| Message ID | 20210914151032.216122-2-amirmizi6@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add tpm i2c ptp driver | expand |
On Tue, 2021-09-14 at 18:10 +0300, amirmizi6@gmail.com wrote: > From: Amir Mizinski <amirmizi6@gmail.com> > > Detected an incorrect implementation of the send command. > Currently, the driver polls the TPM_STS.stsValid field until TRUE; then it > reads TPM_STS register again to verify only that TPM_STS.expect field is > FALSE (i.e., it ignores TPM_STS.stsValid). > Since TPM_STS.stsValid represents the TPM_STS.expect validity, both fields > fields should be checked in the same TPM_STS register read value. This is missing description of what kind of error/consquence this caused. Perhaps you got something to the klog, or how did you find out about the issue? Since you have reproduced, please connect it to the reality. > Modify the signature of 'wait_for_tpm_stat()', add an additional > "mask_result" parameter to its call and rename it to > 'tpm_tis_wait_for_stat()' for better alignment with other naming. > 'tpm_tis_wait_for_stat()' is now polling the TPM_STS with a mask and waits > for the value in mask_result. Add the ability to check if certain TPM_STS > bits have been cleared. The commit description is probably out of sync (not only rename, there is no parameter called mask_result). It's also lacking description, how this new parameter is taken advantage of. E.g. "Use the new parameter to check that status TPM_STS_VALID is set, in addition that TPM_STS_EXPECT is zeroed. This prevents a racy checkk > In addition, the send command was changed to comply with > TCG_DesignPrinciples_TPM2p0Driver_vp24_pubrev.pdf as follows: > - send all command bytes in one loop > - remove special handling of the last byte > > Suggested-by: Benoit Houyere <benoit.houyere@st.com> > Signed-off-by: Amir Mizinski <amirmizi6@gmail.com> > --- > drivers/char/tpm/tpm_tis_core.c | 68 +++++++++++++++-------------------------- > 1 file changed, 25 insertions(+), 43 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index 69579ef..7d5854b 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -44,9 +44,9 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, > return false; > } > > -static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > - unsigned long timeout, wait_queue_head_t *queue, > - bool check_cancel) > +static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, u8 stat, > + unsigned long timeout, > + wait_queue_head_t *queue, bool check_cancel) This naming is not too great, considering that there is already local variable called status. > { > unsigned long stop; > long rc; > @@ -55,7 +55,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > > /* check current status */ > status = chip->ops->status(chip); > - if ((status & mask) == mask) > + if ((status & mask) == stat) > return 0; > > stop = jiffies + timeout; > @@ -83,7 +83,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > usleep_range(TPM_TIMEOUT_USECS_MIN, > TPM_TIMEOUT_USECS_MAX); > status = chip->ops->status(chip); > - if ((status & mask) == mask) > + if ((status & mask) == stat) > return 0; > } while (time_before(jiffies, stop)); > } > @@ -260,9 +260,10 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) > > while (size < count) { > rc = wait_for_tpm_stat(chip, > - TPM_STS_DATA_AVAIL | TPM_STS_VALID, > - chip->timeout_c, > - &priv->read_queue, true); > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > + chip->timeout_c, &priv->read_queue, > + true); > if (rc < 0) > return rc; > burstcnt = get_burstcount(chip); > @@ -315,8 +316,9 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) > goto out; > } > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > - &priv->int_queue, false) < 0) { > + if (wait_for_tpm_stat(chip, TPM_STS_VALID, TPM_STS_VALID, > + chip->timeout_c, &priv->int_queue, > + false) < 0) { > size = -ETIME; > goto out; > } > @@ -342,61 +344,40 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > int rc, status, burstcnt; > size_t count = 0; > - bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; > > status = tpm_tis_status(chip); > if ((status & TPM_STS_COMMAND_READY) == 0) { > tpm_tis_ready(chip); > - if (wait_for_tpm_stat > - (chip, TPM_STS_COMMAND_READY, chip->timeout_b, > - &priv->int_queue, false) < 0) { > + if (wait_for_tpm_stat(chip, TPM_STS_COMMAND_READY, > + TPM_STS_COMMAND_READY, > + chip->timeout_b, &priv->int_queue, > + false) < 