tpm1_get_random() and tpm2_get_random() contain duplicate orchestration
code. Consolidate orchestration to tpm_get_random().
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
drivers/char/tpm/tpm-interface.c | 175 +++++++++++++++++++++++++++++--
drivers/char/tpm/tpm.h | 2 -
drivers/char/tpm/tpm1-cmd.c | 69 ------------
drivers/char/tpm/tpm2-cmd.c | 104 ------------------
4 files changed, 164 insertions(+), 186 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index f745a098908b..d157be738612 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -26,7 +26,7 @@
#include <linux/suspend.h>
#include <linux/freezer.h>
#include <linux/tpm_eventlog.h>
-
+#include <linux/tpm_command.h>
#include "tpm.h"
/*
@@ -486,19 +486,153 @@ int tpm_pm_resume(struct device *dev)
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
+struct tpm1_get_random_out {
+ __be32 rng_data_len;
+ u8 rng_data[TPM_MAX_RNG_DATA];
+} __packed;
+
+static int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ struct tpm1_get_random_out *resp;
+ struct tpm_buf buf;
+ u32 recd;
+ int rc;
+
+ if (!out || !max || max > TPM_MAX_RNG_DATA)
+ return -EINVAL;
+
+ rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GETRANDOM);
+ if (rc)
+ return rc;
+
+ tpm_buf_append_u32(&buf, max);
+
+ rc = tpm_transmit_cmd(chip, &buf, sizeof(resp->rng_data_len), "TPM_GetRandom");
+ if (rc) {
+ if (rc > 0)
+ rc = -EIO;
+ goto err;
+ }
+
+ resp = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
+
+ recd = be32_to_cpu(resp->rng_data_len);
+ if (recd > max) {
+ rc = -EIO;
+ goto err;
+ }
+
+ if (buf.length < TPM_HEADER_SIZE + sizeof(resp->rng_data_len) + recd) {
+ rc = -EIO;
+ goto err;
+ }
+
+ memcpy(out, resp->rng_data, recd);
+ tpm_buf_destroy(&buf);
+ return recd;
+
+err:
+ tpm_buf_destroy(&buf);
+ return rc;
+}
+
+struct tpm2_get_random_out {
+ __be16 size;
+ u8 buffer[TPM_MAX_RNG_DATA];
+} __packed;
+
+static int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ struct tpm2_get_random_out *resp;
+ struct tpm_header *head;
+ struct tpm_buf buf;
+ off_t offset;
+ u32 recd;
+ int ret;
+
+ if (!out || !max || max > TPM_MAX_RNG_DATA)
+ return -EINVAL;
+
+ ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
+ if (ret)
+ return ret;
+
+ if (tpm2_chip_auth(chip)) {
+ tpm_buf_append_hmac_session(chip, &buf,
+ TPM2_SA_ENCRYPT | TPM2_SA_CONTINUE_SESSION,
+ NULL, 0);
+ } else {
+ head = (struct tpm_header *)buf.data;
+ head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
+ }
+ tpm_buf_append_u16(&buf, max);
+
+ ret = tpm_buf_fill_hmac_session(chip, &buf);
+ if (ret) {
+ tpm_buf_destroy(&buf);
+ return ret;
+ }
+
+ ret = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer),
+ "TPM2_GetRandom");
+
+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
+ if (ret) {
+ if (ret > 0)
+ ret = -EIO;
+
+ goto out;
+ }
+
+ head = (struct tpm_header *)buf.data;
+ offset = TPM_HEADER_SIZE;
+
+ /* Skip the parameter size field: */
+ if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
+ offset += 4;
+
+ resp = (struct tpm2_get_random_out *)&buf.data[offset];
+ recd = min_t(u32, be16_to_cpu(resp->size), max);
+
+ if (tpm_buf_length(&buf) <
+ TPM_HEADER_SIZE + offsetof(struct tpm2_get_random_out, buffer) + recd) {
+ ret = -EIO;
+ goto out;
+ }
+
+ memcpy(out, resp->buffer, recd);
+ return recd;
+
+out:
+ tpm2_end_auth_session(chip);
+ tpm_buf_destroy(&buf);
+ return ret;
+}
+
/**
- * tpm_get_random() - get random bytes from the TPM's RNG
- * @chip: a &struct tpm_chip instance, %NULL for the default chip
- * @out: destination buffer for the random bytes
- * @max: the max number of bytes to write to @out
+ * tpm_get_random() - Get random bytes from the TPM's RNG
+ * @chip: A &tpm_chip instance. Whenset to %NULL, the default chip is used.
