forked from luck/tmp_suning_uos_patched
tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure
1. Use tpm_buf in tpm1_get_random() 2. Fix comment in tpm_get_random() so it is clear that the function is expected to return number of random bytes. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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c22780ff0c
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@ -600,7 +600,7 @@ EXPORT_SYMBOL_GPL(tpm_pm_resume);
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* @out: destination buffer for the random bytes
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* @max: the max number of bytes to write to @out
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*
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* Return: same as with tpm_transmit_cmd()
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* Return: number of random bytes read or a negative error value.
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*/
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int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
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{
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@ -396,20 +396,9 @@ struct tpm_pcrread_in {
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* compiler warnings about stack frame size. */
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#define TPM_MAX_RNG_DATA 128
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struct tpm_getrandom_out {
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__be32 rng_data_len;
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u8 rng_data[TPM_MAX_RNG_DATA];
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} __packed;
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struct tpm_getrandom_in {
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__be32 num_bytes;
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} __packed;
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typedef union {
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struct tpm_pcrread_in pcrread_in;
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struct tpm_pcrread_out pcrread_out;
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struct tpm_getrandom_in getrandom_in;
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struct tpm_getrandom_out getrandom_out;
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} tpm_cmd_params;
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struct tpm_cmd_t {
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@ -505,58 +505,70 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
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EXPORT_SYMBOL_GPL(tpm1_getcap);
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#define TPM_ORD_GET_RANDOM 70
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#define TPM_GETRANDOM_RESULT_SIZE 18
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static const struct tpm_input_header tpm_getrandom_header = {
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.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
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.length = cpu_to_be32(14),
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.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
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};
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struct tpm1_get_random_out {
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__be32 rng_data_len;
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u8 rng_data[TPM_MAX_RNG_DATA];
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} __packed;
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int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)
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/**
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* tpm1_get_random() - get random bytes from the TPM's RNG
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* @chip: a &struct tpm_chip instance
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* @dest: destination buffer for the random bytes
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* @max: the maximum number of bytes to write to @dest
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*
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* Return:
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* * number of bytes read
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* * -errno or a TPM return code otherwise
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*/
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int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
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{
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struct tpm_cmd_t tpm_cmd;
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struct tpm1_get_random_out *out;
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u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
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struct tpm_buf buf;
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u32 total = 0;
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int retries = 5;
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u32 recd;
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u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
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u32 rlength;
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int err, total = 0, retries = 5;
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u8 *dest = out;
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int rc;
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if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
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return -EINVAL;
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rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
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if (rc)
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return rc;
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do {
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tpm_cmd.header.in = tpm_getrandom_header;
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tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
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tpm_buf_append_u32(&buf, num_bytes);
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err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
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TPM_GETRANDOM_RESULT_SIZE + num_bytes,
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offsetof(struct tpm_getrandom_out,
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rng_data),
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0, "attempting get random");
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if (err)
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break;
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rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
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sizeof(out->rng_data_len), 0,
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"attempting get random");
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if (rc)
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goto out;
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recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
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out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
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recd = be32_to_cpu(out->rng_data_len);
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if (recd > num_bytes) {
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total = -EFAULT;
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break;
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rc = -EFAULT;
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goto out;
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}
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rlength = be32_to_cpu(tpm_cmd.header.out.length);
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if (rlength < TPM_HEADER_SIZE +
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offsetof(struct tpm_getrandom_out, rng_data) +
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recd) {
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total = -EFAULT;
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break;
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if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
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sizeof(out->rng_data_len) + recd) {
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rc = -EFAULT;
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goto out;
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}
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memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
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memcpy(dest, out->rng_data, recd);
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dest += recd;
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total += recd;
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num_bytes -= recd;
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} while (retries-- && (size_t)total < max);
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return total ? total : -EIO;
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tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
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} while (retries-- && total < max);
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rc = total ? (int)total : -EIO;
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out:
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tpm_buf_destroy(&buf);
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return rc;
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}
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#define TPM_ORDINAL_PCRREAD 21
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