diff mbox series

[02/12] tpm: move buffer handling from static inlines to real functions

Message ID 20230216201410.15010-3-James.Bottomley@HansenPartnership.com (mailing list archive)
State New
Headers show
Series add integrity and security to TPM2 transactions | expand

Commit Message

James Bottomley Feb. 16, 2023, 8:14 p.m. UTC 
separate out the tpm_buf_... handling functions from static inlines in
tpm.h and move them to their own tpm-buf.c file.  This is a precursor
to adding new functions for other TPM type handling because the amount
of code will grow from the current 70 lines in tpm.h to about 200
lines when the additions are done.  200 lines of inline functions is a
bit too much to keep in a header file.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---
v3: make tpm_buf_tag static
---
 drivers/char/tpm/Makefile  |  1 +
 drivers/char/tpm/tpm-buf.c | 95 ++++++++++++++++++++++++++++++++++++++
 include/linux/tpm.h        | 86 ++++------------------------------
 3 files changed, 105 insertions(+), 77 deletions(-)
 create mode 100644 drivers/char/tpm/tpm-buf.c

Comments

Jarkko Sakkinen Feb. 27, 2023, 8:18 a.m. UTC | #1 
On Thu, Feb 16, 2023 at 03:14:00PM -0500, James Bottomley wrote:
> separate out the tpm_buf_... handling functions from static inlines in
> tpm.h and move them to their own tpm-buf.c file.  This is a precursor
> to adding new functions for other TPM type handling because the amount
> of code will grow from the current 70 lines in tpm.h to about 200
> lines when the additions are done.  200 lines of inline functions is a
> bit too much to keep in a header file.
> 
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> 
> ---
> v3: make tpm_buf_tag static
> ---
>  drivers/char/tpm/Makefile  |  1 +
>  drivers/char/tpm/tpm-buf.c | 95 ++++++++++++++++++++++++++++++++++++++
>  include/linux/tpm.h        | 86 ++++------------------------------
>  3 files changed, 105 insertions(+), 77 deletions(-)
>  create mode 100644 drivers/char/tpm/tpm-buf.c
> 
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index 0222b1ddb310..ad3594e383e1 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -15,6 +15,7 @@ tpm-y += tpm-sysfs.o
>  tpm-y += eventlog/common.o
>  tpm-y += eventlog/tpm1.o
>  tpm-y += eventlog/tpm2.o
> +tpm-y += tpm-buf.o
>  
>  tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o
>  tpm-$(CONFIG_EFI) += eventlog/efi.o
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> new file mode 100644
> index 000000000000..ca59b92e0f95
> --- /dev/null
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0
> +

This empty line should be removed.

> +/*
> + * Handing for tpm_buf structures to facilitate the building of commands
> + */
> +
> +#include <linux/module.h>
> +#include <linux/tpm.h>
> +

Now that symbols are compiled and also exported, it would be good to add
also kdoc's while at it, e.g.

/*
 * tpm_buf_init - Init a buffer for a TPM command
 * @buf:        uninitialized buffer
 * @tag:        tag of a TPM command
 * @ordinal:    number of a TPM command
 *
 * Allocate a page sized buffer from heap for a TPM command, and initialize
 * the command header.
 */

It is probably better to have an additional patch for this, as this one
should just move code around.

> +int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
> +{
> +	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> +	if (!buf->data)
> +		return -ENOMEM;
> +
> +	buf->flags = 0;
> +	tpm_buf_reset(buf, tag, ordinal);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_init);
> +
> +void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)

Ditto.

I guess you can fill these out. I just put an example to give a rough
idea what to put.

> +{
> +	struct tpm_header *head = (struct tpm_header *) buf->data;
> +
> +	head->tag = cpu_to_be16(tag);
> +	head->length = cpu_to_be32(sizeof(*head));
> +	head->ordinal = cpu_to_be32(ordinal);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_reset);
> +
> +void tpm_buf_destroy(struct tpm_buf *buf)

Ditto.

