2016-11-23 10:12:57

by Winkler, Tomas

[permalink] [raw]
Subject: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on
all platforms for unaligned access.

The fix doesn't cover all the cases as also some cast
structures have members on unaligned addresses.

Signed-off-by: Tomas Winkler <[email protected]>
---
drivers/char/tpm/tpm-interface.c | 4 ++--
drivers/char/tpm/tpm-sysfs.c | 2 +-
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm_crb.c | 4 ++--
drivers/char/tpm/tpm_i2c_infineon.c | 5 +++--
drivers/char/tpm/tpm_i2c_nuvoton.c | 7 ++++---
drivers/char/tpm/tpm_nsc.c | 4 +---
drivers/char/tpm/tpm_tis_core.c | 4 ++--
8 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 769d8b0d31a3..4cf38d00d1b3 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
if (bufsiz > TPM_BUFSIZE)
bufsiz = TPM_BUFSIZE;

- count = be32_to_cpu(*((__be32 *) (buf + 2)));
- ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+ count = get_unaligned_be32(buf + 2);
+ ordinal = get_unaligned_be32(buf + 6);
if (count == 0)
return -ENODATA;
if (count > bufsiz) {
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 848ad6580b46..2435d710b6af 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -71,7 +71,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
data[12], data[13], data[14], data[15],
data[16], data[17], data[18], data[19],
data[20], data[21], data[22], data[23],
- be32_to_cpu(*((__be32 *) (data + 24))));
+ be32_to_cpup((__be32 *)(data + 24)));

for (i = 0; i < 256; i++) {
str += sprintf(str, "%02X ", data[i + 28]);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 1ae976894257..83dba0ff5ea0 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -23,6 +23,7 @@
#ifndef __TPM_H__
#define __TPM_H__

+#include <asm/unaligned.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/fs.h>
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 65040d74bb02..8067cfbfdbe2 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -168,7 +168,7 @@ static u8 crb_status(struct tpm_chip *chip)
static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
- unsigned int expected;
+ u32 expected;

/* sanity check */
if (count < 6)
@@ -178,7 +178,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
return -EIO;

memcpy_fromio(buf, priv->rsp, 6);
- expected = be32_to_cpup((__be32 *) &buf[2]);
+ expected = get_unaligned_be32(buf + 2);

if (expected > count)
return -EIO;
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
index 62ee44e57ddc..2dd4e3bb14c7 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -437,7 +437,8 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
int size = 0;
- int expected, status;
+ u32 expected;
+ int status;

if (count < TPM_HEADER_SIZE) {
size = -EIO;
@@ -451,7 +452,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
goto out;
}

- expected = be32_to_cpu(*(__be32 *)(buf + 2));
+ expected = get_unaligned_be32(buf + 2);
if ((size_t) expected > count) {
size = -EIO;
goto out;
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index e3a9155ee671..7ba9c435da4e 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -273,7 +273,8 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
struct device *dev = chip->dev.parent;
struct i2c_client *client = to_i2c_client(dev);
s32 rc;
- int expected, status, burst_count, retries, size = 0;
+ int status, burst_count, retries, size = 0;
+ u32 expected;

if (count < TPM_HEADER_SIZE) {
i2c_nuvoton_ready(chip); /* return to idle */
@@ -314,7 +315,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
* convert number of expected bytes field from big endian 32 bit
* to machine native
*/
- expected = be32_to_cpu(*(__be32 *) (buf + 2));
+ expected = get_unaligned_be32(buf + 2);
if (expected > count) {
dev_err(dev, "%s() expected > count\n", __func__);
size = -EIO;
@@ -442,7 +443,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
i2c_nuvoton_ready(chip);
return rc;
}
- ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+ ordinal = get_unaligned_be32(buf + 6);
rc = i2c_nuvoton_wait_for_data_avail(chip,
tpm_calc_ordinal_duration(chip,
ordinal),
diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 9ff0e072c476..99a8ff6ea37d 100644
--- a/drivers/char/tpm/tpm_nsc.c
+++ b/drivers/char/tpm/tpm_nsc.c
@@ -131,7 +131,6 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
u8 *buffer = buf;
u8 data, *p;
u32 size;
- __be32 *native_size;

if (count < 6)
return -EIO;
@@ -174,8 +173,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
return -EIO;
}

