Received: by 2002:a05:7412:5112:b0:fa:6e18:a558 with SMTP id fm18csp1578471rdb; Wed, 24 Jan 2024 22:50:01 -0800 (PST) X-Google-Smtp-Source: AGHT+IGWAfU9Ttf9DwVtwaOZG2Me8Jn2QhSR8NbC3BSiIMquMmu0gDEQtWrs0pUe4XZxpAeSbTFz X-Received: by 2002:a17:903:28c:b0:1d7:7ec4:5899 with SMTP id j12-20020a170903028c00b001d77ec45899mr812791plr.13.1706165401248; Wed, 24 Jan 2024 22:50:01 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1706165401; cv=pass; d=google.com; s=arc-20160816; b=GwhjBLjS3Rlgf1ITeUOYmfmrHXLR8414AnvzTVuc0DCePCcInyZjRMJ1KMoengTe4B B80EwvcuGoGirms+oeqVCnn117JFV+qQnt5+2ifVrQWk34D55/S6bF6WILMTF5roIqix T26xxXbnyzR3sc/Bgk3RmBGuUhA4iD0H2H+mCzWMfbEJmcWjPEqKJAWn9gIhZ/eUmeBQ 9QlBVvBikrMTn6ydUaBFjojDkY//QoJctmjk3klaz92AacCVxo92Gmev9cF1ILKjbx+n 9NnNfL3Q0fTF/iBI8LHEUMroTtkW5NekJUEaLV9ERgR2DUNwPgOGEMzCXgYCbLIrFHIF eRlw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=T7qF2ux/z3bZUzHUpWVLBPHatGr2T7HdgXLVBLlMyVI=; fh=oy7V1wWqiaug32hsWRXm98kKNp5NFPTWbY7PiGr4deM=; b=rFUqiHmcyk1HnVvGLiYS7y19XIqj6GzhcPqBIkXRBCpzI7+6OGe5Lj9kYI5SMiiTeP 09qq/ltSR0APMcn3tHncuMzF6hqEcOpx9zAd94OdXxPa+pktvhoL+51I1fB1B74hMXoM rnkGqI8KC89FGz2fZG0qldiECfZztsHCbWTErPpAZlxzm8IFENNs1qjlfizTD0XxHfB2 gYrGoM+NH8OsOVrCHoI56BreGCMfzcnmjyq2kKV6CA0Ja4GWbdRnvAJ7JVo1ZvfK+u4g 1rJND6Zs9TD9FQT6Oap0g/4dHgai530DCNbif7E9LBqTGFsTPe9IznbETxiPyMKRUtiQ N2aQ== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=SPXJdAKX; arc=pass (i=1 spf=pass spfdomain=rivosinc.com dkim=pass dkdomain=rivosinc-com.20230601.gappssmtp.com); spf=pass (google.com: domain of linux-kernel+bounces-38036-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38036-linux.lists.archive=gmail.com@vger.kernel.org" Return-Path: Received: from sv.mirrors.kernel.org (sv.mirrors.kernel.org. [139.178.88.99]) by mx.google.com with ESMTPS id u4-20020a17090282c400b001d4891f73f0si6750193plz.549.2024.01.24.22.50.01 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jan 2024 22:50:01 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-38036-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99; Authentication-Results: mx.google.com; dkim=pass header.i=@rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=SPXJdAKX; arc=pass (i=1 spf=pass spfdomain=rivosinc.com dkim=pass dkdomain=rivosinc-com.20230601.gappssmtp.com); spf=pass (google.com: domain of linux-kernel+bounces-38036-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) smtp.mailfrom="linux-kernel+bounces-38036-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 00B9328AD8B for ; Thu, 25 Jan 2024 06:38:18 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 120D21CAB7; Thu, 25 Jan 2024 06:30:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="SPXJdAKX" Received: from mail-pg1-f169.google.com (mail-pg1-f169.google.com [209.85.215.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63B661CAA1 for ; Thu, 25 Jan 2024 06:30:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706164242; cv=none; b=nNOTC7zo3TIAT5l5fYT4RH4Op3Zn07wAwLXVv9fbO7cfvSCO1bVFNqkZUVMopkLk2nB6R7j9WfbzN/s8/bkPejw7L1t0Lj/8chuHm53bgDMNCWi5/CFPRJj9ZvS/Ks+SVletgIo6Jw0Snb0jXFCyG6oWcmP/Ikvo8AjxQKx9V7Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706164242; c=relaxed/simple; bh=DjfqDTddf+3ke89A4GPKk4U5WzZ5kAt5r3gG2sX7YzY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sDyFp8yjtQGzf2XefMsRRU1AuKD1NHkptOP/vCQ3eCsERUV82VQqTE+qENi+dbGGI+UC20zIpcL6CKbPuOeKbB87maT9uGXxtpdFe816AjLmuuPaH/JJo53OedGZLPAt41OgCUsr4po68g6lrGo1YMceP6Momc5kUquKv5eOV3w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=SPXJdAKX; arc=none smtp.client-ip=209.85.215.