From: Ed Swierk <eswierk@skyportsystems.com> To: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Cc: jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, stefanb@us.ibm.com, eswierk@skyportsystems.com Subject: [PATCH v8 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Date: Tue, 21 Jun 2016 18:10:31 -0700 [thread overview] Message-ID: <1466557831-113440-6-git-send-email-eswierk@skyportsystems.com> (raw) In-Reply-To: <1466557831-113440-1-git-send-email-eswierk@skyportsystems.com> The STMicro ST19NP18-TPM sometimes takes much longer to execute commands than it reports in its capabilities. For example, command 186 (TPM_FlushSpecific) has been observed to take 14560 msec to complete, far longer than the 3000 msec limit for "short" commands reported by the chip. The behavior has also been seen with command 101 (TPM_GetCapability). Worse, when the tpm_tis driver attempts to cancel the current command (by writing commandReady = 1 to TPM_STS_x), the chip locks up completely, returning all-1s from all memory-mapped register reads. The lockup can be cleared only by resetting the system. The occurrence of this excessive command duration depends on the sequence of commands preceding it. One sequence is creating at least 2 new keys via TPM_CreateWrapKey, then letting the TPM idle for at least 30 seconds, then loading a key via TPM_LoadKey2. The next TPM_FlushSpecific occasionally takes tens of seconds to complete. Another sequence is creating many keys in a row without pause. The TPM_CreateWrapKey operation gets much slower after the first few iterations, as one would expect when the pool of precomputed keys is exhausted. Then after a 35-second pause, the same TPM_LoadKey2 followed by TPM_FlushSpecific sequence triggers the behavior. Our working theory is that this older TPM sometimes pauses to precompute keys, which modern chips implement as a background process. Without access to the chip's implementation details it's impossible to know whether any commands are immune to being blocked by this process. So it seems safest to ignore the chip's reported command durations, and use a value much higher than any observed duration, like 180 sec (which is the duration this chip reports for "long" commands). Signed-off-by: Ed Swierk <eswierk@skyportsystems.com> --- drivers/char/tpm/tpm_tis.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index caf7278..8355b45 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -485,6 +485,12 @@ static void tpm_tis_update_timeouts(struct tpm_chip *chip) chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT); chip->vendor.timeout_adjusted = true; break; + case 0x0000104a: /* STMicro ST19NP18-TPM */ + chip->vendor.duration[TPM_SHORT] = 180 * HZ; + chip->vendor.duration[TPM_MEDIUM] = 180 * HZ; + chip->vendor.duration[TPM_LONG] = 180 * HZ; + chip->vendor.duration_adjusted = true; + break; } } -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Ed Swierk <eswierk-FilZDy9cOaHkQYj/0HfcvtBPR1lH4CV8@public.gmane.org> To: tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [PATCH v8 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Date: Tue, 21 Jun 2016 18:10:31 -0700 [thread overview] Message-ID: <1466557831-113440-6-git-send-email-eswierk@skyportsystems.com> (raw) In-Reply-To: <1466557831-113440-1-git-send-email-eswierk-FilZDy9cOaHkQYj/0HfcvtBPR1lH4CV8@public.gmane.org> The STMicro ST19NP18-TPM sometimes takes much longer to execute commands than it reports in its capabilities. For example, command 186 (TPM_FlushSpecific) has been observed to take 14560 msec to complete, far longer than the 3000 msec limit for "short" commands reported by the chip. The behavior has also been seen with command 101 (TPM_GetCapability). Worse, when the tpm_tis driver attempts to cancel the current command (by writing commandReady = 1 to TPM_STS_x), the chip locks up completely, returning all-1s from all memory-mapped register reads. The lockup can be cleared only by resetting the system. The occurrence of this excessive command duration depends on the sequence of commands preceding