + struct sigaction sa = { + .sa_sigaction = (void (*)(int, siginfo_t*, void*))test3_sigtrap, + .sa_flags = SA_SIGINFO, + }; + + unw_getcontext(&uc); + unw_init_local(&cursor, &uc); + if (unw_step(&cursor) > 0) + test3_getcontext(&cursor, &test3_ctx); + else { + fprintf(stderr, ERRLN ": error initializing unwind context\n"); + exit(1); + } + + if (sigaction(SIGTRAP, &sa, NULL) < 0) { + perror(ERRLN); + exit(1); + } + + test3_test_unwind(test1, secs); + test3_test_unwind(test2, secs); +} + +int main(void) { unsigned long bin_size = encl_bin_end - encl_bin; unsigned long ss_size = encl_ss_end - encl_ss; - struct sgx_enclave_exception exception; Elf64_Sym *eenter_sym; struct vdso_symtab symtab; struct sgx_secs secs; - uint64_t result = 0; - void *eenter; - void *addr; - - memset(&exception, 0, sizeof(exception)); - addr = vdso_get_base_addr(envp); - if (!addr) - exit(1); + vdso_init(); - if (!vdso_get_symtab(addr, &symtab)) + if (!vdso_get_symtab(&symtab)) exit(1); eenter_sym = vdso_symtab_get(&symtab, "__vdso_sgx_enter_enclave"); if (!eenter_sym) exit(1); - eenter = addr + eenter_sym->st_value; + eenter = vdso_base + eenter_sym->st_value; printf("Binary size %lu (0x%lx), SIGSTRUCT size %lu\n", bin_size, bin_size, ss_size); @@ -266,14 +531,11 @@ int main(int argc, char *argv[], char *envp[]) if (!encl_load(&secs, bin_size)) exit(1); - printf("Input: 0x%lx\n", MAGIC); - sgx_call((void *)&MAGIC, &result, (void *)secs.base, &exception, - eenter); - if (result != MAGIC) { - fprintf(stderr, "0x%lx != 0x%lx\n", result, MAGIC); - exit(1); - } + printf("--- Functional Tests ---\n"); + test1(&secs); + test2(&secs); - printf("Output: 0x%lx\n", result); - exit(0); + printf("--- Unwind Tests ---\n"); + test3(&secs); + return 0; } diff --git a/tools/testing/selftests/x86/sgx/sgx_call.S b/tools/testing/selftests/x86/sgx/sgx_call.S index 14bd0a044199..ca2c0c947758 100644 --- a/tools/testing/selftests/x86/sgx/sgx_call.S +++ b/tools/testing/selftests/x86/sgx/sgx_call.S @@ -7,9 +7,43 @@ .global sgx_call sgx_call: + .cfi_startproc + push %r15 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r15, 0 + push %r14 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r14, 0 + push %r13 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r13, 0 + push %r12 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %r12, 0 push %rbx - mov $0x02, %rax - mov %rdx, %rbx - call *%r8 + .cfi_adjust_cfa_offset 8 + .cfi_rel_offset %rbx, 0 + push $0 + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + push 0x48(%rsp) + .cfi_adjust_cfa_offset 8 + mov $2, %eax + call *eenter(%rip) + add $0x20, %rsp + .cfi_adjust_cfa_offset -0x20 pop %rbx + .cfi_adjust_cfa_offset -8 + pop %r12 + .cfi_adjust_cfa_offset -8 + pop %r13 + .cfi_adjust_cfa_offset -8 + pop %r14 + .cfi_adjust_cfa_offset -8 + pop %r15 + .cfi_adjust_cfa_offset -8 ret + .cfi_endproc