[PATCH 3/5 V3] tpm2: add longer timeouts for creation commands.

From: Tomas Winkler
Date: Sat Mar 10 2018 - 10:19:21 EST


TPM2_CC_Create(0x153) and TPM2_CC_CreatePrimary (0x131) involve generation
of crypto keys which can be a computationally intensive task.
The timeout is set to 3min.
Rather than increasing default timeout a new constant is
added, to not stall for too long on regular commands failures.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
V2: Add more explanation to the commit message.
V3: Rename TPM_DURATION_MAX to TPM_NUM_DURATIONS.
drivers/char/tpm/tpm-interface.c | 3 +++
drivers/char/tpm/tpm.h | 28 ++++++++++++++++++----------
drivers/char/tpm/tpm2-cmd.c | 8 +++++---
3 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 402e54252b22..40d1770f6b38 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -421,6 +421,8 @@ int tpm_get_timeouts(struct tpm_chip *chip)
msecs_to_jiffies(TPM2_DURATION_MEDIUM);
chip->duration[TPM_LONG] =
msecs_to_jiffies(TPM2_DURATION_LONG);
+ chip->duration[TPM_LONG_LONG] =
+ msecs_to_jiffies(TPM2_DURATION_LONG_LONG);

chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
@@ -509,6 +511,7 @@ int tpm_get_timeouts(struct tpm_chip *chip)
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
chip->duration[TPM_LONG] =
usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
+ chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */

/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
* value wrong and apparently reports msecs rather than usecs. So we
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 38197a30ad7b..6ab426916800 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -67,7 +67,9 @@ enum tpm_duration {
TPM_SHORT = 0,
TPM_MEDIUM = 1,
TPM_LONG = 2,
+ TPM_LONG_LONG = 3,
TPM_UNDEFINED,
+ TPM_NUM_DURATIONS = TPM_UNDEFINED,
};

#define TPM_WARN_RETRY 0x800
@@ -79,15 +81,20 @@ enum tpm_duration {
#define TPM_HEADER_SIZE 10

enum tpm2_const {
- TPM2_PLATFORM_PCR = 24,
- TPM2_PCR_SELECT_MIN = ((TPM2_PLATFORM_PCR + 7) / 8),
- TPM2_TIMEOUT_A = 750,
- TPM2_TIMEOUT_B = 2000,
- TPM2_TIMEOUT_C = 200,
- TPM2_TIMEOUT_D = 30,
- TPM2_DURATION_SHORT = 20,
- TPM2_DURATION_MEDIUM = 750,
- TPM2_DURATION_LONG = 2000,
+ TPM2_PLATFORM_PCR = 24,
+ TPM2_PCR_SELECT_MIN = ((TPM2_PLATFORM_PCR + 7) / 8),
+};
+
+enum tpm2_timeouts {
+ TPM2_TIMEOUT_A = 750,
+ TPM2_TIMEOUT_B = 2000,
+ TPM2_TIMEOUT_C = 200,
+ TPM2_TIMEOUT_D = 30,
+ TPM2_DURATION_SHORT = 20,
+ TPM2_DURATION_MEDIUM = 750,
+ TPM2_DURATION_LONG = 2000,
+ TPM2_DURATION_LONG_LONG = 300000,
+ TPM2_DURATION_DEFAULT = 120000,
};

enum tpm2_structures {
@@ -123,6 +130,7 @@ enum tpm2_algorithms {

enum tpm2_command_codes {
TPM2_CC_FIRST = 0x011F,
+ TPM2_CC_CREATE_PRIMARY = 0x0131,
TPM2_CC_SELF_TEST = 0x0143,
TPM2_CC_STARTUP = 0x0144,
TPM2_CC_SHUTDOWN = 0x0145,
@@ -227,7 +235,7 @@ struct tpm_chip {
unsigned long timeout_c; /* jiffies */
unsigned long timeout_d; /* jiffies */
bool timeout_adjusted;
- unsigned long duration[3]; /* jiffies */
+ unsigned long duration[TPM_NUM_DURATIONS]; /* jiffies */
bool duration_adjusted;

struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index a700f8f9ead7..c1ddbbba406e 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -90,6 +90,8 @@ static struct tpm2_hash tpm2_hash_map[] = {
* of time the chip could take to return the result. The values
* of the SHORT, MEDIUM, and LONG durations are taken from the
* PC Client Profile (PTP) specification.
+ * LONG_LONG is for commands that generates keys which empirically
+ * takes longer time on some systems.
*/
static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
TPM_UNDEFINED, /* 11F */
@@ -110,7 +112,7 @@ static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
TPM_UNDEFINED, /* 12e */
TPM_UNDEFINED, /* 12f */
TPM_UNDEFINED, /* 130 */
- TPM_UNDEFINED, /* 131 */
+ TPM_LONG_LONG, /* 131 */
TPM_UNDEFINED, /* 132 */
TPM_UNDEFINED, /* 133 */
TPM_UNDEFINED, /* 134 */
@@ -144,7 +146,7 @@ static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
TPM_UNDEFINED, /* 150 */
TPM_UNDEFINED, /* 151 */
TPM_UNDEFINED, /* 152 */
- TPM_UNDEFINED, /* 153 */
+ TPM_LONG_LONG, /* 153 */
TPM_UNDEFINED, /* 154 */
TPM_UNDEFINED, /* 155 */
TPM_UNDEFINED, /* 156 */
@@ -821,7 +823,7 @@ unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
duration = chip->duration[index];

if (duration <= 0)
- duration = 2 * 60 * HZ;
+ duration = msecs_to_jiffies(TPM2_DURATION_DEFAULT);

return duration;
}
--
2.14.3