it. One sequence is creating at least 2 new keys via TPM_CreateWrapKey, then letting the TPM idle for at least 30 seconds, then loading a key via TPM_LoadKey2. The next TPM_FlushSpecific occasionally takes tens of seconds to complete. Another sequence is creating many keys in a row without pause. The TPM_CreateWrapKey operation gets much slower after the first few iterations, as one would expect when the pool of precomputed keys is exhausted. Then after a 35-second pause, the same TPM_LoadKey2 followed by TPM_FlushSpecific sequence triggers the behavior. Our working theory is that this older TPM sometimes pauses to precompute keys, which modern chips implement as a background process. Without access to the chip's implementation details it's impossible to know whether any commands are immune to being blocked by this process. So it seems safest to ignore the chip's reported command durations, and use a value much higher than any observed duration, like 180 sec (which is the duration this chip reports for "long" commands). Signed-off-by: Ed Swierk <eswierk-FilZDy9cOaHkQYj/0HfcvtBPR1lH4CV8@public.gmane.org> --- drivers/char/tpm/tpm_tis.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index caf7278..8355b45 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -485,6 +485,12 @@ static void tpm_tis_update_timeouts(struct tpm_chip *chip) chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT); chip->vendor.timeout_adjusted = true; break; + case 0x0000104a: /* STMicro ST19NP18-TPM */ + chip->vendor.duration[TPM_SHORT] = 180 * HZ; + chip->vendor.duration[TPM_MEDIUM] = 180 * HZ; + chip->vendor.duration[TPM_LONG] = 180 * HZ; + chip->vendor.duration_adjusted = true; + break; } } -- 1.9.1 ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape
next prev parent reply other threads:[~2016-06-22 1:11 UTC|newest] Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-08 0:45 [PATCH v4 0/4] tpm: Command duration logging and chip-specific override Ed Swierk 2016-06-08 0:45 ` Ed Swierk 2016-06-08 0:45 ` [PATCH v4 1/4] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-06-08 0:45 ` Ed Swierk 2016-06-08 0:45 ` [PATCH v4 2/4] tpm: Add optional logging of TPM command durations Ed Swierk 2016-06-08 0:45 ` Ed Swierk 2016-06-08 0:45 ` [PATCH v4 3/4] tpm: Allow TPM chip drivers to override reported " Ed Swierk 2016-06-08 0:45 ` Ed Swierk 2016-06-08 19:05 ` [tpmdd-devel] " Jason Gunthorpe 2016-06-08 19:05 ` Jason Gunthorpe 2016-06-08 20:41 ` [tpmdd-devel] " Ed Swierk 2016-06-08 0:45 ` [PATCH v4 4/4] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-06-08 0:45 ` Ed Swierk 2016-06-08 23:00 ` [PATCH v5 0/4] tpm: Command duration logging and chip-specific override Ed Swierk 2016-06-08 23:00 ` Ed Swierk 2016-06-08 23:00 ` [PATCH v5 1/4] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-06-08 23:00 ` Ed Swierk 2016-06-08 23:00 ` [PATCH v5 2/4] tpm: Add optional logging of TPM command durations Ed Swierk 2016-06-08 23:00 ` Ed Swierk 2016-06-08 23:00 ` [PATCH v5 3/4] tpm: Allow TPM chip drivers to override reported " Ed Swierk 2016-06-08 23:00 ` Ed Swierk 2016-06-10 12:19 ` Jarkko Sakkinen 2016-06-10 17:34 ` Ed Swierk 2016-06-10 19:42 ` Jarkko Sakkinen 2016-06-10 19:42 ` Jarkko Sakkinen 2016-06-11 1:54 ` Ed Swierk 2016-06-11 1:54 ` Ed Swierk 2016-06-08 23:00 ` [PATCH v5 4/4] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-06-08 23:00 ` Ed Swierk 2016-06-11 1:55 ` [PATCH v6 0/5] tpm: Command duration logging and chip-specific override Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-11 1:55 ` [PATCH v6 1/5] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-11 1:55 ` [PATCH v6 2/5] tpm: Add optional logging of TPM command durations Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-11 1:55 ` [PATCH v6 3/5] tpm: Factor out reading of timeout and duration capabilities Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-16 20:20 ` Jarkko Sakkinen 2016-06-16 20:20 ` Jarkko Sakkinen 2016-06-19 12:12 ` Jarkko Sakkinen 2016-06-19 12:12 ` Jarkko Sakkinen [not found] ` <20160619120157.GA29626-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> 