From patchwork Thu Aug 29 01:01:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Holland X-Patchwork-Id: 13782312 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 54AFEC71159 for ; Thu, 29 Aug 2024 01:02:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=h/aumojnQ/oIia25wTw2cCIq1C5EuY/+N3dzyN3lb/M=; b=qzf9oAQzmrY16h 3hdsMSb0M9tOznon0efH/G2d7eWl8uah++U5+OUQ7xBnC6ygAH0tx25O+q8cZnG/UX7/cMdJSKtfS bfZzQacMm0htl4QXskPCPdLbXADo6arDOVBnnGeEkDsl6su1TOlPeoYdrVZVXt1SmNXAQm19/13G/ /PC0FZh7+mfeD2bVD4Mr2UPW6zYzq/TEsPPYVrFtHjz5gBKlfNYdESfMzMf86L3zrc4h7051y5Fmx W/MkbdBJj7tCULYtB5/zE0amsLsCssIfp0d61fog2t9oWpEVEPtpi/8qgLUPiyxs44L4sx4BuzLg6 f4KwO0opgQnh83Z14IAA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjTYJ-000000003pI-1rJy; Thu, 29 Aug 2024 01:02:19 +0000 Received: from mail-pf1-x42a.google.com ([2607:f8b0:4864:20::42a]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjTY6-000000003ez-2aDI for linux-riscv@lists.infradead.org; Thu, 29 Aug 2024 01:02:09 +0000 Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-715cdc7a153so97755b3a.0 for ; Wed, 28 Aug 2024 18:02:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1724893326; x=1725498126; darn=lists.infradead.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=QdTr6WFexikZD5z5SMB0wNcwIFtpGfuIsUFT4S+mZyo=; b=LG/3axfglD9hvGLIg4E5wAuew//03kruKK7nOY57RM0OWJj3XZPhpahKtUvZ4R6ioz TjYq67D8T+VY6b06iGpVBHtqUhxDWL45miWBTwDfQg52sZkF7YlKonOskeETQH7zXR/P vyPz2+JdKmrDHsp24kfVULsvQbJFUCEo+VFpC2TyIm0q4za2YtLJway2I+x/EtfMZx5E uFx6y2UfNtKrlQTvFtrIwV/TcFjEjbFE4lIfAtqAhd3784MmMKondoNWqUOcywyLNSjj SMHBWJ46fmcpFVWOpLLmOzqPEJav81697dJsZn4z1g3EwEjg5fffJTDtAaJFaYrDHuwE C7Nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724893326; x=1725498126; 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=QdTr6WFexikZD5z5SMB0wNcwIFtpGfuIsUFT4S+mZyo=; b=dJNiQS21DYjCzk1daUYIudi8fOporki7bJpePwjBuwCV2yFNQ40MI3BGTRiNUs94dm TpFZqFPPEN3QYhstulsqO200qXrX2va4ThJvPBwiW5LL0gvKEYaJ8+nRPlq2HFA/S6vg jPMwbngrlyhKYffXjpgyFQt7yyyY/RgMJ/6/waNGEM+A59DYVtMvjVN5FQ95IqGsAIcu Wf98jGCZHsK200qf7KcUekXHl1Xvyhvr3FClmqeNUYHBN2QqraQFIHUNPpD1DHW73Uug vIkP6HatlB3vfM+uuFiPIRx7CdOinY2eEknQZUhMxPSrwIangv5p0SN3cH4v/biFjyMb rM+A== X-Forwarded-Encrypted: i=1; AJvYcCW38Gv+bAz50aIQ0F8ZcB51vHLTu6b0Oq+jxfVl7pYf05eBL7lOx2dKR6ukqvy1kYQLrOWRUM5WJA2MiQ==@lists.infradead.org X-Gm-Message-State: AOJu0YyQWWiq6U9TQdJ1AS1K9g1txNIcaZrR0zy3tn6+PDwbS7PV310e lXcDnQRgA2b4f+4QFXp2u6HUgVfObB6pJu+fl7NZZduzcHpBQemSFxZBswwdtlM= X-Google-Smtp-Source: AGHT+IFnyAUi+jdFWCp7P3UvK+iLjj8unoHUnQu+ZFU5AeGz5NMnrX1PmfJWm6s1iYa6KBrU206IDA== X-Received: by 2002:a05:6a00:3a99:b0:70e:ce95:b87 with SMTP id d2e1a72fcca58-715e0d94b8cmr1199293b3a.0.1724893325492; Wed, 28 Aug 2024 18:02:05 -0700 (PDT) Received: from sw06.internal.sifive.com ([4.53.31.132]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-715e5576a4dsm89670b3a.17.2024.08.28.18.02.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Aug 2024 18:02:05 -0700 (PDT) From: Samuel Holland To: Palmer Dabbelt , linux-riscv@lists.infradead.org Cc: devicetree@vger.kernel.org, Catalin Marinas , linux-kernel@vger.kernel.org, Anup Patel , Conor Dooley , kasan-dev@googlegroups.com, Atish Patra , Evgenii Stepanov , Krzysztof Kozlowski , Rob Herring , "Kirill A . Shutemov" , Samuel Holland Subject: [PATCH v4 07/10] selftests: riscv: Add a pointer masking test Date: Wed, 28 Aug 2024 18:01:29 -0700 Message-ID: <20240829010151.2813377-8-samuel.holland@sifive.com> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240829010151.2813377-1-samuel.holland@sifive.com> References: <20240829010151.2813377-1-samuel.holland@sifive.