0) { > rc = -ETIME; > goto out_err; > } > } > > - while (count < len - 1) { > + while (count < len) { This. > burstcnt = get_burstcount(chip); > if (burstcnt < 0) { > dev_err(&chip->dev, "Unable to read burstcount\n"); > rc = burstcnt; > goto out_err; > } > - burstcnt = min_t(int, burstcnt, len - count - 1); > + burstcnt = min_t(int, burstcnt, len - count); What are these two changes (loop condition and the right above change)? > rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), > burstcnt, buf + count); > if (rc < 0) > goto out_err; > > count += burstcnt; > - > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > - &priv->int_queue, false) < 0) { > - rc = -ETIME; > - goto out_err; > - } > - status = tpm_tis_status(chip); > - if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { > - rc = -EIO; > - goto out_err; > - } > } > - > - /* write last byte */ > - rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]); > - if (rc < 0) > - goto out_err; > - > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > - &priv->int_queue, false) < 0) { > + if (wait_for_tpm_stat(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT, > + TPM_STS_VALID, chip->timeout_a, > + &priv->int_queue, false) < 0) { > rc = -ETIME; > goto out_err; > } > - status = tpm_tis_status(chip); > - if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { > - rc = -EIO; > - goto out_err; > - } > > return 0; > > @@ -451,9 +432,10 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) > ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); > > dur = tpm_calc_ordinal_duration(chip, ordinal); > - if (wait_for_tpm_stat > - (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur, > - &priv->read_queue, false) < 0) { > + if (wait_for_tpm_stat(chip, > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > + dur, &priv->read_queue, false) < 0) { > rc = -ETIME; > goto out_err; > } /Jarkko
Hello Jarkko, apologies for the delay and thank you for your comments. I'll answer your comments below. On Tue, 14 Sept 2021 at 19:58, Jarkko Sakkinen <jarkko@kernel.org> wrote: > > On Tue, 2021-09-14 at 18:10 +0300, amirmizi6@gmail.com wrote: > > From: Amir Mizinski <amirmizi6@gmail.com> > > > > Detected an incorrect implementation of the send command. > > Currently, the driver polls the TPM_STS.stsValid field until TRUE; then it > > reads TPM_STS register again to verify only that TPM_STS.expect field is > > FALSE (i.e., it ignores TPM_STS.stsValid). > > Since TPM_STS.stsValid represents the TPM_STS.expect validity, both fields > > fields should be checked in the same TPM_STS register read value. > > This is missing description of what kind of error/consquence this caused. > Perhaps you got something to the klog, or how did you find out about the > issue? Since you have reproduced, please connect it to the reality. > We found out about this issue in a code review, and there's no specific error i can reproduce. The main problem here is that the current check is meaningless. Since TPM_STS.stsValid represents only the validity of the other bits on TPM_STS it makes no sense to check it on its own. Maybe it's better if i'll add a fix tag in here? > > Modify the signature of 'wait_for_tpm_stat()', add an additional > > "mask_result" parameter to its call and rename it to > > 'tpm_tis_wait_for_stat()' for better alignment with other naming. > > 'tpm_tis_wait_for_stat()' is now polling the TPM_STS with a mask and waits > > for the value in mask_result. Add the ability to check if certain TPM_STS > > bits have been cleared. > > The commit description is probably out of sync (not only rename, there is no > parameter called mask_result). > > It's also lacking description, how this new parameter is taken advantage of. > > E.g. > > "Use the new parameter to check that status TPM_STS_VALID is set, > in addition that TPM_STS_EXPECT is zeroed. This prevents a racy > checkk > Duly noted, ill fix this for next version. > > > In addition, the send command was changed to comply with > > TCG_DesignPrinciples_TPM2p0Driver_vp24_pubrev.pdf as follows: > > - send all command bytes in one loop > > - remove special handling of the last byte > > > > Suggested-by: Benoit Houyere <benoit.houyere@st.com> > > Signed-off-by: Amir Mizinski <amirmizi6@gmail.com> > > --- > > drivers/char/tpm/tpm_tis_core.c | 68 +++++++++++++++-------------------------- > > 