> +{
> +	free_page((unsigned long)buf->data);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_destroy);
> +
> +u32 tpm_buf_length(struct tpm_buf *buf)

Ditto.

> +{
> +	struct tpm_header *head = (struct tpm_header *)buf->data;
> +
> +	return be32_to_cpu(head->length);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_length);
> +
> +static u16 tpm_buf_tag(struct tpm_buf *buf)

Ditto.

> +{
> +	struct tpm_header *head = (struct tpm_header *)buf->data;
> +
> +	return be16_to_cpu(head->tag);
> +}
> +
> +void tpm_buf_append(struct tpm_buf *buf,
> +		    const unsigned char *new_data,
> +		    unsigned int new_len)
> +{
> +	struct tpm_header *head = (struct tpm_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);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_append);
> +
> +void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value)

Ditto.

> +{
> +	tpm_buf_append(buf, &value, 1);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_append_u8);
> +
> +void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value)

Ditto.

> +{
> +	__be16 value2 = cpu_to_be16(value);
> +
> +	tpm_buf_append(buf, (u8 *) &value2, 2);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_append_u16);
> +
> +void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value)

Ditto.

> +{
> +	__be32 value2 = cpu_to_be32(value);
> +
> +	tpm_buf_append(buf, (u8 *) &value2, 4);
> +}
> +EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index dfeb25a0362d..150b39b6190e 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -322,84 +322,16 @@ struct tpm2_hash {
>  	unsigned int tpm_id;
>  };
>  
> -static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
> -{
> -	struct tpm_header *head = (struct tpm_header *)buf->data;
> -
> -	head->tag = cpu_to_be16(tag);
> -	head->length = cpu_to_be32(sizeof(*head));
> -	head->ordinal = cpu_to_be32(ordinal);
> -}
> -
> -static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
> -{
> -	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> -	if (!buf->data)
> -		return -ENOMEM;
> -
> -	buf->flags = 0;
> -	tpm_buf_reset(buf, tag, ordinal);
> -	return 0;
> -}
> -
> -static inline void tpm_buf_destroy(struct tpm_buf *buf)
> -{
> -	free_page((unsigned long)buf->data);
> -}
> -
> -static inline u32 tpm_buf_length(struct tpm_buf *buf)
> -{
> -	struct tpm_header *head = (struct tpm_header *)buf->data;
> -
> -	return be32_to_cpu(head->length);
> -}
> -
> -static inline u16 tpm_buf_tag(struct tpm_buf *buf)
> -{
> -	struct tpm_header *head = (struct tpm_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_header *head = (struct tpm_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);
> -}
> +int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);
> +void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);
> +void tpm_buf_destroy(struct tpm_buf *buf);
> +u32 tpm_buf_length(struct tpm_buf *buf);
> +void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data,
> +		    unsigned int new_len);
> +void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value);
> +void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value);
> +void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value);
>  
>  /*
>   * Check if TPM device is in the firmware upgrade mode.
> -- 
> 2.35.3
> 

Since you are now moving things around, I think we should make best of it.

I'd consider a subsequent patch after this to further clean up the flow:

struct tpm_buf *tpm_buf_init(u16 tag, u32 ordinal)
{
        struct tpm_buf *buf;

        buf = kzalloc(sizeof(*buf), GFP_KERNEL);
        if (!buf)
                goto err_alloc_buf;

	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
	if (!buf->data)
                goto err_alloc_page;

	buf->flags = 0;
	tpm_buf_reset(buf, tag, ordinal);

	return 0;
        
err_alloc_page:
        kfree(buf);

err_alloc_buf:
        return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL_GPL(tpm_buf_init);

void tpm_buf_destroy(struct tpm_buf *buf)
{
	free_page((unsigned long)buf->data);
        kfree(buf);
}

There is 28 call sites for tpm_buf_init() buf the change is
fairly trival as tpm_buf_destroy() calls can stay as they are.