2016-06-21 1:46 ` Ed Swierk 2016-06-11 1:55 ` [PATCH v6 4/5] tpm: Allow TPM chip drivers to override reported command durations Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-16 20:26 ` Jarkko Sakkinen 2016-06-11 1:55 ` [PATCH v6 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-06-11 1:55 ` Ed Swierk 2016-06-21 1:53 ` [PATCH v7 0/5] tpm: Command duration logging and chip-specific override Ed Swierk 2016-06-21 1:53 ` Ed Swierk 2016-06-21 1:53 ` [PATCH v7 1/5] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-06-21 1:53 ` Ed Swierk 2016-06-21 1:53 ` [PATCH v7 2/5] tpm: Add optional logging of TPM command durations Ed Swierk 2016-06-21 1:53 ` Ed Swierk 2016-06-21 1:54 ` [PATCH v7 3/5] tpm: Clean up reading of timeout and duration capabilities Ed Swierk 2016-06-21 1:54 ` Ed Swierk 2016-06-21 20:52 ` Jarkko Sakkinen 2016-06-21 20:52 ` Jarkko Sakkinen 2016-06-22 0:21 ` Ed Swierk 2016-06-22 0:21 ` Ed Swierk 2016-06-22 10:46 ` Jarkko Sakkinen 2016-06-22 10:46 ` Jarkko Sakkinen 2016-06-21 1:54 ` [PATCH v7 4/5] tpm: Allow TPM chip drivers to override reported command durations Ed Swierk 2016-06-21 1:54 ` Ed Swierk 2016-06-21 20:54 ` Jarkko Sakkinen 2016-06-21 20:54 ` Jarkko Sakkinen 2016-06-21 1:54 ` [PATCH v7 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-06-21 1:54 ` Ed Swierk 2016-06-21 20:55 ` Jarkko Sakkinen 2016-06-21 20:55 ` Jarkko Sakkinen 2016-06-22 1:10 ` [PATCH v8 0/5] tpm: Command duration logging and chip-specific override Ed Swierk 2016-06-22 1:10 ` Ed Swierk 2016-06-22 1:10 ` [PATCH v8 1/5] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-06-22 1:10 ` Ed Swierk 2016-06-24 18:25 ` Jason Gunthorpe 2016-06-24 18:25 ` Jason Gunthorpe 2016-06-24 20:21 ` Jarkko Sakkinen 2016-06-24 20:23 ` Jarkko Sakkinen 2016-06-24 20:26 ` Jason Gunthorpe 2016-06-24 20:26 ` Jason Gunthorpe 2016-06-25 15:24 ` Jarkko Sakkinen 2016-06-25 15:24 ` Jarkko Sakkinen 2016-06-25 15:47 ` Jarkko Sakkinen 2016-06-25 15:47 ` Jarkko Sakkinen 2016-06-27 17:55 ` Jason Gunthorpe 2016-06-27 17:55 ` Jason Gunthorpe 2016-06-22 1:10 ` [PATCH v8 2/5] tpm: Add optional logging of TPM command durations Ed Swierk 2016-06-22 1:10 ` Ed Swierk 2016-06-24 18:27 ` Jason Gunthorpe 2016-06-24 18:27 ` Jason Gunthorpe 2016-06-24 20:24 ` Jarkko Sakkinen 2016-06-24 20:24 ` Jarkko Sakkinen 2016-06-22 1:10 ` [PATCH v8 3/5] tpm: Clean up reading of timeout and duration capabilities Ed Swierk 2016-06-22 1:10 ` Ed Swierk 2016-06-22 1:10 ` [PATCH v8 4/5] tpm: Allow TPM chip drivers to override reported command durations Ed Swierk 2016-06-22 1:10 ` Ed Swierk 2016-06-22 1:10 ` Ed Swierk [this message] 2016-06-22 1:10 ` [PATCH v8 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-07-13 16:19 ` [PATCH v9 0/5] tpm: Command duration logging and chip-specific override Ed Swierk 2016-07-13 16:19 ` [PATCH v9 1/5] tpm_tis: Improve reporting of IO errors Ed Swierk 2016-07-13 16:19 ` [PATCH v9 2/5] tpm: Add optional logging of TPM command durations Ed Swierk 2016-07-13 16:19 ` [PATCH v9 3/5] tpm: Clean up reading of timeout and duration capabilities Ed Swierk 2016-07-18 18:15 ` Jarkko Sakkinen 2016-07-18 18:19 ` Jarkko Sakkinen 2016-07-18 18:19 ` Jarkko Sakkinen 2016-07-18 18:20 ` Jarkko Sakkinen 2016-07-18 18:20 ` Jarkko Sakkinen 2016-07-13 16:19 ` [PATCH v9 4/5] tpm: Allow TPM chip drivers to override reported command durations Ed Swierk 2016-07-13 17:04 ` kbuild test robot 2016-07-13 17:04 ` kbuild test robot 2016-07-18 18:40 ` Jarkko Sakkinen 2016-07-18 18:40 ` Jarkko Sakkinen 2016-07-13 16:19 ` [PATCH v9 5/5] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup Ed Swierk 2016-07-13 16:44 ` [PATCH v9 0/5] tpm: Command duration logging and chip-specific override Ed Swierk 2016-07-13 17:36 ` Jason Gunthorpe 2016-07-13 17:36 ` Jason Gunthorpe 2016-07-13 20:00 ` Ed Swierk 2016-07-13 20:00 ` Ed Swierk 2016-07-13 20:58 ` Eric W. Biederman 2016-07-13 20:59 ` Jason Gunthorpe 2016-07-18 18:07 ` Jarkko Sakkinen 2016-07-18 18:07 ` Jarkko Sakkinen
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