- native_size = (__force __be32 *) (buf + 2);
- size = be32_to_cpu(*native_size);
+ size = get_unaligned_be32(buf + 2);

if (count < size)
return -EIO;
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 7993678954a2..5323c54dc917 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -222,7 +222,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
goto out;
}

- expected = be32_to_cpu(*(__be32 *) (buf + 2));
+ expected = get_unaligned_be32(buf + 2);
if (expected > count) {
size = -EIO;
goto out;
@@ -371,7 +371,7 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
goto out_err;

if (chip->flags & TPM_CHIP_FLAG_IRQ) {
- ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+ ordinal = get_unaligned_be32(buf + 6);

if (chip->flags & TPM_CHIP_FLAG_TPM2)
dur = tpm2_calc_ordinal_duration(chip, ordinal);
--
2.7.4


2016-11-23 16:57:44

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote:
> Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on
> all platforms for unaligned access.
>
> The fix doesn't cover all the cases as also some cast
> structures have members on unaligned addresses.

I think this is a good idea..

> @@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> if (bufsiz > TPM_BUFSIZE)
> bufsiz = TPM_BUFSIZE;
>
> - count = be32_to_cpu(*((__be32 *) (buf + 2)));
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + count = get_unaligned_be32(buf + 2);
> + ordinal = get_unaligned_be32(buf + 6);

But lets fix this better and get rid of the constants too...

const tpm_input_header *hdr = buf;
count = be32_to_cpu(hdr->length);
ordinal = be32_to_cpu(hdr->ordinal);

Compiler will take care of unaligned for __packed.

> @@ -178,7 +178,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> return -EIO;
>
> memcpy_fromio(buf, priv->rsp, 6);
> - expected = be32_to_cpup((__be32 *) &buf[2]);
> + expected = get_unaligned_be32(buf + 2);

Here too, except tpm_output_header (and is tpm1 and 2 the same here?)

> @@ -451,7 +452,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> goto out;
> }
>
> - expected = be32_to_cpu(*(__be32 *)(buf + 2));
> + expected = get_unaligned_be32(buf + 2);

Ditto

> @@ -314,7 +315,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> * convert number of expected bytes field from big endian 32 bit
> * to machine native
> */
> - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> + expected = get_unaligned_be32(buf + 2);

Ditto

> if (expected > count) {
> dev_err(dev, "%s() expected > count\n", __func__);
> size = -EIO;
> @@ -442,7 +443,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
> i2c_nuvoton_ready(chip);
> return rc;
> }
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + ordinal = get_unaligned_be32(buf + 6);

Ditto

> @@ -174,8 +173,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
> return -EIO;
> }
>
> - native_size = (__force __be32 *) (buf + 2);
> - size = be32_to_cpu(*native_size);
> + size = get_unaligned_be32(buf + 2);

Ditto

> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 7993678954a2..5323c54dc917 100644
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -222,7 +222,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> goto out;
> }
>
> - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> + expected = get_unaligned_be32(buf + 2);

Ditto

> @@ -371,7 +371,7 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
> goto out_err;
>
> if (chip->flags & TPM_CHIP_FLAG_IRQ) {
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + ordinal = get_unaligned_be32(buf + 6);

Ditto

Jason

2016-11-23 20:56:36

by Winkler, Tomas

[permalink] [raw]
Subject: RE: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

> On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote:
> > Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on all
> > platforms for unaligned access.
> >
> > The fix doesn't cover all the cases as also some cast structures have
> > members on unaligned addresses.
>
> I think this is a good idea..
>
> > @@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8
> *buf, size_t bufsiz,
> > if (bufsiz > TPM_BUFSIZE)
> > bufsiz = TPM_BUFSIZE;
> >
> > - count = be32_to_cpu(*((__be32 *) (buf + 2)));
> > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> > + count = get_unaligned_be32(buf + 2);
> > + ordinal = get_unaligned_be32(buf + 6);
>
> But lets fix this better and get rid of the constants too...

