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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9113EC4321E for ; Mon, 10 Sep 2018 19:33:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 587482086E for ; Mon, 10 Sep 2018 19:33:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 587482086E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728874AbeIKA3A (ORCPT ); Mon, 10 Sep 2018 20:29:00 -0400 Received: from mga04.intel.com ([192.55.52.120]:65105 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727742AbeIKA3A (ORCPT ); Mon, 10 Sep 2018 20:29:00 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Sep 2018 12:33:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,356,1531810800"; d="scan'208";a="73137890" Received: from sai-dev-mach.sc.intel.com ([143.183.140.52]) by orsmga006.jf.intel.com with ESMTP; 10 Sep 2018 12:33:21 -0700 From: Sai Praneeth Prakhya To: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Cc: Sai Praneeth , Al Stone , Borislav Petkov , Ingo Molnar , Andy Lutomirski , Bhupesh Sharma , Thomas Gleixner , Peter Zijlstra , Ard Biesheuvel Subject: [PATCH V5 1/2] efi: Make efi_rts_work accessible to efi page fault handler Date: Mon, 10 Sep 2018 12:32:24 -0700 Message-Id: <1536607945-22018-2-git-send-email-sai.praneeth.prakhya@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536607945-22018-1-git-send-email-sai.praneeth.prakhya@intel.com> References: <1536607945-22018-1-git-send-email-sai.praneeth.prakhya@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sai Praneeth After the kernel has booted, if any accesses by firmware causes a page fault, the efi page fault handler would freeze efi_rts_wq and schedules a new process. To do this, the efi page fault handler needs efi_rts_work. Hence, make it accessible. There will be no race conditions in accessing this structure, because, all the calls to efi runtime services are already serialized. Tested-by: Bhupesh Sharma Suggested-by: Matt Fleming Based-on-code-from: Ricardo Neri Signed-off-by: Sai Praneeth Prakhya Cc: Al Stone Cc: Borislav Petkov Cc: Ingo Molnar Cc: Andy Lutomirski Cc: Bhupesh Sharma Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Ard Biesheuvel --- drivers/firmware/efi/runtime-wrappers.c | 53 ++++++--------------------------- include/linux/efi.h | 36 ++++++++++++++++++++++ 2 files changed, 45 insertions(+), 44 deletions(-) diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index aa66cbf23512..b18b2d864c2c 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -45,39 +45,7 @@ #define __efi_call_virt(f, args...) \ __efi_call_virt_pointer(efi.systab->runtime, f, args) -/* efi_runtime_service() function identifiers */ -enum efi_rts_ids { - GET_TIME, - SET_TIME, - GET_WAKEUP_TIME, - SET_WAKEUP_TIME, - GET_VARIABLE, - GET_NEXT_VARIABLE, - SET_VARIABLE, - QUERY_VARIABLE_INFO, - GET_NEXT_HIGH_MONO_COUNT, - UPDATE_CAPSULE, - QUERY_CAPSULE_CAPS, -}; - -/* - * efi_runtime_work: Details of EFI Runtime Service work - * @arg<1-5>: EFI Runtime Service function arguments - * @status: Status of executing EFI Runtime Service - * @efi_rts_id: EFI Runtime Service function identifier - * @efi_rts_comp: Struct used for handling completions - */ -struct efi_runtime_work { - void *arg1; - void *arg2; - void *arg3; - void *arg4; - void *arg5; - efi_status_t status; - struct work_struct work; - enum efi_rts_ids efi_rts_id; - struct completion efi_rts_comp; -}; +struct efi_runtime_work efi_rts_work; /* * efi_queue_work: Queue efi_runtime_service() and wait until it's done @@ -91,7 +59,6 @@ struct efi_runtime_work { */ #define efi_queue_work(_rts, _arg1, _arg2, _arg3, _arg4, _arg5) \ ({ \ - struct efi_runtime_work efi_rts_work; \ efi_rts_work.status = EFI_ABORTED; \ \ init_completion(&efi_rts_work.efi_rts_comp); \ @@ -184,18 +151,16 @@ static DEFINE_SEMAPHORE(efi_runtime_lock); */ static void efi_call_rts(struct work_struct *work) { - struct efi_runtime_work *efi_rts_work; void *arg1, *arg2, *arg3, *arg4, *arg5; efi_status_t status = EFI_NOT_FOUND; - efi_rts_work = container_of(work, struct efi_runtime_work, work); - arg1 = efi_rts_work->arg1; - arg2 = efi_rts_work->arg2; - arg3 = efi_rts_work->arg3; - arg4 = efi_rts_work->arg4; - arg5 = efi_rts_work->arg5; + arg1 = efi_rts_work.arg1; + arg2 = efi_rts_work.arg2; + arg3 = efi_rts_work.arg3; + arg4 = efi_rts_work.arg4; + arg5 = efi_rts_work.arg5; - switch (efi_rts_work->efi_rts_id) { + switch (efi_rts_work.efi_rts_id) { case GET_TIME: status = efi_call_virt(get_time, (efi_time_t *)arg1, (efi_time_cap_t *)arg2); @@ -253,8 +218,8 @@ static void efi_call_rts(struct work_struct *work) */ pr_err("Requested executing invalid EFI Runtime Service.\n"); } - efi_rts_work->status = status; - complete(&efi_rts_work->efi_rts_comp); + efi_rts_work.status = status; + complete(&efi_rts_work.efi_rts_comp); } static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) diff --git a/include/linux/efi.h b/include/linux/efi.h index 401e4b254e30..855992b15269 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1659,7 +1659,43 @@ struct linux_efi_tpm_eventlog { extern int efi_tpm_eventlog_init(void); +/* efi_runtime_service() function identifiers */ +enum efi_rts_ids { + GET_TIME, + SET_TIME, + GET_WAKEUP_TIME, + SET_WAKEUP_TIME, + GET_VARIABLE, + GET_NEXT_VARIABLE, + SET_VARIABLE, + QUERY_VARIABLE_INFO, + GET_NEXT_HIGH_MONO_COUNT, + UPDATE_CAPSULE, + QUERY_CAPSULE_CAPS, +}; + +/* + * efi_runtime_work: Details of EFI Runtime Service work + * @arg<1-5>: EFI Runtime Service function arguments + * @status: Status of executing EFI Runtime Service + * @efi_rts_id: EFI Runtime Service function identifier + * @efi_rts_comp: Struct used for handling completions + */ +struct efi_runtime_work { + void *arg1; + void *arg2; + void *arg3; + void *arg4; + void *arg5; + efi_status_t status; + struct work_struct work; + enum efi_rts_ids efi_rts_id; + struct completion efi_rts_comp; +}; + /* Workqueue to queue EFI Runtime Services */ extern struct workqueue_struct *efi_rts_wq; +extern struct efi_runtime_work efi_rts_work; + #endif /* _LINUX_EFI_H */ -- 2.7.4