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Received: by mail-pg1-f169.google.com with SMTP id 41be03b00d2f7-5ce74ea4bf2so300535a12.0 for ; Wed, 24 Jan 2024 22:30:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1706164240; x=1706769040; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=T7qF2ux/z3bZUzHUpWVLBPHatGr2T7HdgXLVBLlMyVI=; b=SPXJdAKXUyiCHsrFgm5wmqTRzWmfGtumkhdb/byqw0AcfPUBL2Gh6wEwwOXfCnfhrt Pr6Ffx5bkNNZQHFHeRk08CzLwJn7dConjiFWyX3pIAStce3qLp2VRBqd3BAgiHSsimUb /VEePEOPq5s+Ahmf2j2PBZiMoU2X3nw4wtHBbi1qai+V7VQRRU5UlsvVpk2jI7Ca6XTQ oSGP/XXB5EW+UEXlKSs0xpA3JgTQBhnbCC6JiRKqS+acrHM0omdAbCQ7AiSlMOhV+ojV bVOyT0WUvZd9ky8KxaaTOrQ1lEGoiXoRNxiR8MtDo0KlPmff3DTn3MIFElAmfozCzIoe za0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706164240; x=1706769040; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=T7qF2ux/z3bZUzHUpWVLBPHatGr2T7HdgXLVBLlMyVI=; b=HX7XsgPjTS+QZIhdKYqrrAbuQqZ0rY8655ku9awDycwgrv2pupts7dn82wyFCFY+2z FTjiIasHR05JhS2QU28mP4IFvRSeEOolHyNDIcZERY2DgO108BVSOGb+ydlcnXE/1dni nI61op2rCE9Z5dFPnP78XbQOX3hRSKeLooW7ZOysTL1YB/RA9pOjuNaObjlYCCjiAcI/ DG0DZNjMc5SpsE9sokPRmH0QybsVn73rvnm+d+Linh4QtEY59j+ayZk+16l3TK4zUx3e 1am/coq/9MBFCzvZaxwUIu6TzH6epp9TTm8pYIpNCbg9HmJzKCISBzFaDjEyvNvw5snO iRcw== X-Gm-Message-State: AOJu0YzOV3h7ef3N33fPmxEFEUwRCNBuaBF0KmAsxTYyl2tcHqU5IMMr CC2j60AdQEkmioxnbzdmhNBWp/W6QtrlJ6N7PxL6ZPK0gpwpR9q3jyrGvK33C/w= X-Received: by 2002:a05:6a20:a929:b0:19b:5b08:1f4b with SMTP id cd41-20020a056a20a92900b0019b5b081f4bmr578106pzb.15.1706164239760; Wed, 24 Jan 2024 22:30:39 -0800 (PST) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id t19-20020a056a00139300b006dd870b51b8sm3201139pfg.126.2024.01.24.22.30.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jan 2024 22:30:39 -0800 (PST) From: debug@rivosinc.com To: rick.p.edgecombe@intel.com, broonie@kernel.org, Szabolcs.Nagy@arm.com, kito.cheng@sifive.com, keescook@chromium.org, ajones@ventanamicro.com, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, cleger@rivosinc.com, atishp@atishpatra.org, alex@ghiti.fr, bjorn@rivosinc.com, alexghiti@rivosinc.com Cc: corbet@lwn.net, aou@eecs.berkeley.edu, oleg@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, ebiederm@xmission.com, shuah@kernel.org, brauner@kernel.org, debug@rivosinc.com, guoren@kernel.org, samitolvanen@google.com, evan@rivosinc.com, xiao.w.wang@intel.com, apatel@ventanamicro.com, mchitale@ventanamicro.com, waylingii@gmail.com, greentime.hu@sifive.com, heiko@sntech.de, jszhang@kernel.org, shikemeng@huaweicloud.com, david@redhat.com, charlie@rivosinc.com, panqinglin2020@iscas.ac.cn, willy@infradead.org, vincent.chen@sifive.com, andy.chiu@sifive.com, gerg@kernel.org, jeeheng.sia@starfivetech.com, mason.huo@starfivetech.com, ancientmodern4@gmail.com, mathis.salmen@matsal.de, cuiyunhui@bytedance.com, bhe@redhat.com, chenjiahao16@huawei.com, ruscur@russell.cc, bgray@linux.ibm.com, alx@kernel.org, baruch@tkos.co.il, zhangqing@loongson.cn, catalin.marinas@arm.com, revest@chromium.org, josh@joshtriplett.org, joey.gouly@arm.com, shr@devkernel.io, omosnace@redhat.com, ojeda@kernel.org, jhubbard@nvidia.com, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [RFC PATCH v1 28/28] kselftest/riscv: kselftest for user mode cfi Date: Wed, 24 Jan 2024 22:21:53 -0800 Message-ID: <20240125062739.1339782-29-debug@rivosinc.