+ * @out: Destination buffer for the acquired random bytes.
+ * @max: The maximum number of bytes to write to @out.
+ *
+ * Iterates pulling more bytes from TPM up until all of the @max bytes have been
+ * received.
*
- * Return: number of random bytes read or a negative error value.
+ * Returns the number of random bytes read on success.
+ * Returns -EINVAL when @out is NULL, or @max is not between zero and
+ * %TPM_MAX_RNG_DATA.
+ * Returns tpm_transmit_cmd() error codes when the TPM command results an
+ * error.
*/
int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
+ u32 num_bytes = max;
+ u8 *out_ptr = out;
+ int retries = 5;
+ int total = 0;
int rc;
- if (!out || max > TPM_MAX_RNG_DATA)
+ if (!out || !max || max > TPM_MAX_RNG_DATA)
return -EINVAL;
if (!chip)
@@ -508,11 +642,30 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
if (rc)
return rc;
- if (chip->flags & TPM_CHIP_FLAG_TPM2)
- rc = tpm2_get_random(chip, out, max);
- else
- rc = tpm1_get_random(chip, out, max);
+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+ rc = tpm2_start_auth_session(chip);
+ if (rc)
+ return rc;
+ }
+
+ do {
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_get_random(chip, out_ptr, num_bytes);
+ else
+ rc = tpm1_get_random(chip, out_ptr, num_bytes);
+
+ if (rc < 0)
+ goto err;
+
+ out_ptr += rc;
+ total += rc;
+ num_bytes -= rc;
+ } while (retries-- && total < max);
+
+ tpm_put_ops(chip);
+ return total ? total : -EIO;
+err:
tpm_put_ops(chip);
return rc;
}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 02c07fef41ba..f698d01401de 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -251,7 +251,6 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
const char *desc, size_t min_cap_length);
-int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max);
int tpm1_get_pcr_allocation(struct tpm_chip *chip);
unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
int tpm_pm_suspend(struct device *dev);
@@ -291,7 +290,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digest, u16 *digest_size_ptr);
int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digests);
-int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
u32 *value, const char *desc);
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index b49a790f1bd5..0604e11c9778 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -511,75 +511,6 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
}
EXPORT_SYMBOL_GPL(tpm1_getcap);
-#define TPM_ORD_GET_RANDOM 70
-struct tpm1_get_random_out {
- __be32 rng_data_len;
- u8 rng_data[TPM_MAX_RNG_DATA];
-} __packed;
-
-/**
- * tpm1_get_random() - get random bytes from the TPM's RNG
- * @chip: a &struct tpm_chip instance
- * @dest: destination buffer for the random bytes
- * @max: the maximum number of bytes to write to @dest
- *
- * Return:
- * * number of bytes read
- * * -errno (positive TPM return codes are masked to -EIO)
- */
-int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
-{
- struct tpm1_get_random_out *out;
- u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
- struct tpm_buf buf;
- u32 total = 0;
- int retries = 5;
- u32 recd;
- int rc;
-
- rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
- if (rc)
- return rc;
-
- do {
- tpm_buf_append_u32(&buf, num_bytes);
-
- rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
- "attempting get random");
- if (rc) {
- if (rc > 0)
- rc = -EIO;
- goto out;
- }
-
- out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
-
- recd = be32_to_cpu(out->rng_data_len);
- if (recd > num_bytes) {
- rc = -EFAULT;
