From 304ff672537c25339578273487a1d84e4936e006 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Sun, 4 Nov 2018 16:15:49 +0200 Subject: tpm: clean up tpm_try_transmit() error handling flow Move locking, locality handling and power management to tpm_transmit() in order to simplify the flow. Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger Tested-by: Stefan Berger Reviewed-by: Jerry Snitselaar Reviewed-by: James Bottomley Tested-by: Alexander Steffen --- drivers/char/tpm/tpm-interface.c | 94 ++++++++++++++++++---------------------- 1 file changed, 43 insertions(+), 51 deletions(-) (limited to 'drivers/char/tpm/tpm-interface.c') diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 7870e3178ada..ce06e66b4400 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -167,7 +167,6 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space, ssize_t len = 0; u32 count, ordinal; unsigned long stop; - bool need_locality; rc = tpm_validate_command(chip, space, buf, bufsiz); if (rc == -EINVAL) @@ -197,37 +196,16 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space, return -E2BIG; } - if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED)) - mutex_lock(&chip->tpm_mutex); - - if (chip->ops->clk_enable != NULL) - chip->ops->clk_enable(chip, true); - - /* Store the decision as chip->locality will be changed. */ - need_locality = chip->locality == -1; - - if (need_locality) { - rc = tpm_request_locality(chip, flags); - if (rc < 0) { - need_locality = false; - goto out_locality; - } - } - - rc = tpm_cmd_ready(chip, flags); - if (rc) - goto out_locality; - rc = tpm2_prepare_space(chip, space, ordinal, buf); if (rc) - goto out; + return rc; rc = chip->ops->send(chip, buf, count); if (rc < 0) { if (rc != -EPIPE) dev_err(&chip->dev, "%s: send(): error %d\n", __func__, rc); - goto out; + goto out_rc; } /* A sanity check. send() should just return zero on success e.g. @@ -252,7 +230,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space, if (chip->ops->req_canceled(chip, status)) { dev_err(&chip->dev, "Operation Canceled\n"); rc = -ECANCELED; - goto out; + goto out_rc; } tpm_msleep(TPM_TIMEOUT_POLL); @@ -262,40 +240,20 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space, chip->ops->cancel(chip); dev_err(&chip->dev, "Operation Timed out\n"); rc = -ETIME; - goto out; + goto out_rc; out_recv: len = chip->ops->recv(chip, buf, bufsiz); if (len < 0) { rc = len; - dev_err(&chip->dev, - "tpm_transmit: tpm_recv: error %d\n", rc); - goto out; - } else if (len < TPM_HEADER_SIZE) { + dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc); + } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length)) rc = -EFAULT; - goto out; - } - if (len != be32_to_cpu(header->length)) { - rc = -EFAULT; - goto out; - } - - rc = tpm2_commit_space(chip, space, ordinal, buf, &len); +out_rc: + if (!rc) + rc = tpm2_commit_space(chip, space, ordinal, buf, &len); -out: - /* may fail but do not override previous error value in rc */ - tpm_go_idle(chip, flags); - -out_locality: - if (need_locality) - tpm_relinquish_locality(chip, flags); - - if (chip->ops->clk_enable != NULL) - chip->ops->clk_enable(chip, false); - - if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED)) - mutex_unlock(&chip->tpm_mutex); return rc ? rc : len; } @@ -325,6 +283,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, /* space for header and handles */ u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)]; unsigned int delay_msec = TPM2_DURATION_SHORT; + bool has_locality = false; u32 rc = 0; ssize_t ret; const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE, @@ -340,7 +299,40 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, memcpy(save, buf, save_size); for (;;) { + if (!(flags & TPM_TRANSMIT_UNLOCKED) && + !(flags & TPM_TRANSMIT_NESTED)) + mutex_lock(&chip->tpm_mutex); + + if (chip->ops->clk_enable != NULL) + chip->ops->clk_enable(chip, true); + + if (chip->locality == -1) { + ret = tpm_request_locality(chip, flags); + if (ret) + goto out_locality; + has_locality = true; + } + + ret = tpm_cmd_ready(chip, flags); + if (ret) + goto out_locality; + ret = tpm_try_transmit(chip, space, buf, bufsiz, flags); + + /* This may fail but do not override ret. */ + tpm_go_idle(chip, flags); + +out_locality: + if (has_locality) + tpm_relinquish_locality(chip, flags); + + if (chip->ops->clk_enable != NULL) + chip->ops->clk_enable(chip, false); + + if (!(flags & TPM_TRANSMIT_UNLOCKED) && + !(flags & TPM_TRANSMIT_NESTED)) + mutex_unlock(&chip->tpm_mutex); + if (ret < 0) break; rc = be32_to_cpu(header->return_code); -- cgit v1.2.3-59-g8ed1b