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240125062739.1339782-1-debug@rivosinc.com> References: <20240125062739.1339782-1-debug@rivosinc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Deepak Gupta Adds kselftest for RISC-V control flow integrity implementation for user mode. There is not a lot going on in kernel for enabling landing pad for user mode. Thus kselftest simply enables landing pad for the binary and a signal handler is registered for SIGSEGV. Any control flow violation are reported as SIGSEGV with si_code = SEGV_CPERR. Test will fail on recieving any SEGV_CPERR. Shadow stack part has more changes in kernel and thus there are separate tests for that - enable and disable - Exercise `map_shadow_stack` syscall - `fork` test to make sure COW works for shadow stack pages - gup tests As of today kernel uses FOLL_FORCE when access happens to memory via /proc//mem. Not breaking that for shadow stack - signal test. Make sure signal delivery results in token creation on shadow stack and consumes (and verifies) token on sigreturn - shadow stack protection test. attempts to write using regular store instruction on shadow stack memory must result in access faults Signed-off-by: Deepak Gupta --- tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/cfi/Makefile | 10 + .../testing/selftests/riscv/cfi/cfi_rv_test.h | 85 ++++ .../selftests/riscv/cfi/riscv_cfi_test.c | 91 +++++ .../testing/selftests/riscv/cfi/shadowstack.c | 376 ++++++++++++++++++ .../testing/selftests/riscv/cfi/shadowstack.h | 39 ++ 6 files changed, 602 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/riscv/cfi/Makefile create mode 100644 tools/testing/selftests/riscv/cfi/cfi_rv_test.h create mode 100644 tools/testing/selftests/riscv/cfi/riscv_cfi_test.c create mode 100644 tools/testing/selftests/riscv/cfi/shadowstack.c create mode 100644 tools/testing/selftests/riscv/cfi/shadowstack.h diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 4a9ff515a3a0..867e5875b7ce 100644 --- a/tools/testing/selftests/riscv/Makefile +++ b/tools/testing/selftests/riscv/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),riscv)) -RISCV_SUBTARGETS ?= hwprobe vector mm +RISCV_SUBTARGETS ?= hwprobe vector mm cfi else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/cfi/Makefile b/tools/testing/selftests/riscv/cfi/Makefile new file mode 100644 index 000000000000..77f12157fa29 --- /dev/null +++ b/tools/testing/selftests/riscv/cfi/Makefile @@ -0,0 +1,10 @@ +CFLAGS += -I$(top_srcdir)/tools/include + +CFLAGS += -march=rv64gc_zicfilp_zicfiss + +TEST_GEN_PROGS := cfitests + +include ../../lib.mk + +$(OUTPUT)/cfitests: riscv_cfi_test.c shadowstack.c + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ diff --git a/tools/testing/selftests/riscv/cfi/cfi_rv_test.h b/tools/testing/selftests/riscv/cfi/cfi_rv_test.h new file mode 100644 index 000000000000..27267a2e1008 --- /dev/null +++ b/tools/testing/selftests/riscv/cfi/cfi_rv_test.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef SELFTEST_RISCV_CFI_H +#define SELFTEST_RISCV_CFI_H +#include +#include +#include "shadowstack.h" + +#define RISCV_CFI_SELFTEST_COUNT RISCV_SHADOW_STACK_TESTS + +#define CHILD_EXIT_CODE_SSWRITE 10 +#define CHILD_EXIT_CODE_SIG_TEST 11 + +#define BAD_POINTER (NULL) + +#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ +({ \ + register long _num __asm__ ("a7") = (num); \ + register long _arg1 __asm__ ("a0") = (long)(arg1); \ + register long _arg2 __asm__ ("a1") = (long)(arg2); \ + register long _arg3 __asm__ ("a2") = (long)(arg3); \ + register long _arg4 __asm__ ("a3") = (long)(arg4); \ + register long _arg5 __asm__ ("a4") = (long)(arg5); \ + \ + __asm__ volatile ( \ + "ecall\n" \ + : "+r"(_arg1) \ + : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ + "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + register long _num __asm__ ("a7") = (num); \ + register long _arg1 __asm__ ("a0") = (long)(arg1); \ + register long _arg2 __asm__ ("a1") = (long)(arg2); \ + register long _arg3 __asm__ ("a2") = (long)(arg3); \ + \ + __asm__ volatile ( \ + "ecall\n" \ + : "+r"(_arg1) \ + : "r"(_arg2), "r"(_arg3), \ + "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#ifndef __NR_prctl +#define __NR_prctl 167 +#endif + +#ifndef __NR_map_shadow_stack +#define __NR_map_shadow_stack 453 +#endif + +#define CSR_SSP 0x011 + +#ifdef __ASSEMBLY__ +#define __ASM_STR(x) x +#else +#define __ASM_STR(x) #x +#endif + +#define csr_read(csr) \ +({ \ + register unsigned long __v; \ + __asm__ __volatile__ ("csrr %0, " __ASM_STR(csr) \ + : "=r" (__v) : \ + : "memory"); \ + __v; \ +}) + +#define csr_write(csr, val) \ +({ \ + unsigned long __v = (unsigned long) (val); \ + __asm__ __volatile__ ("csrw " __ASM_STR(csr) ", %0" \ + : : "rK" (__v) \ + : "memory"); \ +}) + +#endif diff --git a/tools/testing/selftests/riscv/cfi/riscv_cfi_test.c b/tools/testing/selftests/riscv/cfi/riscv_cfi_test.c new file mode 100644 index 000000000000..c116ae4bb358 --- /dev/null +++ b/tools/testing/selftests/riscv/cfi/riscv_cfi_test.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "../../kselftest.h" +#include +#include +#include +#include "cfi_rv_test.h" + +/* do not optimize cfi related test functions */ +#pragma GCC push_options +#pragma GCC optimize("O0") + +#define SEGV_CPERR 10 /* control protection fault */ + +void sigsegv_handler(int signum, siginfo_t *si, void *uc) +{ + struct ucontext *ctx = (struct ucontext *) uc; + + if (si->si_code == SEGV_CPERR) { + printf("Control flow violation happened somewhere\n"); + printf("pc where violation happened %lx\n", ctx->uc_mcontext.gregs[0]); + exit(-1); + } + + /* null pointer deref */ + if (si->si_addr == BAD_POINTER) + exit(CHILD_EXIT_CODE_NULL_PTR_DEREF); + + /* shadow stack write case */ + exit(CHILD_EXIT_CODE_SSWRITE); +} + +int lpad_enable(void) +{ + int ret = 0; + + ret = my_syscall5(__NR_prctl, PR_SET_INDIR_BR_LP_STATUS, PR_INDIR_BR_LP_ENABLE, 0, 0, 0); + + return ret; +} + +bool register_signal_handler(void) +{ + struct sigaction sa = {}; + + sa.sa_sigaction = sigsegv_handler; + sa.sa_flags = SA_SIGINFO; + if (sigaction(SIGSEGV, &sa, NULL)) { + printf("registering signal handler for landing pad violation failed\n"); + return false; + } + + return true; +} + +int main(int argc, char *argv[]) +{ + int ret = 0; + unsigned long lpad_status = 0; + + ksft_print_header(); + + ksft_set_plan(RISCV_CFI_SELFTEST_COUNT); + + ksft_print_msg("starting risc-v tests\n"); + + /* + * Landing pad test. Not a lot of kernel changes to support landing + * pad for user mode except lighting up a bit in senvcfg via a prctl + * Enable landing pad through out the execution of test binary + */ + ret = my_syscall5(__NR_prctl, PR_GET_INDIR_BR_LP_STATUS, &lpad_status, 0, 0, 0); + if (ret) + ksft_exit_skip("Get landing pad status failed with %d\n", ret); + + ret = lpad_enable(); + + if (ret) + ksft_exit_skip("Enabling landing pad failed with %d\n", ret); + + if (!register_signal_handler()) + ksft_exit_skip("registering signal handler for SIGSEGV failed\n"); + + ksft_print_msg("landing pad enabled for binary\n"); + ksft_print_msg("starting risc-v shadow stack