> const tpm_input_header *hdr = buf;
> count = be32_to_cpu(hdr->length);
> ordinal = be32_to_cpu(hdr->ordinal);
>
> Compiler will take care of unaligned for __packed.

Yes, compiler takes care at performance penalty but probably we don't care about that much,
and readability is maybe more important here. What I've done is pretty much mechanical fix,
I agree this is better approach in this particular case.

> > @@ -178,7 +178,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf,
> size_t count)
> > return -EIO;
> >
> > memcpy_fromio(buf, priv->rsp, 6);
> > - expected = be32_to_cpup((__be32 *) &buf[2]);
> > + expected = get_unaligned_be32(buf + 2);
>
> Here too, except tpm_output_header (and is tpm1 and 2 the same here?)
>
> > @@ -451,7 +452,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8
> *buf, size_t count)
> > goto out;
> > }
> >
> > - expected = be32_to_cpu(*(__be32 *)(buf + 2));
> > + expected = get_unaligned_be32(buf + 2);
>
> Ditto
>
> > @@ -314,7 +315,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8
> *buf, size_t count)
> > * convert number of expected bytes field from big endian 32
> bit
> > * to machine native
> > */
> > - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> > + expected = get_unaligned_be32(buf + 2);
>
> Ditto
>
> > if (expected > count) {
> > dev_err(dev, "%s() expected > count\n", __func__);
> > size = -EIO;
> > @@ -442,7 +443,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8
> *buf, size_t len)
> > i2c_nuvoton_ready(chip);
> > return rc;
> > }
> > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> > + ordinal = get_unaligned_be32(buf + 6);
>
> Ditto
>
> > @@ -174,8 +173,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 *
> buf, size_t count)
> > return -EIO;
> > }
> >
> > - native_size = (__force __be32 *) (buf + 2);
> > - size = be32_to_cpu(*native_size);
> > + size = get_unaligned_be32(buf + 2);
>
> Ditto
>
> > diff --git a/drivers/char/tpm/tpm_tis_core.c
> > b/drivers/char/tpm/tpm_tis_core.c index 7993678954a2..5323c54dc917
> > 100644
> > +++ b/drivers/char/tpm/tpm_tis_core.c
> > @@ -222,7 +222,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8
> *buf, size_t count)
> > goto out;
> > }
> >
> > - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> > + expected = get_unaligned_be32(buf + 2);
>
> Ditto
>
> > @@ -371,7 +371,7 @@ static int tpm_tis_send_main(struct tpm_chip *chip,
> u8 *buf, size_t len)
> > goto out_err;
> >
> > if (chip->flags & TPM_CHIP_FLAG_IRQ) {
> > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> > + ordinal = get_unaligned_be32(buf + 6);
>
> Ditto
>
> Jason

2016-11-23 21:02:24

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

On Wed, Nov 23, 2016 at 08:56:25PM +0000, Winkler, Tomas wrote:
> > On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote:
> > > Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on all
> > > platforms for unaligned access.
> > >
> > > The fix doesn't cover all the cases as also some cast structures have
> > > members on unaligned addresses.
> >
> > I think this is a good idea..
> >
> > > @@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8
> > *buf, size_t bufsiz,
> > > if (bufsiz > TPM_BUFSIZE)
> > > bufsiz = TPM_BUFSIZE;
> > >
> > > - count = be32_to_cpu(*((__be32 *) (buf + 2)));
> > > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> > > + count = get_unaligned_be32(buf + 2);
> > > + ordinal = get_unaligned_be32(buf + 6);
> >
> > But lets fix this better and get rid of the constants too...
>
> > const tpm_input_header *hdr = buf;
> > count = be32_to_cpu(hdr->length);
> > ordinal = be32_to_cpu(hdr->ordinal);
> >
> > Compiler will take care of unaligned for __packed.
>
> Yes, compiler takes care at performance penalty but probably we
> don't care about that much,

Hmm? get_unaligned_be32 boils down to the same __packed construct.