- goto out;
- }
-
- if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
- sizeof(out->rng_data_len) + recd) {
- rc = -EFAULT;
- goto out;
- }
- memcpy(dest, out->rng_data, recd);
-
- dest += recd;
- total += recd;
- num_bytes -= recd;
-
- tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
- } while (retries-- && total < max);
-
- rc = total ? (int)total : -EIO;
-out:
- tpm_buf_destroy(&buf);
- return rc;
-}
-
#define TPM_ORD_PCRREAD 21
int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
{
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 3a77be7ebf4a..34168d5f9c78 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -238,110 +238,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
return rc;
}
-struct tpm2_get_random_out {
- __be16 size;
- u8 buffer[TPM_MAX_RNG_DATA];
-} __packed;
-
-/**
- * tpm2_get_random() - get random bytes from the TPM RNG
- *
- * @chip: a &tpm_chip instance
- * @dest: destination buffer
- * @max: the max number of random bytes to pull
- *
- * Return:
- * size of the buffer on success,
- * -errno otherwise (positive TPM return codes are masked to -EIO)
- */
-int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
-{
- struct tpm2_get_random_out *out;
- struct tpm_header *head;
- struct tpm_buf buf;
- u32 recd;
- u32 num_bytes = max;
- int err;
- int total = 0;
- int retries = 5;
- u8 *dest_ptr = dest;
- off_t offset;
-
- if (!num_bytes || max > TPM_MAX_RNG_DATA)
- return -EINVAL;
-
- err = tpm2_start_auth_session(chip);
- if (err)
- return err;
-
- err = tpm_buf_init(&buf, 0, 0);
- if (err) {
- tpm2_end_auth_session(chip);
- return err;
- }
-
- do {
- tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
- if (tpm2_chip_auth(chip)) {
- tpm_buf_append_hmac_session(chip, &buf,
- TPM2_SA_ENCRYPT |
- TPM2_SA_CONTINUE_SESSION,
- NULL, 0);
- } else {
- offset = buf.handles * 4 + TPM_HEADER_SIZE;
- head = (struct tpm_header *)buf.data;
- if (tpm_buf_length(&buf) == offset)
- head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
- }
- tpm_buf_append_u16(&buf, num_bytes);
- err = tpm_buf_fill_hmac_session(chip, &buf);
- if (err) {
- tpm_buf_destroy(&buf);
- return err;
- }
-
- err = tpm_transmit_cmd(chip, &buf,
- offsetof(struct tpm2_get_random_out,
- buffer),
- "attempting get random");
- err = tpm_buf_check_hmac_response(chip, &buf, err);
- if (err) {
- if (err > 0)
- err = -EIO;
- goto out;
- }
-
- head = (struct tpm_header *)buf.data;
- offset = TPM_HEADER_SIZE;
- /* Skip the parameter size field: */
- if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
- offset += 4;
-
- out = (struct tpm2_get_random_out *)&buf.data[offset];
- recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
- if (tpm_buf_length(&buf) <
- TPM_HEADER_SIZE +
- offsetof(struct tpm2_get_random_out, buffer) +
- recd) {
- err = -EFAULT;
- goto out;
- }
- memcpy(dest_ptr, out->buffer, recd);
-
- dest_ptr += recd;
- total += recd;
- num_bytes -= recd;
- } while (retries-- && total < max);
-
- tpm_buf_destroy(&buf);
-
- return total ? total : -EIO;
-out:
- tpm_buf_destroy(&buf);
- tpm2_end_auth_session(chip);
- return err;
-}
-
/**
* tpm2_flush_context() - execute a TPM2_FlushContext command
* @chip: TPM chip to use
--
2.39.5On Tue, Dec 16, 2025 at 11:21:37AM +0200, Jarkko Sakkinen wrote:
>tpm1_get_random() and tpm2_get_random() contain duplicate orchestration
>code. Consolidate orchestration to tpm_get_random().
Does keeping the respective tpm1/tpm2 bits in their -cmd.c files not
make more sense, still allowing for the consolidation of orchestration
in tpm_get_random?
