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 6D291C61DA4 for ; Sat, 18 Feb 2023 21:22:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230348AbjBRVWm (ORCPT ); Sat, 18 Feb 2023 16:22:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230224AbjBRVVm (ORCPT ); Sat, 18 Feb 2023 16:21:42 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 855291ABFA; Sat, 18 Feb 2023 13:19:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676755141; x=1708291141; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=rLqhRE2d5TzXO0jkrIimoFvYNyWSmS33HBbaA6qKIFg=; b=ldeR68weXIcb+J89Eq2jW5P7X2+SGIfjb32yverMoC48smSUv8D09qtK 5e8asO42UHfkSGP26LtgdXEEp49HQwpXWTEdrIK90sLF7n4PIq+4HW1Xa 4fGPx2ObWr/YpXNB9E/9S1NcjkJg/PfgRd3o7+r7ue7fz7SDBpm3bcF3O TxNnaNLFijoB8pL27ccttV5Uxuj27CdD8HMywqqU88RzvEPs2zlnH25Gz OCS2RO55i2hIbUzCE8v8ZZeGfMf0CWzXjtRmu34Bj/7ZLZ+KFj98XM1rc fEeuv2VmS1GhtUsi3KgduqWy1ObkQHlU27jNOcHtcv5wbOdPvsXDyYoE8 Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="418427849" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="418427849" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:25 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="664241739" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="664241739" Received: from adityava-mobl1.amr.corp.intel.com (HELO rpedgeco-desk.amr.corp.intel.com) ([10.209.80.223]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:24 -0800 From: Rick Edgecombe To: x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , Weijiang Yang , "Kirill A . Shutemov" , John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, akpm@linux-foundation.org, Andrew.Cooper3@citrix.com, christina.schimpe@intel.com, david@redhat.com, debug@rivosinc.com Cc: rick.p.edgecombe@intel.com Subject: [PATCH v6 35/41] x86: Expose thread features in /proc/$PID/status Date: Sat, 18 Feb 2023 13:14:27 -0800 Message-Id: <20230218211433.26859-36-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230218211433.26859-1-rick.p.edgecombe@intel.com> References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Applications and loaders can have logic to decide whether to enable shadow stack. They usually don't report whether shadow stack has been enabled or not, so there is no way to verify whether an application actually is protected by shadow stack. Add two lines in /proc/$PID/status to report enabled and locked features. Since, this involves referring to arch specific defines in asm/prctl.h, implement an arch breakout to emit the feature lines. Reviewed-by: Kees Cook Tested-by: Pengfei Xu Tested-by: John Allen Signed-off-by: Kirill A. Shutemov [Switched to CET, added to commit log] Signed-off-by: Rick Edgecombe --- v4: - Remove "CET" references v3: - Move to /proc/pid/status (Kees) v2: - New patch --- arch/x86/kernel/cpu/proc.c | 23 +++++++++++++++++++++++ fs/proc/array.c | 6 ++++++ include/linux/proc_fs.h | 2 ++ 3 files changed, 31 insertions(+) diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c index 099b6f0d96bd..31c0e68f6227 100644 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -4,6 +4,8 @@ #include #include #include +#include +#include #include "cpu.h" @@ -175,3 +177,24 @@ const struct seq_operations cpuinfo_op = { .stop = c_stop, .show = show_cpuinfo, }; + +#ifdef CONFIG_X86_USER_SHADOW_STACK +static void dump_x86_features(struct seq_file *m, unsigned long features) +{ + if (features & ARCH_SHSTK_SHSTK) + seq_puts(m, "shstk "); + if (features & ARCH_SHSTK_WRSS) + seq_puts(m, "wrss "); +} + +void arch_proc_pid_thread_features(struct seq_file *m, struct task_struct *task) +{ + seq_puts(m, "x86_Thread_features:\t"); + dump_x86_features(m, task->thread.features); + seq_putc(m, '\n'); + + seq_puts(m, "x86_Thread_features_locked:\t"); + dump_x86_features(m, task->thread.features_locked); + seq_putc(m, '\n'); +} +#endif /* CONFIG_X86_USER_SHADOW_STACK */ diff --git a/fs/proc/array.c b/fs/proc/array.c index 49283b8103c7..7ac43ecda1c2 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -428,6 +428,11 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm) seq_printf(m, "THP_enabled:\t%d\n", thp_enabled); } +__weak void arch_proc_pid_thread_features(struct seq_file *m, + struct task_struct *task) +{ +} + int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { @@ -451,6 +456,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, task_cpus_allowed(m, task); cpuset_task_status_allowed(m, task); task_context_switch_counts(m, task); + arch_proc_pid_thread_features(m, task); return 0; } diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 0260f5ea98fe..80ff8e533cbd 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -158,6 +158,8 @@ int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task); #endif /* CONFIG_PROC_PID_ARCH_STATUS */ +void arch_proc_pid_thread_features(struct seq_file *m, struct task_struct *task); + #else /* CONFIG_PROC_FS */ static inline void proc_root_init(void) -- 2.17.1