BR, Jarkko
diff mbox series

Patch

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 0222b1ddb310..ad3594e383e1 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -15,6 +15,7 @@  tpm-y += tpm-sysfs.o
 tpm-y += eventlog/common.o
 tpm-y += eventlog/tpm1.o
 tpm-y += eventlog/tpm2.o
+tpm-y += tpm-buf.o
 
 tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o
 tpm-$(CONFIG_EFI) += eventlog/efi.o
diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
new file mode 100644
index 000000000000..ca59b92e0f95
--- /dev/null
+++ b/drivers/char/tpm/tpm-buf.c
@@ -0,0 +1,95 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Handing for tpm_buf structures to facilitate the building of commands
+ */
+
+#include <linux/module.h>
+#include <linux/tpm.h>
+
+int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
+{
+	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
+	if (!buf->data)
+		return -ENOMEM;
+
+	buf->flags = 0;
+	tpm_buf_reset(buf, tag, ordinal);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_buf_init);
+
+void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
+{
+	struct tpm_header *head = (struct tpm_header *) buf->data;
+
+	head->tag = cpu_to_be16(tag);
+	head->length = cpu_to_be32(sizeof(*head));
+	head->ordinal = cpu_to_be32(ordinal);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_reset);
+
+void tpm_buf_destroy(struct tpm_buf *buf)
+{
+	free_page((unsigned long)buf->data);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_destroy);
+
+u32 tpm_buf_length(struct tpm_buf *buf)
+{
+	struct tpm_header *head = (struct tpm_header *)buf->data;
+
+	return be32_to_cpu(head->length);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_length);
+
+static u16 tpm_buf_tag(struct tpm_buf *buf)
+{
+	struct tpm_header *head = (struct tpm_header *)buf->data;
+
+	return be16_to_cpu(head->tag);
+}
+
+void tpm_buf_append(struct tpm_buf *buf,
+		    const unsigned char *new_data,
+		    unsigned int new_len)
+{
+	struct tpm_header *head = (struct tpm_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);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_append);
+
+void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value)
+{
+	tpm_buf_append(buf, &value, 1);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_append_u8);
+
+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);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_append_u16);
+
+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);
+}
+EXPORT_SYMBOL_GPL(tpm_buf_append_u32);
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index dfeb25a0362d..150b39b6190e 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -322,84 +322,16 @@  struct tpm2_hash {
 	unsigned int tpm_id;
 };
 
-static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
-{
-	struct tpm_header *head = (struct tpm_header *)buf->data;
-
-	head->tag = cpu_to_be16(tag);
-	head->length = cpu_to_be32(sizeof(*head));
-	head->ordinal = cpu_to_be32(ordinal);
-}
-
-static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
-{
-	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
-	if (!buf->data)
-		return -ENOMEM;
-
-	buf->flags = 0;
-	tpm_buf_reset(buf, tag, ordinal);
-	return 0;
-}
-
-static inline void tpm_buf_destroy(struct tpm_buf *buf)
-{
-	free_page((unsigned long)buf->data);
-}
-
-static inline u32 tpm_buf_length(struct tpm_buf *buf)
-{
-	struct tpm_header *head = (struct tpm_header *)buf->data;
-
-	return be32_to_cpu(head->length);
-}
-
-static inline u16 tpm_buf_tag(struct tpm_buf *buf)
-{
-	struct tpm_header *head = (struct tpm_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_header *head = (struct tpm_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);
-}
+int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);
+void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);
+void tpm_buf_destroy(struct tpm_buf *buf);
+u32 tpm_buf_length(struct tpm_buf *buf);
+void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data,
+		    unsigned int new_len);
+void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value);
+void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value);
+void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value);
 
 /*
  * Check if TPM device is in the firmware upgrade mode.