1 file changed, 25 insertions(+), 43 deletions(-) > > > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > > index 69579ef..7d5854b 100644 > > --- a/drivers/char/tpm/tpm_tis_core.c > > +++ b/drivers/char/tpm/tpm_tis_core.c > > @@ -44,9 +44,9 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, > > return false; > > } > > > > -static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > > - unsigned long timeout, wait_queue_head_t *queue, > > - bool check_cancel) > > +static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, u8 stat, > > + unsigned long timeout, > > + wait_queue_head_t *queue, bool check_cancel) > > This naming is not too great, considering that there is already local variable > called status. > i will change this to result. is that better? > > > { > > unsigned long stop; > > long rc; > > @@ -55,7 +55,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > > > > /* check current status */ > > status = chip->ops->status(chip); > > - if ((status & mask) == mask) > > + if ((status & mask) == stat) > > return 0; > > > > stop = jiffies + timeout; > > @@ -83,7 +83,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, > > usleep_range(TPM_TIMEOUT_USECS_MIN, > > TPM_TIMEOUT_USECS_MAX); > > status = chip->ops->status(chip); > > - if ((status & mask) == mask) > > + if ((status & mask) == stat) > > return 0; > > } while (time_before(jiffies, stop)); > > } > > @@ -260,9 +260,10 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) > > > > while (size < count) { > > rc = wait_for_tpm_stat(chip, > > - TPM_STS_DATA_AVAIL | TPM_STS_VALID, > > - chip->timeout_c, > > - &priv->read_queue, true); > > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > > + chip->timeout_c, &priv->read_queue, > > + true); > > if (rc < 0) > > return rc; > > burstcnt = get_burstcount(chip); > > @@ -315,8 +316,9 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) > > goto out; > > } > > > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > > - &priv->int_queue, false) < 0) { > > + if (wait_for_tpm_stat(chip, TPM_STS_VALID, TPM_STS_VALID, > > + chip->timeout_c, &priv->int_queue, > > + false) < 0) { > > size = -ETIME; > > goto out; > > } > > @@ -342,61 +344,40 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) > > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > > int rc, status, burstcnt; > > size_t count = 0; > > - bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; > > > > status = tpm_tis_status(chip); > > if ((status & TPM_STS_COMMAND_READY) == 0) { > > tpm_tis_ready(chip); > > - if (wait_for_tpm_stat > > - (chip, TPM_STS_COMMAND_READY, chip->timeout_b, > > - &priv->int_queue, false) < 0) { > > + if (wait_for_tpm_stat(chip, TPM_STS_COMMAND_READY, > > + TPM_STS_COMMAND_READY, > > + chip->timeout_b, &priv->int_queue, > > + false) < 0) { > > rc = -ETIME; > > goto out_err; > > } > > } > > > > - while (count < len - 1) { > > + while (count < len) { > > This. > > > burstcnt = get_burstcount(chip); > > if (burstcnt < 0) { > > dev_err(&chip->dev, "Unable to read burstcount\n"); > > rc = burstcnt; > > goto out_err; > > } > > - burstcnt = min_t(int, burstcnt, len - count - 1); > > + burstcnt = min_t(int, burstcnt, len - count); > > What are these two changes (loop condition and the right above change)? > These changes are related to unnecessary handling of the last byte, this is described on the last paragraph of the commit message. > > rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), > > burstcnt, buf + count); > > if (rc < 0) > > goto out_err; > > > > count += burstcnt; > > - > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > > - &priv->int_queue, false) < 0) { > > - rc = -ETIME; > > - goto out_err; > > - } > > - status = tpm_tis_status(chip); > > - if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { > > - rc = -EIO; > > - goto out_err; > > - } > > } > > - > > - /* write last byte */ > > - rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]); > > - if (rc < 0) > > - goto out_err; > > - > > - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > > - &priv->int_queue, false) < 0) { > > + if (wait_for_tpm_stat(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT, > > + TPM_STS_VALID, chip->timeout_a, > > + &priv->int_queue, false) < 0) { > > rc = -ETIME; > > goto out_err; > > } > > - status = tpm_tis_status(chip); > > - if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { > > - rc = -EIO; > > - goto out_err; > > - } > > > > return 0; > > > > @@ -451,9 +432,10 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) > > ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); > > > > dur = tpm_calc_ordinal_duration(chip, ordinal); > > - if (wait_for_tpm_stat > > - (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur, > > - &priv->read_queue, false) < 0) { > > + if (wait_for_tpm_stat(chip, > > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > > + TPM_STS_DATA_AVAIL | TPM_STS_VALID, > > + dur, &priv->read_queue, false) < 0) { > > rc = -ETIME; > > goto out_err; > > } > > /Jarkko > Thank you, Amir Mizinski