As is today we must be hitting the in-kernel unaligned access trap (eg
on ARM) which is *very* expensive so this is a very worthwhile fix ...

Jason

2016-11-24 13:34:06

by Jarkko Sakkinen

[permalink] [raw]
Subject: Re: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote:
> Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on
> all platforms for unaligned access.
>
> The fix doesn't cover all the cases as also some cast
> structures have members on unaligned addresses.
>
> Signed-off-by: Tomas Winkler <[email protected]>

This looks good to me with the exceptio that was pointed out by Jason.
CC the next version to the linux-security-module. I talked with James
about this at LPC and since this list does not have too many active
reviewers it makes sense to cycle all the non-trivial changes through
that list.

/Jarkko

> ---
> drivers/char/tpm/tpm-interface.c | 4 ++--
> drivers/char/tpm/tpm-sysfs.c | 2 +-
> drivers/char/tpm/tpm.h | 1 +
> drivers/char/tpm/tpm_crb.c | 4 ++--
> drivers/char/tpm/tpm_i2c_infineon.c | 5 +++--
> drivers/char/tpm/tpm_i2c_nuvoton.c | 7 ++++---
> drivers/char/tpm/tpm_nsc.c | 4 +---
> drivers/char/tpm/tpm_tis_core.c | 4 ++--
> 8 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 769d8b0d31a3..4cf38d00d1b3 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
> if (bufsiz > TPM_BUFSIZE)
> bufsiz = TPM_BUFSIZE;
>
> - count = be32_to_cpu(*((__be32 *) (buf + 2)));
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + count = get_unaligned_be32(buf + 2);
> + ordinal = get_unaligned_be32(buf + 6);
> if (count == 0)
> return -ENODATA;
> if (count > bufsiz) {
> diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
> index 848ad6580b46..2435d710b6af 100644
> --- a/drivers/char/tpm/tpm-sysfs.c
> +++ b/drivers/char/tpm/tpm-sysfs.c
> @@ -71,7 +71,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
> data[12], data[13], data[14], data[15],
> data[16], data[17], data[18], data[19],
> data[20], data[21], data[22], data[23],
> - be32_to_cpu(*((__be32 *) (data + 24))));
> + be32_to_cpup((__be32 *)(data + 24)));
>
> for (i = 0; i < 256; i++) {
> str += sprintf(str, "%02X ", data[i + 28]);
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 1ae976894257..83dba0ff5ea0 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -23,6 +23,7 @@
> #ifndef __TPM_H__
> #define __TPM_H__
>
> +#include <asm/unaligned.h>
> #include <linux/module.h>
> #include <linux/delay.h>
> #include <linux/fs.h>
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 65040d74bb02..8067cfbfdbe2 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -168,7 +168,7 @@ static u8 crb_status(struct tpm_chip *chip)
> static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> {
> struct crb_priv *priv = dev_get_drvdata(&chip->dev);
> - unsigned int expected;
> + u32 expected;
>
> /* sanity check */
> if (count < 6)
> @@ -178,7 +178,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> return -EIO;
>
> memcpy_fromio(buf, priv->rsp, 6);
> - expected = be32_to_cpup((__be32 *) &buf[2]);
> + expected = get_unaligned_be32(buf + 2);
>
> if (expected > count)
> return -EIO;
> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
> index 62ee44e57ddc..2dd4e3bb14c7 100644
> --- a/drivers/char/tpm/tpm_i2c_infineon.c
> +++ b/drivers/char/tpm/tpm_i2c_infineon.c
> @@ -437,7 +437,8 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
> static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> {
> int size = 0;
> - int expected, status;
> + u32 expected;
> + int status;
>
> if (count < TPM_HEADER_SIZE) {
> size = -EIO;
> @@ -451,7 +452,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> goto out;