tests\n"); + execute_shadow_stack_tests(); + + ksft_finished(); +} + +#pragma GCC pop_options diff --git a/tools/testing/selftests/riscv/cfi/shadowstack.c b/tools/testing/selftests/riscv/cfi/shadowstack.c new file mode 100644 index 000000000000..126654801bed --- /dev/null +++ b/tools/testing/selftests/riscv/cfi/shadowstack.c @@ -0,0 +1,376 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "../../kselftest.h" +#include +#include +#include +#include +#include +#include "shadowstack.h" +#include "cfi_rv_test.h" + +/* do not optimize shadow stack related test functions */ +#pragma GCC push_options +#pragma GCC optimize("O0") + +void zar(void) +{ + unsigned long ssp = 0, swaped_val = 0; + + ssp = csr_read(CSR_SSP); + printf("inside %s and shadow stack ptr is %lx\n", __func__, ssp); +} + +void bar(void) +{ + printf("inside %s\n", __func__); + zar(); +} + +void foo(void) +{ + printf("inside %s\n", __func__); + bar(); +} + +void zar_child(void) +{ + unsigned long ssp = 0; + + ssp = csr_read(CSR_SSP); + printf("inside %s and shadow stack ptr is %lx\n", __func__, ssp); +} + +void bar_child(void) +{ + printf("inside %s\n", __func__); + zar_child(); +} + +void foo_child(void) +{ + printf("inside %s\n", __func__); + bar_child(); +} + +typedef void (call_func_ptr)(void); +/* + * call couple of functions to test push pop. + */ +int shadow_stack_call_tests(call_func_ptr fn_ptr, bool parent) +{ + if (parent) + printf("call test for parent\n"); + else + printf("call test for child\n"); + + (fn_ptr)(); + + return 0; +} + +bool enable_disable_check(unsigned long test_num, void *ctx) +{ + int ret = 0; + + if (!my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, PR_SHADOW_STACK_ENABLE, 0, 0, 0)) { + printf("Shadow stack was enabled\n"); + shadow_stack_call_tests(&foo, true); + + ret = my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, 0, 0, 0, 0); + if (ret) + ksft_test_result_fail("shadow stack disable failed\n"); + } else { + ksft_test_result_fail("shadow stack enable failed\n"); + ret = -EINVAL; + } + + return ret ? false : true; +} + +/* forks a thread, and ensure shadow stacks fork out */ +bool shadow_stack_fork_test(unsigned long test_num, void *ctx) +{ + int pid = 0, child_status = 0, parent_pid = 0; + + printf("exercising shadow stack fork test\n"); + + if (my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, PR_SHADOW_STACK_ENABLE, 0, 0, 0)) { + printf("shadow stack enable prctl failed\n"); + return false; + } + + parent_pid = getpid(); + pid = fork(); + + if (pid) { + printf("Parent pid %d and child pid %d\n", parent_pid, pid); + shadow_stack_call_tests(&foo, true); + } else + shadow_stack_call_tests(&foo_child, false); + + if (pid) { + printf("waiting on child to finish\n"); + wait(&child_status); + } else { + /* exit child gracefully */ + exit(0); + } + + if (pid && WIFSIGNALED(child_status)) { + printf("child faulted"); + return false; + } + + /* disable shadow stack again */ + if (my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, 0, 0, 0, 0)) { + printf("shadow stack disable prctl failed\n"); + return false; + } + + return true; +} + +/* exercise `map_shadow_stack`, pivot to it and call some functions to ensure it works */ +#define SHADOW_STACK_ALLOC_SIZE 4096 +bool shadow_stack_map_test(unsigned long test_num, void *ctx) +{ + unsigned long shdw_addr; + int ret = 0; + + shdw_addr = my_syscall3(__NR_map_shadow_stack, NULL, SHADOW_STACK_ALLOC_SIZE, 0); + + if (((long) shdw_addr) <= 0) { + printf("map_shadow_stack failed with error code %d\n", (int) shdw_addr); + return false; + } + + ret = munmap((void *) shdw_addr, SHADOW_STACK_ALLOC_SIZE); + + if (ret) { + printf("munmap failed with error code %d\n", ret); + return false; + } + + return true; +} + +/* + * shadow stack protection tests. map a shadow stack and + * validate all memory protections work on it + */ +bool shadow_stack_protection_test(unsigned long test_num, void *ctx) +{ + unsigned long shdw_addr; + unsigned long *write_addr = NULL; + int ret = 0, pid = 0, child_status = 0; + + shdw_addr = my_syscall3(__NR_map_shadow_stack, NULL, SHADOW_STACK_ALLOC_SIZE, 0); + + if (((long) shdw_addr) <= 0) { + printf("map_shadow_stack failed with error code %d\n", (int) shdw_addr); + return false; + } + + write_addr = (unsigned long *) shdw_addr; + pid = fork(); + + /* no child was created, return false */ + if (pid == -1) + return false; + + /* + * try to perform a store from child on shadow stack memory + * it should result in SIGSEGV + */ + if (!pid) { + /* below write must lead to SIGSEGV */ + *write_addr = 0xdeadbeef; + } else { + wait(&child_status); + } + + /* test fail, if 0xdeadbeef present on shadow stack address */ + if (*write_addr == 0xdeadbeef) { + printf("write suceeded\n"); + return false; + } + + /* if child reached here, then fail */ + if (!pid) { + printf("child reached unreachable state\n"); + return false; + } + + /* if child exited via signal handler but not for write on ss */ + if (WIFEXITED(child_status) && + WEXITSTATUS(child_status) != CHILD_EXIT_CODE_SSWRITE) { + printf("child wasn't signaled for write on shadow stack\n"); + return false; + } + + ret = munmap(write_addr, SHADOW_STACK_ALLOC_SIZE); + if (ret) { + printf("munmap failed with error code %d\n", ret); + return false; + } + + return true; +} + +#define SS_MAGIC_WRITE_VAL 0xbeefdead + +int gup_tests(int mem_fd, unsigned long *shdw_addr) +{ + unsigned long val = 0; + + lseek(mem_fd, (unsigned long)shdw_addr, SEEK_SET); + if (read(mem_fd, &val, sizeof(val)) < 0) { + printf("reading shadow stack mem via gup failed\n"); + return 1; + } + + val = SS_MAGIC_WRITE_VAL; + lseek(mem_fd, (unsigned long)shdw_addr, SEEK_SET); + if (write(mem_fd, &val, sizeof(val)) < 0) { + printf("writing shadow stack mem via gup failed\n"); + return 1; + } + + if (*shdw_addr != SS_MAGIC_WRITE_VAL) { + printf("GUP write to shadow stack memory didn't happen\n"); + return 1; + } + + return 0; +} + +bool shadow_stack_gup_tests(unsigned long test_num, void *ctx) +{ + unsigned long shdw_addr = 0; + unsigned long *write_addr = NULL; + int fd = 0; + bool ret = false; + + shdw_addr = my_syscall3(__NR_map_shadow_stack, NULL, SHADOW_STACK_ALLOC_SIZE, 0); + + if (((long) shdw_addr) <= 0) { + printf("map_shadow_stack failed with error code %d\n", (int) shdw_addr); + return false; + } + + write_addr = (unsigned long *) shdw_addr; + + fd = open("/proc/self/mem", O_RDWR); + if (fd == -1) + return false; + + if (gup_tests(fd, write_addr)) { + printf("gup tests failed\n"); + goto out; + } + + ret = true; +out: + if (shdw_addr && munmap(write_addr, SHADOW_STACK_ALLOC_SIZE)) { + printf("munmap failed with error code %d\n", ret); + ret = false; + } + + return ret; +} + +volatile bool break_loop; + +void sigusr1_handler(int signo) +{ + printf("In sigusr1 handler\n"); + break_loop = true; +} + +bool sigusr1_signal_test(void) +{ + if (signal(SIGUSR1, sigusr1_handler) == SIG_ERR) { + printf("registerting sigusr1 handler failed\n"); + return false; + } + + return true; +} +/* + * shadow stack