>Cc: Eric Biggers <ebiggers@kernel.org>
>Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
>---
> drivers/char/tpm/tpm-interface.c | 175 +++++++++++++++++++++++++++++--
> drivers/char/tpm/tpm.h | 2 -
> drivers/char/tpm/tpm1-cmd.c | 69 ------------
> drivers/char/tpm/tpm2-cmd.c | 104 ------------------
> 4 files changed, 164 insertions(+), 186 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
>index f745a098908b..d157be738612 100644
>--- a/drivers/char/tpm/tpm-interface.c
>+++ b/drivers/char/tpm/tpm-interface.c
>@@ -26,7 +26,7 @@
> #include <linux/suspend.h>
> #include <linux/freezer.h>
> #include <linux/tpm_eventlog.h>
>-
>+#include <linux/tpm_command.h>
> #include "tpm.h"
>
> /*
>@@ -486,19 +486,153 @@ int tpm_pm_resume(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(tpm_pm_resume);
>
>+struct tpm1_get_random_out {
>+ __be32 rng_data_len;
>+ u8 rng_data[TPM_MAX_RNG_DATA];
>+} __packed;
>+
>+static int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)
>+{
>+ struct tpm1_get_random_out *resp;
>+ struct tpm_buf buf;
>+ u32 recd;
>+ int rc;
>+
>+ if (!out || !max || max > TPM_MAX_RNG_DATA)
>+ return -EINVAL;
>+
>+ rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GETRANDOM);
>+ if (rc)
>+ return rc;
>+
>+ tpm_buf_append_u32(&buf, max);
>+
>+ rc = tpm_transmit_cmd(chip, &buf, sizeof(resp->rng_data_len), "TPM_GetRandom");
>+ if (rc) {
>+ if (rc > 0)
>+ rc = -EIO;
>+ goto err;
>+ }
>+
>+ resp = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
>+
>+ recd = be32_to_cpu(resp->rng_data_len);
>+ if (recd > max) {
>+ rc = -EIO;
>+ goto err;
>+ }
>+
>+ if (buf.length < TPM_HEADER_SIZE + sizeof(resp->rng_data_len) + recd) {
>+ rc = -EIO;
>+ goto err;
>+ }
>+
>+ memcpy(out, resp->rng_data, recd);
>+ tpm_buf_destroy(&buf);
>+ return recd;
>+
>+err:
>+ tpm_buf_destroy(&buf);
>+ return rc;
>+}
>+
>+struct tpm2_get_random_out {
>+ __be16 size;
>+ u8 buffer[TPM_MAX_RNG_DATA];
>+} __packed;
>+
>+static int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
>+{
>+ struct tpm2_get_random_out *resp;
>+ struct tpm_header *head;
>+ struct tpm_buf buf;
>+ off_t offset;
>+ u32 recd;
>+ int ret;
>+
>+ if (!out || !max || max > TPM_MAX_RNG_DATA)
>+ return -EINVAL;
>+
>+ ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
>+ if (ret)
>+ return ret;
>+
>+ if (tpm2_chip_auth(chip)) {
>+ tpm_buf_append_hmac_session(chip, &buf,
>+ TPM2_SA_ENCRYPT | TPM2_SA_CONTINUE_SESSION,
>+ NULL, 0);
>+ } else {
>+ head = (struct tpm_header *)buf.data;
>+ head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
>+ }
>+ tpm_buf_append_u16(&buf, max);
>+
>+ ret = tpm_buf_fill_hmac_session(chip, &buf);
>+ if (ret) {
>+ tpm_buf_destroy(&buf);
>+ return ret;
>+ }
>+
>+ ret = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer),
>+ "TPM2_GetRandom");
>+
>+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
>+ if (ret) {
>+ if (ret > 0)
>+ ret = -EIO;
>+
>+ goto out;
>+ }
>+
>+ head = (struct tpm_header *)buf.data;
>+ offset = TPM_HEADER_SIZE;
>+
>+ /* Skip the parameter size field: */
>+ if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
>+ offset += 4;
>+
>+ resp = (struct tpm2_get_random_out *)&buf.data[offset];
>+ recd = min_t(u32, be16_to_cpu(resp->size), max);
>+
>+ if (tpm_buf_length(&buf) <
>+ TPM_HEADER_SIZE + offsetof(struct tpm2_get_random_out, buffer) + recd) {
>+ ret = -EIO;
>+ goto out;
>+ }
>+
>+ memcpy(out, resp->buffer, recd);
>+ return recd;
>+
>+out:
>+ tpm2_end_auth_session(chip);
>+ tpm_buf_destroy(&buf);
>+ return ret;
>+}
>+
> /**
>- * tpm_get_random() - get random bytes from the TPM's RNG
>- * @chip: a &struct tpm_chip instance, %NULL for the default chip
>- * @out: destination buffer for the random bytes
>- * @max: the max number of bytes to write to @out
>+ * tpm_get_random() - Get random bytes from the TPM's RNG
>+ * @chip: A &tpm_chip instance. Whenset to %NULL, the default chip is used.
>+ * @out: Destination buffer for the acquired random bytes.
>+ * @max: The maximum number of bytes to write to @out.
>+ *
>+ * Iterates pulling more bytes from TPM up until all of the @max bytes have been
>+ * received.
> *
>- * Return: number of random bytes read or a negative error value.
>+ * Returns the number of random bytes read on success.
>+ * Returns -EINVAL when @out is NULL, or @max is not between zero and
>+ * %TPM_MAX_RNG_DATA.
>+ * Returns tpm_transmit_cmd() error codes when the TPM command results an
>+ * error.
