From patchwork Wed Jun 8 00:45:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ed Swierk X-Patchwork-Id: 631883 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rPVBF1dfxz9t3k for ; Wed, 8 Jun 2016 10:46:45 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=sfs-ml-3.v29.ch3.sourceforge.com) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bARdq-0007Za-IH; Wed, 08 Jun 2016 00:46:42 +0000 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bARdp-0007ZS-Mw for tpmdd-devel@lists.sourceforge.net; Wed, 08 Jun 2016 00:46:41 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of skyportsystems.com designates 209.85.192.173 as permitted sender) client-ip=209.85.192.173; envelope-from=eswierk@skyportsystems.com; helo=mail-pf0-f173.google.com; Received: from mail-pf0-f173.google.com ([209.85.192.173]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1bARdo-0005BW-TN for tpmdd-devel@lists.sourceforge.net; Wed, 08 Jun 2016 00:46:41 +0000 Received: by mail-pf0-f173.google.com with SMTP id 62so82880295pfd.1 for ; Tue, 07 Jun 2016 17:46:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=u5Uhqsor9O4hZHLZwGvID68OqMgCiY1+nxorM2KmAoY=; b=Iy+vOliT6MfzMBP4EQMUEk2IzaA9QAkkAusPEky4NOaZToh49M3tnZVgMu4WHBwSB3 l7NJWKQYF2GqT0LGpJ8/iE5pPjX0SrkHNIqIjCdsa7irSyEF58VgUN4slMfiwyAa+3dp bgRTxwlzV7nepMbE0Xvzk6wIIWaxJ52g95+/5xqF9R9xd1n8tjDy8P9Z9SGrz8cfEqIi mCBp9uKFGezgT1uN4XhND3OdFi91+ohVlyWZJ/YAk5a/5qlbn6xNuokHmxkFdcIPew/A 5F/d4rQroXqLma6Yv6PC/n9L9uswy+ebrtMBnjzxWrL2MiMsENfZhm+KNPpZaJihgqlt FQBg== X-Gm-Message-State: ALyK8tIsL+D/otXe/2heP0HufnwoddmE0DGjqP2gDq3DM1IVvt+D2+p7IK4ULqjUsSNYnqcw X-Received: by 10.98.73.27 with SMTP id w27mr2444830pfa.137.1465346795067; Tue, 07 Jun 2016 17:46:35 -0700 (PDT) Received: from eswierk-sc.localdomain (67-207-112-138.static.wiline.com. [67.207.112.138]) by smtp.gmail.com with ESMTPSA id m1sm29489077pab.46.2016.06.07.17.46.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 07 Jun 2016 17:46:34 -0700 (PDT) From: Ed Swierk To: tpmdd-devel@lists.sourceforge.net Date: Tue, 7 Jun 2016 17:45:40 -0700 Message-Id: <1465346740-60120-5-git-send-email-eswierk@skyportsystems.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1465346740-60120-1-git-send-email-eswierk@skyportsystems.com> References: <1465346740-60120-1-git-send-email-eswierk@skyportsystems.com> X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1bARdo-0005BW-TN Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [tpmdd-devel] [PATCH v4 4/4] tpm_tis: Increase ST19NP18 TPM command duration to avoid chip lockup X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: tpmdd-devel-bounces@lists.sourceforge.net 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 --- drivers/char/tpm/tpm_tis.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index 5c74980..0041622 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -485,6 +485,11 @@ static void tpm_tis_update_timeouts(struct tpm_chip *chip) chip->vendor.timeout_d = TIS_SHORT_TIMEOUT * HZ / 1000; 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; } }