From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 007E0C432C3 for ; Sat, 16 Nov 2019 11:51:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB4DD20723 for ; Sat, 16 Nov 2019 11:51:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727550AbfKPLv1 (ORCPT ); Sat, 16 Nov 2019 06:51:27 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:45231 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727471AbfKPLv1 (ORCPT ); Sat, 16 Nov 2019 06:51:27 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iVwbq-00026G-BP; Sat, 16 Nov 2019 12:51:22 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 0D3B71C1901; Sat, 16 Nov 2019 12:51:22 +0100 (CET) Date: Sat, 16 Nov 2019 11:51:21 -0000 From: "tip-bot2 for Thomas Gleixner" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/iopl] selftests/x86/iopl: Extend test to cover IOPL emulation Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <157390508200.12247.14682981591292814407.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/iopl branch of tip: Commit-ID: e638ad00809a323cbe13dfa0952d4234d9b36732 Gitweb: https://git.kernel.org/tip/e638ad00809a323cbe13dfa0952d4234d9b36732 Author: Thomas Gleixner AuthorDate: Mon, 11 Nov 2019 23:03:30 +01:00 Committer: Thomas Gleixner CommitterDate: Sat, 16 Nov 2019 11:24:06 +01:00 selftests/x86/iopl: Extend test to cover IOPL emulation Add tests that the now emulated iopl() functionality: - does not longer allow user space to disable interrupts. - does restore a I/O bitmap when IOPL is dropped Signed-off-by: Thomas Gleixner --- tools/testing/selftests/x86/iopl.c | 129 +++++++++++++++++++++++++--- 1 file changed, 118 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/x86/iopl.c b/tools/testing/selftests/x86/iopl.c index 6aa27f3..bab2f6e 100644 --- a/tools/testing/selftests/x86/iopl.c +++ b/tools/testing/selftests/x86/iopl.c @@ -35,6 +35,16 @@ static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), } +static void clearhandler(int sig) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + static jmp_buf jmpbuf; static void sigsegv(int sig, siginfo_t *si, void *ctx_void) @@ -42,25 +52,128 @@ static void sigsegv(int sig, siginfo_t *si, void *ctx_void) siglongjmp(jmpbuf, 1); } +static bool try_outb(unsigned short port) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("outb %%al, %w[port]" + : : [port] "Nd" (port), "a" (0)); + return true; + } + clearhandler(SIGSEGV); +} + +static void expect_ok_outb(unsigned short port) +{ + if (!try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx failed\n", port); + exit(1); + } + + printf("[OK]\toutb to 0x%02hx worked\n", port); +} + +static void expect_gp_outb(unsigned short port) +{ + if (try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx worked\n", port); + nerrs++; + } + + printf("[OK]\toutb to 0x%02hx failed\n", port); +} + +static bool try_cli(void) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("cli"); + return true; + } + clearhandler(SIGSEGV); +} + +static bool try_sti(void) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("sti"); + return true; + } + clearhandler(SIGSEGV); +} + +static void expect_gp_sti(void) +{ + if (try_sti()) { + printf("[FAIL]\tSTI worked\n"); + nerrs++; + } else { + printf("[OK]\tSTI faulted\n"); + } +} + +static void expect_gp_cli(void) +{ + if (try_cli()) { + printf("[FAIL]\tCLI worked\n"); + nerrs++; + } else { + printf("[OK]\tCLI faulted\n"); + } +} + int main(void) { cpu_set_t cpuset; + CPU_ZERO(&cpuset); CPU_SET(0, &cpuset); if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) err(1, "sched_setaffinity to CPU 0"); /* Probe for iopl support. Note that iopl(0) works even as nonroot. */ - if (iopl(3) != 0) { + switch(iopl(3)) { + case 0: + break; + case -ENOSYS: + printf("[OK]\tiopl() nor supported\n"); + return 0; + default: printf("[OK]\tiopl(3) failed (%d) -- try running as root\n", errno); return 0; } - /* Restore our original state prior to starting the test. */ + /* Make sure that CLI/STI are blocked even with IOPL level 3 */ + expect_gp_cli(); + expect_gp_sti(); + expect_ok_outb(0x80); + + /* Establish an I/O bitmap to test the restore */ + if (ioperm(0x80, 1, 1) != 0) + err(1, "ioperm(0x80, 1, 1) failed\n"); + + /* Restore our original state prior to starting the fork test. */ if (iopl(0) != 0) err(1, "iopl(0)"); + /* + * Verify that IOPL emulation is disabled and the I/O bitmap still + * works. + */ + expect_ok_outb(0x80); + expect_gp_outb(0xed); + /* Drop the I/O bitmap */ + if (ioperm(0x80, 1, 0) != 0) + err(1, "ioperm(0x80, 1, 0) failed\n"); + pid_t child = fork(); if (child == -1) err(1, "fork"); @@ -90,14 +203,9 @@ int main(void) printf("[RUN]\tparent: write to 0x80 (should fail)\n"); - sethandler(SIGSEGV, sigsegv, 0); - if (sigsetjmp(jmpbuf, 1) != 0) { - printf("[OK]\twrite was denied\n"); - } else { - asm volatile ("outb %%al, $0x80" : : "a" (0)); - printf("[FAIL]\twrite was allowed\n"); - nerrs++; - } + expect_gp_outb(0x80); + expect_gp_cli(); + expect_gp_sti(); /* Test the capability checks. */ printf("\tiopl(3)\n"); @@ -133,4 +241,3 @@ int main(void) done: return nerrs ? 1 : 0; } -