signal test. shadow stack must be enabled. + * register a signal, fork another thread which is waiting + * on signal. Send a signal from parent to child, verify + * that signal was received by child. If not test fails + */ +bool shadow_stack_signal_test(unsigned long test_num, void *ctx) +{ + int pid = 0, child_status = 0; + unsigned long ssp = 0; + + if (my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, PR_SHADOW_STACK_ENABLE, 0, 0, 0)) { + printf("shadow stack enable prctl failed\n"); + return false; + } + + pid = fork(); + + if (pid == -1) { + printf("signal test: fork failed\n"); + goto out; + } + + if (pid == 0) { + /* this should be caught by signal handler and do an exit */ + if (!sigusr1_signal_test()) { + printf("sigusr1_signal_test failed\n"); + exit(-1); + } + + while (!break_loop) + sleep(1); + + exit(11); + /* child shouldn't go beyond here */ + } + /* send SIGUSR1 to child */ + kill(pid, SIGUSR1); + wait(&child_status); + +out: + if (my_syscall5(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, 0, 0, 0, 0)) { + printf("shadow stack disable prctl failed\n"); + return false; + } + + return (WIFEXITED(child_status) && + WEXITSTATUS(child_status) == 11); +} + +int execute_shadow_stack_tests(void) +{ + int ret = 0; + unsigned long test_count = 0; + unsigned long shstk_status = 0; + + printf("Executing RISC-V shadow stack self tests\n"); + + ret = my_syscall5(__NR_prctl, PR_GET_SHADOW_STACK_STATUS, &shstk_status, 0, 0, 0); + + if (ret != 0) + ksft_exit_skip("Get shadow stack status failed with %d\n", ret); + + /* + * If we are here that means get shadow stack status succeeded and + * thus shadow stack support is baked in the kernel. + */ + while (test_count < ARRAY_SIZE(shstk_tests)) { + ksft_test_result((*shstk_tests[test_count].t_func)(test_count, NULL), + shstk_tests[test_count].name); + test_count++; + } + + return 0; +} + +#pragma GCC pop_options diff --git a/tools/testing/selftests/riscv/cfi/shadowstack.h b/tools/testing/selftests/riscv/cfi/shadowstack.h new file mode 100644 index 000000000000..92cb0752238d --- /dev/null +++ b/tools/testing/selftests/riscv/cfi/shadowstack.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef SELFTEST_SHADOWSTACK_TEST_H +#define SELFTEST_SHADOWSTACK_TEST_H +#include +#include + +/* + * a cfi test returns true for success or false for fail + * takes a number for test number to index into array and void pointer. + */ +typedef bool (*shstk_test_func)(unsigned long test_num, void *); + +struct shadow_stack_tests { + char *name; + shstk_test_func t_func; +}; + +bool enable_disable_check(unsigned long test_num, void *ctx); +bool shadow_stack_fork_test(unsigned long test_num, void *ctx); +bool shadow_stack_map_test(unsigned long test_num, void *ctx); +bool shadow_stack_protection_test(unsigned long test_num, void *ctx); +bool shadow_stack_gup_tests(unsigned long test_num, void *ctx); +bool shadow_stack_signal_test(unsigned long test_num, void *ctx); + +static struct shadow_stack_tests shstk_tests[] = { + { "enable disable\n", enable_disable_check }, + { "shstk fork test\n", shadow_stack_fork_test }, + { "map shadow stack syscall\n", shadow_stack_map_test }, + { "shadow stack gup tests\n", shadow_stack_gup_tests }, + { "shadow stack signal tests\n", shadow_stack_signal_test}, + { "memory protections of shadow stack memory\n", shadow_stack_protection_test } +}; + +#define RISCV_SHADOW_STACK_TESTS ARRAY_SIZE(shstk_tests) + +int execute_shadow_stack_tests(void); + +#endif -- 2.43.0