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240828_180206_722683_03999BA6 X-CRM114-Status: GOOD ( 23.83 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org This test covers the behavior of the PR_SET_TAGGED_ADDR_CTRL and PR_GET_TAGGED_ADDR_CTRL prctl() operations, their effects on the userspace ABI, and their effects on the system call ABI. Signed-off-by: Samuel Holland Reviewed-by: Charlie Jenkins Tested-by: Charlie Jenkins --- (no changes since v2) Changes in v2: - Rename "tags" directory to "pm" to avoid .gitignore rules - Add .gitignore file to ignore the compiled selftest binary - Write to a pipe to force dereferencing the user pointer - Handle SIGSEGV in the child process to reduce dmesg noise tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/pm/.gitignore | 1 + tools/testing/selftests/riscv/pm/Makefile | 10 + .../selftests/riscv/pm/pointer_masking.c | 330 ++++++++++++++++++ 4 files changed, 342 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/riscv/pm/.gitignore create mode 100644 tools/testing/selftests/riscv/pm/Makefile create mode 100644 tools/testing/selftests/riscv/pm/pointer_masking.c diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 7ce03d832b64..2ee1d1548c5f 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 $(ARCH),riscv)) -RISCV_SUBTARGETS ?= hwprobe vector mm sigreturn +RISCV_SUBTARGETS ?= hwprobe mm pm sigreturn vector else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/pm/.gitignore b/tools/testing/selftests/riscv/pm/.gitignore new file mode 100644 index 000000000000..b38358f91c4d --- /dev/null +++ b/tools/testing/selftests/riscv/pm/.gitignore @@ -0,0 +1 @@ +pointer_masking diff --git a/tools/testing/selftests/riscv/pm/Makefile b/tools/testing/selftests/riscv/pm/Makefile new file mode 100644 index 000000000000..ed82ff9c664e --- /dev/null +++ b/tools/testing/selftests/riscv/pm/Makefile @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0 + +CFLAGS += -I$(top_srcdir)/tools/include + +TEST_GEN_PROGS := pointer_masking + +include ../../lib.mk + +$(OUTPUT)/pointer_masking: pointer_masking.c + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ diff --git a/tools/testing/selftests/riscv/pm/pointer_masking.c b/tools/testing/selftests/riscv/pm/pointer_masking.c new file mode 100644 index 000000000000..0fe80f963ace --- /dev/null +++ b/tools/testing/selftests/riscv/pm/pointer_masking.c @@ -0,0 +1,330 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../../kselftest.h" + +#ifndef PR_PMLEN_SHIFT +#define PR_PMLEN_SHIFT 24 +#endif +#ifndef PR_PMLEN_MASK +#define PR_PMLEN_MASK (0x7fUL << PR_PMLEN_SHIFT) +#endif + +static int dev_zero; + +static int pipefd[2]; + +static sigjmp_buf jmpbuf; + +static void sigsegv_handler(int sig) +{ + siglongjmp(jmpbuf, 1); +} + +static int min_pmlen; +static int max_pmlen; + +static inline bool valid_pmlen(int pmlen) +{ + return pmlen == 0 || pmlen == 7 || pmlen == 16; +} + +static void test_pmlen(void) +{ + ksft_print_msg("Testing available PMLEN values\n"); + + for (int request = 0; request <= 16; request++) { + int pmlen, ret; + + ret = prctl(PR_SET_TAGGED_ADDR_CTRL, request << PR_PMLEN_SHIFT, 0, 0, 0); + if (ret) + goto pr_set_error; + + ret = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0); + ksft_test_result(ret >= 0, "PMLEN=%d PR_GET_TAGGED_ADDR_CTRL\n", request); + if (ret < 0) + goto pr_get_error; + + pmlen = (ret & PR_PMLEN_MASK) >> PR_PMLEN_SHIFT; + ksft_test_result(pmlen >= request, "PMLEN=%d constraint\n", request); + ksft_test_result(valid_pmlen(pmlen), "PMLEN=%d validity\n", request); + + if (min_pmlen == 0) + min_pmlen = pmlen; + if (max_pmlen < pmlen) + max_pmlen = pmlen; + + continue; + +pr_set_error: + ksft_test_result_skip("PMLEN=%d PR_GET_TAGGED_ADDR_CTRL\n", request); +pr_get_error: + ksft_test_result_skip("PMLEN=%d constraint\n", request); + ksft_test_result_skip("PMLEN=%d validity\n", request); + } + + if (max_pmlen == 0) + ksft_exit_fail_msg("Failed to enable pointer masking\n"); +} + +static int set_tagged_addr_ctrl(int pmlen, bool tagged_addr_abi) +{ + int arg, ret; + + arg = pmlen << PR_PMLEN_SHIFT | tagged_addr_abi; + ret = prctl(PR_SET_TAGGED_ADDR_CTRL, arg, 0, 0, 0); + if (!ret) { + ret = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0); + if (ret == arg) + return 0; + } + + return ret < 0 ? -errno : -ENODATA; +} + +static void test_dereference_pmlen(int pmlen) +{ + static volatile int i; + volatile int *p; + int ret; + + ret = set_tagged_addr_ctrl(pmlen, false); + if (ret) + return ksft_test_result_error("PMLEN=%d setup (%d)\n", pmlen, ret); + + i = pmlen; + + if (pmlen) { + p = (volatile int *)((uintptr_t)&i | 1UL << __riscv_xlen - pmlen); + + /* These dereferences should succeed. */ + if (sigsetjmp(jmpbuf, 1)) + return ksft_test_result_fail("PMLEN=%d valid tag\n", pmlen); + if (*p != pmlen) + return ksft_test_result_fail("PMLEN=%d bad value\n", pmlen); + *p++; + } + + p = (volatile int *)((uintptr_t)&i | 1UL << __riscv_xlen - pmlen - 1); + + /* These dereferences should raise SIGSEGV. */ + if (sigsetjmp(jmpbuf, 1)) + return ksft_test_result_pass("PMLEN=%d dereference\n", pmlen); + *p++; + ksft_test_result_fail("PMLEN=%d invalid tag\n", pmlen); +} + +static void test_dereference(void) +{ + ksft_print_msg("Testing userspace pointer dereference\n"); + + signal(SIGSEGV, sigsegv_handler); + + test_dereference_pmlen(0); + test_dereference_pmlen(min_pmlen); + test_dereference_pmlen(max_pmlen); + + signal(SIGSEGV, SIG_DFL); +} + +static void execve_child_sigsegv_handler(int sig) +{ + exit(42); +} + +static int execve_child(void) +{ + static volatile int i; + volatile int *p = (volatile int *)((uintptr_t)&i | 1UL << __riscv_xlen - 7); + + signal(SIGSEGV, execve_child_sigsegv_handler); + + /* This dereference should raise SIGSEGV. */ + return *p; +} + +static void test_fork_exec(void) +{ + int ret, status; + + ksft_print_msg("Testing fork/exec behavior\n"); + + ret = set_tagged_addr_ctrl(min_pmlen, false); + if (ret) + return ksft_test_result_error("setup (%d)\n", ret); + + if (fork()) { + wait(&status); + ksft_test_result(WIFEXITED(status) && WEXITSTATUS(status) == 42, + "dereference after fork\n"); + } else { + static volatile int i = 42; + volatile int *p = (volatile int *)((uintptr_t)&i | 1UL << __riscv_xlen - min_pmlen); + + /* This dereference should succeed. */ + exit(*p); + } + + if (fork()) { + wait(&status); + ksft_test_result(WIFEXITED(status) && WEXITSTATUS(status) == 42, + "dereference after fork+exec\n"); + } else { + /* Will call execve_child(). */ + execve("/proc/self/exe", (char *const []) { "", NULL }, NULL); + } +} + +static void test_tagged_addr_abi_sysctl(void) +{ + char value; + int fd; + + ksft_print_msg("Testing tagged address ABI sysctl\n"); + + fd = open("/proc/sys/abi/tagged_addr_disabled", O_WRONLY); + if (fd < 0) { + ksft_test_result_skip("failed to open sysctl