From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965106AbbJRDBi (ORCPT ); Sat, 17 Oct 2015 23:01:38 -0400 Received: from mout.gmx.net ([212.227.17.22]:61055 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932984AbbJRCvl (ORCPT ); Sat, 17 Oct 2015 22:51:41 -0400 From: Peter =?iso-8859-15?q?H=FCwe?= To: Jarkko Sakkinen Subject: Re: [PATCH 06/10] tpm: introduce tpm_buf Date: Sun, 18 Oct 2015 04:57:49 +0200 User-Agent: KMail/1.13.7 (Linux/4.2.3-dirty; KDE/4.14.8; x86_64; ; ) Cc: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jgunthorpe@obsidianresearch.com, dhowells@redhat.com, artem.bityutskiy@linux.intel.com, Marcel Selhorst References: <1445020843-9382-1-git-send-email-jarkko.sakkinen@linux.intel.com> <1445020843-9382-7-git-send-email-jarkko.sakkinen@linux.intel.com> In-Reply-To: <1445020843-9382-7-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201510180457.49277.PeterHuewe@gmx.de> X-Provags-ID: V03:K0:pJYybRgBrPFnOGf4ze9IRKm9SkCDhDvftPdXRJAzDZUSn4rYi8j PLjaTmqhIeoP/VODzPPMtUziOPo5DYX36ZHXu7ut23NqZ0XUJ36G3ta1hFwax7NzXUssK6h J64o/FpMKsH09cA7ZShObiIMaOZNc/RkhQauCmfvR4m2kY8U6o/mwUTw4/NvA9fTURurRqa hksfMdkYOq/AndhuMhAyA== X-UI-Out-Filterresults: notjunk:1;V01:K0:5f7ZWdzhcms=:7UzF+IEWYxapJPvM6BlPM0 iwFaPxVYBg+CVnj6UoOS5TmB1DVKSXTyp19h9qNFI84QnOzlK3pH/RT53s0DuI1Q+WVNGOFlO vnoQV2seIy+7KeTXusxjdg8F2aducoxZuzfcBN2C2WAlLp8qRLDTqevcU4vZN+BTFVh/Y7/AL NxLdnv4e4xVbAVvgxRGdD5f9RmRlrNJFDvSI2OjagytLc6/UQGkJZ/L7gauBb09kAO4Zl9DX6 RzXq6zCP5X29O2Z84I0bdneA5UdhrxuZVdwaIy9lKo1X9hJqsRmOzztCqQGO/rsw3tknqVk1a 2eqHXgBevQ9N+/4PNIUk2eqhmuycLRsesgrk38tzsSV2OTKKUsXAE4gzXpZ39ZVPu2MUHLM7q XxWMgI4ipGKZhCx4DYgJLZMX9bqRCLoWjJ2Ol5D6gyFvup834IFTzlA5vE6l40wGrWgjLXHLU nl7Uv5Sd9vgX+fO/yIPaEZ5/AflNLL+UN4x3sDIs80tx+5jCuASI5UeCBy014EeOsSuojq0qI fEfdmmwVDYe2DiWxugGIrG+iFud7mbIa1ys8m+mcf3u2p1W16HmVX+KXdYZPqLEFZb6+OGmns NGXhA1+6MTiQlGpusPtFxYtVBZbqRmH2ZrpEq27o1Zn7ROtJsdwxEdOpR8/mCTcnEbqBD5UyP iDn74ZMb4L/F26ZGNr49DUfsKPzzOYRyCG4CZ0KGtNOWVdeLS4YMpFtS1C/C0V2FZihtsVrr+ NUjix+ZLjn5VJqxHOTpnq69Qq7W43b46utFoKqmsLNCf9auQcWCNMTLSuT5o5UHIkPX2B87Zo rbBw4Ns Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, 16. Oktober 2015, 20:40:25 schrieb Jarkko Sakkinen: > This patch introduces struct tpm_buf that provides a string buffer for > constructing TPM commands. This allows to construct variable sized TPM > commands. For the buffer a page is allocated and mapped, which limits > maximum size to PAGE_SIZE. > > Variable sized TPM commands are needed in order to add algorithmic > agility. > > Signed-off-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm.h | 97 > ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 > insertions(+) > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 36ceb71..cb46f62 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -1,5 +1,6 @@ > /* > * Copyright (C) 2004 IBM Corporation > + * Copyright (C) 2015 Intel Corporation > * > * Authors: > * Leendert van Doorn > @@ -28,6 +29,7 @@ > #include > #include > #include > +#include > > enum tpm_const { > TPM_MINOR = 224, /* officially assigned */ > @@ -390,6 +392,101 @@ struct tpm_cmd_t { > tpm_cmd_params params; > } __packed; > > +/* A string buffer type for constructing TPM commands. This is based on > the + * ideas of string buffer code in security/keys/trusted.h but is heap > based + * in order to keep the stack usage minimal. > + */ > + > +enum tpm_buf_flags { > + TPM_BUF_OVERFLOW = BIT(0), > +}; > + > +struct tpm_buf { > + struct page *data_page; > + unsigned int flags; > + u8 *data; > +}; > + > +static inline void tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) > +{ > + struct tpm_input_header *head; > + > + buf->data_page = alloc_page(GFP_HIGHUSER); > + if (!buf->data_page) > + return -ENOMEM; > + > + buf->flags = 0; > + buf->data = kmap(buf->data_page); > + > + head = (struct tpm_input_header *) buf->data; > + > + head->tag = cpu_to_be16(tag); > + head->length = cpu_to_be32(sizeof(*head)); > + head->ordinal = cpu_to_be32(ordinal); > + > + return 0; > +} > + > +static inline void tpm_buf_destroy(struct tpm_buf *buf) > +{ > + kunmap(buf->data_page); > + __free_page(buf->data_page); > +} > + > +static inline u32 tpm_buf_length(struct tpm_buf *buf) > +{ > + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; > + > + return be32_to_cpu(head->length); > +} > + > +static inline u16 tpm_buf_tag(struct tpm_buf *buf) > +{ > + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; > + > + return be16_to_cpu(head->tag); > +} > + > +static inline void tpm_buf_append(struct tpm_buf *buf, > + const unsigned char *new_data, > + unsigned int new_len) > +{ > + struct tpm_input_header *head = (struct tpm_input_header *) buf->data; > + u32 len = tpm_buf_length(buf); > + > + /* Return silently if overflow has already happened. */ > + if (buf->flags & TPM_BUF_OVERFLOW) > + return; > + > + if ((len + new_len) > PAGE_SIZE) { > + WARN(1, "tpm_buf: overflow\n"); > + buf->flags |= TPM_BUF_OVERFLOW; > + return; > + } Why not use WARN_ONCE? > + > + memcpy(&buf->data[len], new_data, new_len); > + head->length = cpu_to_be32(len + new_len); > +} > + > +static inline void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value) > +{ > + tpm_buf_append(buf, &value, 1); > +} > + > +static inline void tpm_buf_append_u16(struct tpm_buf *buf, const u16 > value) +{ > + __be16 value2 = cpu_to_be16(value); > + > + tpm_buf_append(buf, (u8 *) &value2, 2); > +} > + > +static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 > value) +{ > + __be32 value2 = cpu_to_be32(value); > + > + tpm_buf_append(buf, (u8 *) &value2, 4); > +} > + > extern struct class *tpm_class; > extern dev_t tpm_devt; > extern const struct file_operations tpm_fops;