tpm: introduce tpm_buf (a74f8b36) · Commits · 戴 / test

drivers/char/tpm/tpm.h

+97 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2004 IBM Corporation
		* Copyright (C) 2015 Intel Corporation
		*
		* Authors:
		* Leendert van Doorn <leendert@watson.ibm.com>
		@@ -28,6 +29,7 @@
		#include <linux/tpm.h>
		#include <linux/acpi.h>
		#include <linux/cdev.h>
		#include <linux/highmem.h>

		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;
		}

		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;

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