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path: root/drivers/char/tpm/tpm.c
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Diffstat (limited to 'drivers/char/tpm/tpm.c')
-rw-r--r--drivers/char/tpm/tpm.c74
1 files changed, 64 insertions, 10 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 3af9f4d1a23f..f26afdb1a702 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -30,12 +30,7 @@
#include <linux/freezer.h>
#include "tpm.h"
-
-enum tpm_const {
- TPM_MINOR = 224, /* officially assigned */
- TPM_BUFSIZE = 4096,
- TPM_NUM_DEVICES = 256,
-};
+#include "tpm_eventlog.h"
enum tpm_duration {
TPM_SHORT = 0,
@@ -482,6 +477,7 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
#define TPM_INTERNAL_RESULT_SIZE 200
#define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
#define TPM_ORD_GET_CAP cpu_to_be32(101)
+#define TPM_ORD_GET_RANDOM cpu_to_be32(70)
static const struct tpm_input_header tpm_getcap_header = {
.tag = TPM_TAG_RQU_COMMAND,
@@ -919,7 +915,7 @@ EXPORT_SYMBOL_GPL(tpm_show_pcrs);
#define READ_PUBEK_RESULT_SIZE 314
#define TPM_ORD_READPUBEK cpu_to_be32(124)
-struct tpm_input_header tpm_readpubek_header = {
+static struct tpm_input_header tpm_readpubek_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(30),
.ordinal = TPM_ORD_READPUBEK
@@ -1175,7 +1171,7 @@ int tpm_release(struct inode *inode, struct file *file)
flush_work(&chip->work);
file->private_data = NULL;
atomic_set(&chip->data_pending, 0);
- kfree(chip->data_buffer);
+ kzfree(chip->data_buffer);
clear_bit(0, &chip->is_open);
put_device(chip->dev);
return 0;
@@ -1227,7 +1223,6 @@ ssize_t tpm_read(struct file *file, char __user *buf,
del_singleshot_timer_sync(&chip->user_read_timer);
flush_work(&chip->work);
ret_size = atomic_read(&chip->data_pending);
- atomic_set(&chip->data_pending, 0);
if (ret_size > 0) { /* relay data */
ssize_t orig_ret_size = ret_size;
if (size < ret_size)
@@ -1242,6 +1237,8 @@ ssize_t tpm_read(struct file *file, char __user *buf,
mutex_unlock(&chip->buffer_mutex);
}
+ atomic_set(&chip->data_pending, 0);
+
return ret_size;
}
EXPORT_SYMBOL_GPL(tpm_read);
@@ -1326,6 +1323,58 @@ int tpm_pm_resume(struct device *dev)
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
+#define TPM_GETRANDOM_RESULT_SIZE 18
+static struct tpm_input_header tpm_getrandom_header = {
+ .tag = TPM_TAG_RQU_COMMAND,
+ .length = cpu_to_be32(14),
+ .ordinal = TPM_ORD_GET_RANDOM
+};
+
+/**
+ * tpm_get_random() - Get random bytes from the tpm's RNG
+ * @chip_num: A specific chip number for the request or TPM_ANY_NUM
+ * @out: destination buffer for the random bytes
+ * @max: the max number of bytes to write to @out
+ *
+ * Returns < 0 on error and the number of bytes read on success
+ */
+int tpm_get_random(u32 chip_num, u8 *out, size_t max)
+{
+ struct tpm_chip *chip;
+ struct tpm_cmd_t tpm_cmd;
+ u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
+ int err, total = 0, retries = 5;
+ u8 *dest = out;
+
+ chip = tpm_chip_find_get(chip_num);
+ if (chip == NULL)
+ return -ENODEV;
+
+ if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+ return -EINVAL;
+
+ do {
+ tpm_cmd.header.in = tpm_getrandom_header;
+ tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
+
+ err = transmit_cmd(chip, &tpm_cmd,
+ TPM_GETRANDOM_RESULT_SIZE + num_bytes,
+ "attempting get random");
+ if (err)
+ break;
+
+ recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
+ memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
+
+ dest += recd;
+ total += recd;
+ num_bytes -= recd;
+ } while (retries-- && total < max);
+
+ return total ? total : -EIO;
+}
+EXPORT_SYMBOL_GPL(tpm_get_random);
+
/* In case vendor provided release function, call it too.*/
void tpm_dev_vendor_release(struct tpm_chip *chip)
@@ -1346,7 +1395,7 @@ EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
* Once all references to platform device are down to 0,
* release all allocated structures.
*/
-void tpm_dev_release(struct device *dev)
+static void tpm_dev_release(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
@@ -1427,6 +1476,11 @@ struct tpm_chip *tpm_register_hardware(struct device *dev,
goto put_device;
}
+ if (sys_add_ppi(&dev->kobj)) {
+ misc_deregister(&chip->vendor.miscdev);
+ goto put_device;
+ }
+
chip->bios_dir = tpm_bios_log_setup(devname);
/* Make chip available */