file\n"); + ksft_test_result_skip("failed to open sysctl file\n"); + return; + } + + value = '1'; + pwrite(fd, &value, 1, 0); + ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == -EINVAL, + "sysctl disabled\n"); + + value = '0'; + pwrite(fd, &value, 1, 0); + ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == 0, + "sysctl enabled\n"); + + set_tagged_addr_ctrl(0, false); + + close(fd); +} + +static void test_tagged_addr_abi_pmlen(int pmlen) +{ + int i, *p, ret; + + i = ~pmlen; + + if (pmlen) { + p = (int *)((uintptr_t)&i | 1UL << __riscv_xlen - pmlen); + + ret = set_tagged_addr_ctrl(pmlen, false); + if (ret) + return ksft_test_result_error("PMLEN=%d ABI disabled setup (%d)\n", + pmlen, ret); + + ret = write(pipefd[1], p, sizeof(*p)); + if (ret >= 0 || errno != EFAULT) + return ksft_test_result_fail("PMLEN=%d ABI disabled write\n", pmlen); + + ret = read(dev_zero, p, sizeof(*p)); + if (ret >= 0 || errno != EFAULT) + return ksft_test_result_fail("PMLEN=%d ABI disabled read\n", pmlen); + + if (i != ~pmlen) + return ksft_test_result_fail("PMLEN=%d ABI disabled value\n", pmlen); + + ret = set_tagged_addr_ctrl(pmlen, true); + if (ret) + return ksft_test_result_error("PMLEN=%d ABI enabled setup (%d)\n", + pmlen, ret); + + ret = write(pipefd[1], p, sizeof(*p)); + if (ret != sizeof(*p)) + return ksft_test_result_fail("PMLEN=%d ABI enabled write\n", pmlen); + + ret = read(dev_zero, p, sizeof(*p)); + if (ret != sizeof(*p)) + return ksft_test_result_fail("PMLEN=%d ABI enabled read\n", pmlen); + + if (i) + return ksft_test_result_fail("PMLEN=%d ABI enabled value\n", pmlen); + + i = ~pmlen; + } else { + /* The tagged address ABI cannot be enabled when PMLEN == 0. */ + ret = set_tagged_addr_ctrl(pmlen, true); + if (ret != -EINVAL) + return ksft_test_result_error("PMLEN=%d ABI setup (%d)\n", + pmlen, ret); + } + + p = (int *)((uintptr_t)&i | 1UL << __riscv_xlen - pmlen - 1); + + ret = write(pipefd[1], p, sizeof(*p)); + if (ret >= 0 || errno != EFAULT) + return ksft_test_result_fail("PMLEN=%d invalid tag write (%d)\n", pmlen, errno); + + ret = read(dev_zero, p, sizeof(*p)); + if (ret >= 0 || errno != EFAULT) + return ksft_test_result_fail("PMLEN=%d invalid tag read\n", pmlen); + + if (i != ~pmlen) + return ksft_test_result_fail("PMLEN=%d invalid tag value\n", pmlen); + + ksft_test_result_pass("PMLEN=%d tagged address ABI\n", pmlen); +} + +static void test_tagged_addr_abi(void) +{ + ksft_print_msg("Testing tagged address ABI\n"); + + test_tagged_addr_abi_pmlen(0); + test_tagged_addr_abi_pmlen(min_pmlen); + test_tagged_addr_abi_pmlen(max_pmlen); +} + +static struct test_info { + unsigned int nr_tests; + void (*test_fn)(void); +} tests[] = { + { .nr_tests = 17 * 3, test_pmlen }, + { .nr_tests = 3, test_dereference }, + { .nr_tests = 2, test_fork_exec }, + { .nr_tests = 2, test_tagged_addr_abi_sysctl }, + { .nr_tests = 3, test_tagged_addr_abi }, +}; + +int main(int argc, char **argv) +{ + unsigned int plan = 0; + int ret; + + /* Check if this is the child process after execve(). */ + if (!argv[0][0]) + return execve_child(); + + dev_zero = open("/dev/zero", O_RDWR); + if (dev_zero < 0) + return 1; + + /* Write to a pipe so the kernel must dereference the buffer pointer. */ + ret = pipe(pipefd); + if (ret) + return 1; + + ksft_print_header(); + + for (int i = 0; i < ARRAY_SIZE(tests); ++i) + plan += tests[i].nr_tests; + + ksft_set_plan(plan); + + for (int i = 0; i < ARRAY_SIZE(tests); ++i) + tests[i].test_fn(); + + ksft_finished(); +}