> */
> int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
> {
>+ u32 num_bytes = max;
>+ u8 *out_ptr = out;
>+ int retries = 5;
>+ int total = 0;
> int rc;
>
>- if (!out || max > TPM_MAX_RNG_DATA)
>+ if (!out || !max || max > TPM_MAX_RNG_DATA)
> return -EINVAL;
>
> if (!chip)
>@@ -508,11 +642,30 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
> if (rc)
> return rc;
>
>- if (chip->flags & TPM_CHIP_FLAG_TPM2)
>- rc = tpm2_get_random(chip, out, max);
>- else
>- rc = tpm1_get_random(chip, out, max);
>+ if (chip->flags & TPM_CHIP_FLAG_TPM2) {
>+ rc = tpm2_start_auth_session(chip);
>+ if (rc)
>+ return rc;
>+ }
>+
>+ do {
>+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
>+ rc = tpm2_get_random(chip, out_ptr, num_bytes);
>+ else
>+ rc = tpm1_get_random(chip, out_ptr, num_bytes);
>+
>+ if (rc < 0)
>+ goto err;
>+
>+ out_ptr += rc;
>+ total += rc;
>+ num_bytes -= rc;
>+ } while (retries-- && total < max);
>+
>+ tpm_put_ops(chip);
>+ return total ? total : -EIO;
>
>+err:
> tpm_put_ops(chip);
> return rc;
> }
>diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
>index 02c07fef41ba..f698d01401de 100644
>--- a/drivers/char/tpm/tpm.h
>+++ b/drivers/char/tpm/tpm.h
>@@ -251,7 +251,6 @@ int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
> int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
> ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> const char *desc, size_t min_cap_length);
>-int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max);
> int tpm1_get_pcr_allocation(struct tpm_chip *chip);
> unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
> int tpm_pm_suspend(struct device *dev);
>@@ -291,7 +290,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
> struct tpm_digest *digest, u16 *digest_size_ptr);
> int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> struct tpm_digest *digests);
>-int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
> ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
> u32 *value, const char *desc);
>
>diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
>index b49a790f1bd5..0604e11c9778 100644
>--- a/drivers/char/tpm/tpm1-cmd.c
>+++ b/drivers/char/tpm/tpm1-cmd.c
>@@ -511,75 +511,6 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
> }
> EXPORT_SYMBOL_GPL(tpm1_getcap);
>
>-#define TPM_ORD_GET_RANDOM 70
>-struct tpm1_get_random_out {
>- __be32 rng_data_len;
>- u8 rng_data[TPM_MAX_RNG_DATA];
>-} __packed;
>-
>-/**
>- * tpm1_get_random() - get random bytes from the TPM's RNG
>- * @chip: a &struct tpm_chip instance
>- * @dest: destination buffer for the random bytes
>- * @max: the maximum number of bytes to write to @dest
>- *
>- * Return:
>- * * number of bytes read
>- * * -errno (positive TPM return codes are masked to -EIO)
>- */
>-int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
>-{
>- struct tpm1_get_random_out *out;
>- u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
>- struct tpm_buf buf;
>- u32 total = 0;
>- int retries = 5;
>- u32 recd;
>- int rc;
>-
>- rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
>- if (rc)
>- return rc;
>-
>- do {
>- tpm_buf_append_u32(&buf, num_bytes);
>-
>- rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
>- "attempting get random");
>- if (rc) {
>- if (rc > 0)
>- rc = -EIO;
>- goto out;
>- }
>-
>- out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
>-
>- recd = be32_to_cpu(out->rng_data_len);
>- if (recd > num_bytes) {
>- rc = -EFAULT;
>- goto out;
>- }
>-
>- if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
>- sizeof(out->rng_data_len) + recd) {
>- rc = -EFAULT;
>- goto out;
>- }
>- memcpy(dest, out->rng_data, recd);
>-
>- dest += recd;
>- total += recd;
>- num_bytes -= recd;
>-
>- tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
>- } while (retries-- && total < max);
>-
>- rc = total ? (int)total : -EIO;
>-out:
>- tpm_buf_destroy(&buf);
>- return rc;
>-}
>-
