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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D634C46467 for ; Thu, 19 Jan 2023 18:05:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230173AbjASSFJ (ORCPT ); Thu, 19 Jan 2023 13:05:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjASSFG (ORCPT ); Thu, 19 Jan 2023 13:05:06 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 401B78B322 for ; Thu, 19 Jan 2023 10:04:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674151455; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+FQBlawSFh7WnrThFuQouGCxy+5V47LRQD3cnPHmpSo=; b=Xe9mi6mlbU6xrKsuAHgtM6gBulxrzcU913vin+amKRxkUUo/eOq5mImF++ECeAFPmlmzkF uNoNWKtspmWU5+Gz4As4VP6zHVGhSUOUHC+KDqIzPKQ1D4yDJVRbhWFO6FauTx9kHJaY4U 3kkSoYERAikSVDPgf/Ws/q6mA8R9/T0= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-490-bIs-pnYmOXanveZi3y7GGA-1; Thu, 19 Jan 2023 13:04:12 -0500 X-MC-Unique: bIs-pnYmOXanveZi3y7GGA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 285CA3C2274D; Thu, 19 Jan 2023 18:04:06 +0000 (UTC) Received: from localhost (unknown [10.39.195.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BFA88492B14; Thu, 19 Jan 2023 18:04:05 +0000 (UTC) From: Giuseppe Scrivano To: Brian Masney Cc: linux-kernel@vger.kernel.org, keescook@chromium.org, bristot@redhat.com, ebiederm@xmission.com, brauner@kernel.org, cyphar@cyphar.com, viro@zeniv.linux.org.uk, alexl@redhat.com, peterz@infradead.org Subject: Re: [PATCH v2 2/2] selftests: add tests for prctl(SET_HIDE_SELF_EXE) In-Reply-To: (Brian Masney's message of "Thu, 19 Jan 2023 12:44:07 -0500") References: <20230119170718.3129938-1-gscrivan@redhat.com> <20230119170718.3129938-2-gscrivan@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) Date: Thu, 19 Jan 2023 19:04:03 +0100 Message-ID: <87o7quflkc.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Brian Masney writes: > On Thu, Jan 19, 2023 at 06:07:18PM +0100, Giuseppe Scrivano wrote: >> Signed-off-by: Giuseppe Scrivano >> --- >> tools/testing/selftests/prctl/Makefile | 2 +- >> tools/testing/selftests/prctl/hide-self-exe.c | 101 ++++++++++++++++++ >> 2 files changed, 102 insertions(+), 1 deletion(-) >> create mode 100644 tools/testing/selftests/prctl/hide-self-exe.c >> >> diff --git a/tools/testing/selftests/prctl/Makefile b/tools/testing/selftests/prctl/Makefile >> index c7923b205222..024e107b26ec 100644 >> --- a/tools/testing/selftests/prctl/Makefile >> +++ b/tools/testing/selftests/prctl/Makefile >> @@ -5,7 +5,7 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/) >> >> ifeq ($(ARCH),x86) >> TEST_PROGS := disable-tsc-ctxt-sw-stress-test disable-tsc-on-off-stress-test \ >> - disable-tsc-test >> + disable-tsc-test hide-self-exe >> all: $(TEST_PROGS) >> >> include ../lib.mk >> diff --git a/tools/testing/selftests/prctl/hide-self-exe.c b/tools/testing/selftests/prctl/hide-self-exe.c >> new file mode 100644 >> index 000000000000..f86cef8e061c >> --- /dev/null >> +++ b/tools/testing/selftests/prctl/hide-self-exe.c >> @@ -0,0 +1,101 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Tests for prctl(PR_GET_HIDE_SELF_EXE, ...) / prctl(PR_SET_HIDE_SELF_EXE, ...) >> + * >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#include >> +#include >> + >> +#ifndef PR_SET_HIDE_SELF_EXE >> +# define PR_SET_HIDE_SELF_EXE 65 >> +# define PR_GET_HIDE_SELF_EXE 66 >> +#endif >> + >> +int main(void) >> +{ >> + int status; >> + pid_t pid; >> + int ret; >> + >> + ret = open("/proc/self/exe", O_RDONLY); >> + if (ret < 0) { >> + perror("open /proc/self/exe"); >> + exit(EXIT_FAILURE); >> + } >> + close(ret); >> + >> + ret = prctl(PR_GET_HIDE_SELF_EXE, 0, 0, 0, 0); >> + if (ret != 0) { >> + perror("prctl(PR_GET_HIDE_SELF_EXE)"); >> + exit(EXIT_FAILURE); >> + } >> + >> + ret = prctl(PR_SET_HIDE_SELF_EXE, 1, 0, 0, 0); >> + if (ret != 0) { >> + perror("prctl(PR_SET_HIDE_SELF_EXE)"); >> + exit(EXIT_FAILURE); >> + } >> + >> + /* check it doesn't fail a second time. */ >> + ret = prctl(PR_SET_HIDE_SELF_EXE, 1, 0, 0, 0); >> + if (ret != 0) { >> + perror("prctl(PR_SET_HIDE_SELF_EXE)"); >> + exit(EXIT_FAILURE); >> + } >> + >> + ret = prctl(PR_GET_HIDE_SELF_EXE, 0, 0, 0, 0); >> + if (ret != 1) { >> + perror("prctl(PR_GET_HIDE_SELF_EXE)"); >> + exit(EXIT_FAILURE); >> + } >> + >> + ret = open("/proc/self/exe", O_RDONLY); >> + if (ret >= 0 || errno != ENOENT) { >> + perror("open /proc/self/exe succeeded"); >> + exit(EXIT_FAILURE); >> + } >> + >> + pid = fork(); >> + if (pid < 0) { >> + perror("fork"); >> + exit(EXIT_FAILURE); >> + } >> + if (pid == 0) { >> + /* Verify that it is still unreachable after fork(). */ >> + ret = open("/proc/self/exe", O_RDONLY); >> + if (ret >= 0 || errno != ENOENT) >> + exit(EXIT_FAILURE); >> + close(ret); >> + >> + /* And that it cannot be unset. */ >> + ret = prctl(PR_GET_HIDE_SELF_EXE, 0, 0, 0, 0); > > Should this be PR_SET_HIDE_SELF_EXE? you are right, thanks for spotting it! I should test PR_SET_HIDE_SELF_EXE not the getter.