Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756861Ab2HJHXX (ORCPT ); Fri, 10 Aug 2012 03:23:23 -0400 Received: from ozlabs.org ([203.10.76.45]:55178 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755643Ab2HJHXU (ORCPT ); Fri, 10 Aug 2012 03:23:20 -0400 Message-ID: <1344583401.27290.15.camel@concordia> Subject: Re: [PATCH V2 3/3] drivers/char/tpm: Add securityfs support for event log From: Michael Ellerman To: Ashley Lai Cc: linux-kernel@vger.kernel.org, rcj@linux.vnet.ibm.com, linux-security-module@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, adlai@us.ibm.com, key@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Date: Fri, 10 Aug 2012 17:23:21 +1000 In-Reply-To: <1344553986.28791.13.camel@footlong> References: <1344553253.28791.7.camel@footlong> <1344553986.28791.13.camel@footlong> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5227 Lines: 188 On Thu, 2012-08-09 at 18:13 -0500, Ashley Lai wrote: > This patch retrieves the event log data from the device tree > during file open. The event log data will then displayed through > securityfs. Hi Ashley, Comments inline .. > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile > index 547509d..b53da57 100644 > --- a/drivers/char/tpm/Makefile > +++ b/drivers/char/tpm/Makefile > @@ -2,9 +2,15 @@ > # Makefile for the kernel tpm device drivers. > # > obj-$(CONFIG_TCG_TPM) += tpm.o > +obj-$(CONFIG_TCG_TPM) += tpm_bios.o > ifdef CONFIG_ACPI > - obj-$(CONFIG_TCG_TPM) += tpm_bios.o > tpm_bios-objs += tpm_eventlog.o tpm_acpi.o > +else > +ifdef CONFIG_TCG_IBMVTPM > + tpm_bios-objs += tpm_eventlog.o tpm_of.o > +else > + tpm_bios-objs += tpm_eventlog.o tpm_noeventlog.o What does it mean to build tpm_eventlog and tpm_noeventlog ? > diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h > index 8e23ccd..21ac6af 100644 > --- a/drivers/char/tpm/tpm_eventlog.h > +++ b/drivers/char/tpm/tpm_eventlog.h > @@ -68,4 +68,18 @@ enum tcpa_pc_event_ids { > }; > > int read_log(struct tpm_bios_log *log); > + > +extern struct dentry **tpm_bios_log_setup(char *); > +extern void tpm_bios_log_teardown(struct dentry **); > + > +#ifdef CONFIG_PPC64 > +#define TPM_NO_EVENT_LOG !of_find_node_by_name(NULL, "ibm,vtpm") > +#else > +#ifdef CONFIG_ACPI > +#define TPM_NO_EVENT_LOG 0 > +#else > +#define TPM_NO_EVENT_LOG 1 > +#endif > +#endif This should be a static inline, with the ifdefs inside. How often is this called? of_find_node_by_name() is not particularly efficient. It might be better to search once and save a flag indicating whether you found it. Also you must call of_node_put() on the result of of_find_node_by_name(), so at the least you must do: struct device_node *np; np = of_find_node_by_name(NULL, "ibm,vtpm"); of_node_put(np); return (np != NULL); > #endif > diff --git a/drivers/char/tpm/tpm_noeventlog.c b/drivers/char/tpm/tpm_noeventlog.c > new file mode 100644 > index 0000000..f30a2bf > --- /dev/null > +++ b/drivers/char/tpm/tpm_noeventlog.c > @@ -0,0 +1,21 @@ > +/* > + * Copyright (C) 2012 IBM Corporation ^^ Don't use (C) > + * > + * Author: Ashley Lai > + * > + * Maintained by: > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * as published by the Free Software Foundation; either version > + * 2 of the License, or (at your option) any later version. > + * > + */ > + > +#include > +#include "tpm_eventlog.h" > + > +int read_log(struct tpm_bios_log *log) > +{ > + return -EINVAL; > +} Wouldn't it be simpler to put this in a header with the appropriate ifdefs, and then you'd need less logic in the Makefile? > diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c > new file mode 100644 > index 0000000..6d44adb > --- /dev/null > +++ b/drivers/char/tpm/tpm_of.c > @@ -0,0 +1,68 @@ > +/* > + * Copyright 2012 IBM Corporation > + * > + * Author: Ashley Lai > + * > + * Maintained by: > + * > + * Read the event log created by the firmware on PPC64 > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * as published by the Free Software Foundation; either version > + * 2 of the License, or (at your option) any later version. > + * > + */ > + > +#include > +#include > + > +#include "tpm.h" > +#include "tpm_eventlog.h" > + > +int read_log(struct tpm_bios_log *log) > +{ > + struct device_node *np; > + const u32 *sizep; > + const __be64 *basep; > + > + if (log->bios_event_log != NULL) { > + pr_err("%s: ERROR - Eventlog already initialized\n", __func__); > + return -EFAULT; > + } > + > + np = of_find_node_by_name(NULL, "ibm,vtpm"); > + if (!np) { > + pr_err("%s: ERROR - IBMVTPM not supported\n", __func__); > + return -ENODEV; > + } All your return paths below here must call of_node_put(np). > + sizep = of_get_property(np, "linux,sml-size", NULL); > + if (sizep == NULL) { > + pr_err("%s: ERROR - SML size not found\n", __func__); > + return -EIO; > + } > + if (*sizep == 0) { > + pr_err("%s: ERROR - event log area empty\n", __func__); > + return -EIO; > + } > + > + basep = of_get_property(np, "linux,sml-base", NULL); > + if (basep == NULL) { > + pr_err(KERN_ERR "%s: ERROR - SML not found\n", __func__); > + return -EIO; > + } > + > + log->bios_event_log = kmalloc(*sizep, GFP_KERNEL); > + if (!log->bios_event_log) { > + pr_err("%s: ERROR - Not enough memory for BIOS measurements\n", > + __func__); > + return -ENOMEM; > + } > + > + log->bios_event_log_end = log->bios_event_log + *sizep; > + > + memcpy(log->bios_event_log, __va(be64_to_cpup(basep)), *sizep); > + > + return 0; > +} cheers -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/