> #define TPM_ORD_PCRREAD 21
> int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
> {
>diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
>index 3a77be7ebf4a..34168d5f9c78 100644
>--- a/drivers/char/tpm/tpm2-cmd.c
>+++ b/drivers/char/tpm/tpm2-cmd.c
>@@ -238,110 +238,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
> return rc;
> }
>
>-struct tpm2_get_random_out {
>- __be16 size;
>- u8 buffer[TPM_MAX_RNG_DATA];
>-} __packed;
>-
>-/**
>- * tpm2_get_random() - get random bytes from the TPM RNG
>- *
>- * @chip: a &tpm_chip instance
>- * @dest: destination buffer
>- * @max: the max number of random bytes to pull
>- *
>- * Return:
>- * size of the buffer on success,
>- * -errno otherwise (positive TPM return codes are masked to -EIO)
>- */
>-int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
>-{
>- struct tpm2_get_random_out *out;
>- struct tpm_header *head;
>- struct tpm_buf buf;
>- u32 recd;
>- u32 num_bytes = max;
>- int err;
>- int total = 0;
>- int retries = 5;
>- u8 *dest_ptr = dest;
>- off_t offset;
>-
>- if (!num_bytes || max > TPM_MAX_RNG_DATA)
>- return -EINVAL;
>-
>- err = tpm2_start_auth_session(chip);
>- if (err)
>- return err;
>-
>- err = tpm_buf_init(&buf, 0, 0);
>- if (err) {
>- tpm2_end_auth_session(chip);
>- return err;
>- }
>-
>- do {
>- tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
>- if (tpm2_chip_auth(chip)) {
>- tpm_buf_append_hmac_session(chip, &buf,
>- TPM2_SA_ENCRYPT |
>- TPM2_SA_CONTINUE_SESSION,
>- NULL, 0);
>- } else {
>- offset = buf.handles * 4 + TPM_HEADER_SIZE;
>- head = (struct tpm_header *)buf.data;
>- if (tpm_buf_length(&buf) == offset)
>- head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
>- }
>- tpm_buf_append_u16(&buf, num_bytes);
>- err = tpm_buf_fill_hmac_session(chip, &buf);
>- if (err) {
>- tpm_buf_destroy(&buf);
>- return err;
>- }
>-
>- err = tpm_transmit_cmd(chip, &buf,
>- offsetof(struct tpm2_get_random_out,
>- buffer),
>- "attempting get random");
>- err = tpm_buf_check_hmac_response(chip, &buf, err);
>- if (err) {
>- if (err > 0)
>- err = -EIO;
>- goto out;
>- }
>-
>- head = (struct tpm_header *)buf.data;
>- offset = TPM_HEADER_SIZE;
>- /* Skip the parameter size field: */
>- if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
>- offset += 4;
>-
>- out = (struct tpm2_get_random_out *)&buf.data[offset];
>- recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
>- if (tpm_buf_length(&buf) <
>- TPM_HEADER_SIZE +
>- offsetof(struct tpm2_get_random_out, buffer) +
>- recd) {
>- err = -EFAULT;
>- goto out;
>- }
>- memcpy(dest_ptr, out->buffer, recd);
>-
>- dest_ptr += recd;
>- total += recd;
>- num_bytes -= recd;
>- } while (retries-- && total < max);
>-
>- tpm_buf_destroy(&buf);
>-
>- return total ? total : -EIO;
>-out:
>- tpm_buf_destroy(&buf);
>- tpm2_end_auth_session(chip);
>- return err;
>-}
>-
> /**
> * tpm2_flush_context() - execute a TPM2_FlushContext command
> * @chip: TPM chip to use
>--
>2.39.5
>
>
J.
--
] https://www.earth.li/~noodles/ [] Generally, all generalizations [
] PGP/GPG Key @ the.earth.li [] are false.. [
] via keyserver, web or email. [] [
] RSA: 4096/0x94FA372B2DA8B985 [] [
On Fri, Dec 19, 2025 at 09:43:27AM +0000, Jonathan McDowell wrote: > On Tue, Dec 16, 2025 at 11:21:37AM +0200, Jarkko Sakkinen wrote: > > tpm1_get_random() and tpm2_get_random() contain duplicate orchestration > > code. Consolidate orchestration to tpm_get_random(). > > Does keeping the respective tpm1/tpm2 bits in their -cmd.c files not make > more sense, still allowing for the consolidation of orchestration in > tpm_get_random? Yeah, especially after not paying attention to this for couple of weeks this really feels like unnecessary. It would also reduce the overall delta caused by these patches. I will take here step back and retain the helpers in tpm1/tpm2-cmd.c files. BR, Jarkko
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