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 69579ef..7d5854b 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -44,9 +44,9 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, return false; } -static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, - unsigned long timeout, wait_queue_head_t *queue, - bool check_cancel) +static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, u8 stat, + unsigned long timeout, + wait_queue_head_t *queue, bool check_cancel) { unsigned long stop; long rc; @@ -55,7 +55,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, /* check current status */ status = chip->ops->status(chip); - if ((status & mask) == mask) + if ((status & mask) == stat) return 0; stop = jiffies + timeout; @@ -83,7 +83,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX); status = chip->ops->status(chip); - if ((status & mask) == mask) + if ((status & mask) == stat) return 0; } while (time_before(jiffies, stop)); } @@ -260,9 +260,10 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) while (size < count) { rc = wait_for_tpm_stat(chip, - TPM_STS_DATA_AVAIL | TPM_STS_VALID, - chip->timeout_c, - &priv->read_queue, true); + TPM_STS_DATA_AVAIL | TPM_STS_VALID, + TPM_STS_DATA_AVAIL | TPM_STS_VALID, + chip->timeout_c, &priv->read_queue, + true); if (rc < 0) return rc; burstcnt = get_burstcount(chip); @@ -315,8 +316,9 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, - &priv->int_queue, false) < 0) { + if (wait_for_tpm_stat(chip, TPM_STS_VALID, TPM_STS_VALID, + chip->timeout_c, &priv->int_queue, + false) < 0) { size = -ETIME; goto out; } @@ -342,61 +344,40 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int rc, status, burstcnt; size_t count = 0; - bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; status = tpm_tis_status(chip); if ((status & TPM_STS_COMMAND_READY) == 0) { tpm_tis_ready(chip); - if (wait_for_tpm_stat - (chip, TPM_STS_COMMAND_READY, chip->timeout_b, - &priv->int_queue, false) < 0) { + if (wait_for_tpm_stat(chip, TPM_STS_COMMAND_READY, + TPM_STS_COMMAND_READY, + chip->timeout_b, &priv->int_queue, + false) < 0) { rc = -ETIME; goto out_err; } } - while (count < len - 1) { + while (count < len) { burstcnt = get_burstcount(chip); if (burstcnt < 0) { dev_err(&chip->dev, "Unable to read burstcount\n"); rc = burstcnt; goto out_err; } - burstcnt = min_t(int, burstcnt, len - count - 1); + burstcnt = min_t(int, burstcnt, len - count); rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), burstcnt, buf + count); if (rc < 0) goto out_err; count += burstcnt; - - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, - &priv->int_queue, false) < 0) { - rc = -ETIME; - goto out_err; - } - status = tpm_tis_status(chip); - if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { - rc = -EIO; - goto out_err; - } } - - /* write last byte */ - rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]); - if (rc < 0) - goto out_err; - - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, - &priv->int_queue, false) < 0) { + if (wait_for_tpm_stat(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT, + TPM_STS_VALID, chip->timeout_a, + &priv->int_queue, false) < 0) { rc = -ETIME; goto out_err; } - status = tpm_tis_status(chip); - if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { - rc = -EIO; - goto out_err; - } return 0; @@ -451,9 +432,10 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); dur = tpm_calc_ordinal_duration(chip, ordinal); - if (wait_for_tpm_stat - (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur, - &priv->read_queue, false) < 0) { + if (wait_for_tpm_stat(chip, + TPM_STS_DATA_AVAIL | TPM_STS_VALID, + TPM_STS_DATA_AVAIL | TPM_STS_VALID, + dur, &priv->read_queue, false) < 0) { rc = -ETIME; goto out_err; }