> }
>
> - expected = be32_to_cpu(*(__be32 *)(buf + 2));
> + expected = get_unaligned_be32(buf + 2);
> if ((size_t) expected > count) {
> size = -EIO;
> goto out;
> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> index e3a9155ee671..7ba9c435da4e 100644
> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> @@ -273,7 +273,8 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> struct device *dev = chip->dev.parent;
> struct i2c_client *client = to_i2c_client(dev);
> s32 rc;
> - int expected, status, burst_count, retries, size = 0;
> + int status, burst_count, retries, size = 0;
> + u32 expected;
>
> if (count < TPM_HEADER_SIZE) {
> i2c_nuvoton_ready(chip); /* return to idle */
> @@ -314,7 +315,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> * convert number of expected bytes field from big endian 32 bit
> * to machine native
> */
> - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> + expected = get_unaligned_be32(buf + 2);
> if (expected > count) {
> dev_err(dev, "%s() expected > count\n", __func__);
> size = -EIO;
> @@ -442,7 +443,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
> i2c_nuvoton_ready(chip);
> return rc;
> }
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + ordinal = get_unaligned_be32(buf + 6);
> rc = i2c_nuvoton_wait_for_data_avail(chip,
> tpm_calc_ordinal_duration(chip,
> ordinal),
> diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
> index 9ff0e072c476..99a8ff6ea37d 100644
> --- a/drivers/char/tpm/tpm_nsc.c
> +++ b/drivers/char/tpm/tpm_nsc.c
> @@ -131,7 +131,6 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
> u8 *buffer = buf;
> u8 data, *p;
> u32 size;
> - __be32 *native_size;
>
> if (count < 6)
> return -EIO;
> @@ -174,8 +173,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
> return -EIO;
> }
>
> - native_size = (__force __be32 *) (buf + 2);
> - size = be32_to_cpu(*native_size);
> + size = get_unaligned_be32(buf + 2);
>
> if (count < size)
> return -EIO;
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 7993678954a2..5323c54dc917 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -222,7 +222,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> goto out;
> }
>
> - expected = be32_to_cpu(*(__be32 *) (buf + 2));
> + expected = get_unaligned_be32(buf + 2);
> if (expected > count) {
> size = -EIO;
> goto out;
> @@ -371,7 +371,7 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
> goto out_err;
>
> if (chip->flags & TPM_CHIP_FLAG_IRQ) {
> - ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
> + ordinal = get_unaligned_be32(buf + 6);
>
> if (chip->flags & TPM_CHIP_FLAG_TPM2)
> dur = tpm2_calc_ordinal_duration(chip, ordinal);
> --
> 2.7.4
>

2016-12-03 15:30:41

by Jarkko Sakkinen

[permalink] [raw]
Subject: Re: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access.

Hey,

On Thu, Nov 24, 2016 at 03:34:00PM +0200, Jarkko Sakkinen wrote:
> On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote:
> > Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on
> > all platforms for unaligned access.
> >
> > The fix doesn't cover all the cases as also some cast
> > structures have members on unaligned addresses.
> >
> > Signed-off-by: Tomas Winkler <[email protected]>
>
> This looks good to me with the exceptio that was pointed out by Jason.
> CC the next version to the linux-security-module. I talked with James
> about this at LPC and since this list does not have too many active
> reviewers it makes sense to cycle all the non-trivial changes through
> that list.

Are you planning to send an updated version of this. Should be a
no-brainer to apply.

/Jarkko