From patchwork Thu Nov 10 15:25:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lino Sanfilippo X-Patchwork-Id: 13038928 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17002C4167E for ; Thu, 10 Nov 2022 15:26:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231519AbiKJP0j (ORCPT ); Thu, 10 Nov 2022 10:26:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231567AbiKJP00 (ORCPT ); Thu, 10 Nov 2022 10:26:26 -0500 Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3F303F06B; Thu, 10 Nov 2022 07:26:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1668093943; bh=4XguBKph++G698gHdOWKE+P4P1KjkhqLb40WCE6oSOk=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=rnUgDcOr9y3FYYOM12hPlWn6Cniki5dElw/ik4Zzeid7UpFtn0wq26zc5OQWlWHab u3i7ZcRA8rZma9XLG2acwJwpMM/kz0cbk3bOoakJMJ4G/H7rw4oTplRrKwuvE0WTwo pVP0bfQZllqPrrOXS0VGBJiM7MaCspgfvSKImRRN/2paoGWPH0eSLuIuw8S7uMfwaP VmE9ijnIuLtGLG4LWIimc7JcfAnUM4izEJSyedgn4Ta53akTQ52bSbo89lJhQx8ut0 9KLZomikbrk3s9BW9WNtRZqFXNtAlhykqJPGhgLPJdtOTXar/mjfzURQgfvDU/uCPz +ci4kk52jWmTg== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from Venus.speedport.ip ([84.162.7.17]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MIdeX-1onO7u0FWv-00Eegq; Thu, 10 Nov 2022 16:25:43 +0100 From: Lino Sanfilippo To: peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca Cc: stefanb@linux.vnet.ibm.com, linux@mniewoehner.de, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, jandryuk@gmail.com, pmenzel@molgen.mpg.de, l.sanfilippo@kunbus.com, LinoSanfilippo@gmx.de, lukas@wunner.de, p.rosenberger@kunbus.com Subject: [PATCH v9 01/12] tpm, tpm_tis: Avoid cache incoherency in test for interrupts Date: Thu, 10 Nov 2022 16:25:22 +0100 Message-Id: <20221110152533.24243-2-LinoSanfilippo@gmx.de> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221110152533.24243-1-LinoSanfilippo@gmx.de> References: <20221110152533.24243-1-LinoSanfilippo@gmx.de> MIME-Version: 1.0 X-Provags-ID: V03:K1:WxTfo7CHv952OlJ1ThoqcQEGG2O7RGYNejZ+VF9r78ydbiJt71A PRMLEYviU+2koO9qHtnzsIdlYyfvC0nBxm8+CijRxCH2RNMcAHZiJYuRQ0DoWiPsvIMjobZ NFr8iPyIF7Sm9gWCnhIAWFpN3YITBeqwxPir9xCrAfxmsS6EK4fnFFvRtlLio0XSmbEXsg2 grDENhve8F+b02nBlDtLA== UI-OutboundReport: notjunk:1;M01:P0:1Lq9YwGGrqs=;HkqIsNV81Qh823MNn9Y67CIzzVl Arp1LApSBsIjVhv/agtGm6HsFG1NHXLBPCivgIQ6VYQQmL7iQoZRXU5tj5u+oe6xfx1iIPMIQ hH8k10lYm1QeU8h4QqNaCJzCbFg7oK2tD09h/9+yndT3P7MJq1Mcgv0kGx97mxJWeovBhGtjO b7AO/YKmGuupE4YfjfYunayWr2IE73Bu457JIfMfGQsUCsxUw1t4a6ZHDLQAp2mqbj6n26sss Mp2HUmmCYzgvNNxqRl4T/g4wT2dakMfNHG+awdoAOLWN17lyhc+SAe5SYV318TZhoTrGx6CPr vwOLU1dCmIkcV1uAGDF9XyAYWx0KATwHcybylAJSchVPSfjJmtMxOPaYzXcewTW3TIybCrnvW oI3yPU4c7B0kXTe+jF/SVZrecdt5uf8txoTyjR7kL19Foq4qtTmYAjSP6nasYThA63icfjATJ VO4PwXMvcoZfIb65MeirV+ZM536sGMopIBVxj7hAaoMCFFSWZGJ39guMunfSpXvQh4nTmnDSq vsjflxUlhAVjuMPHhHBjKVNFjZ3a9YAyu1hMC/Nb+d5wRQW0oY7E/UoJ07epfYifXsj04+CwJ j0FcdLKBZwzdch6F6OrFftAjgR4z0/W8eFV2Qe0jjDRl33lekuB8PnDTN8HCYtl/Y/7cOFtjy qcwJlhMeD/JNo9YkzOSYumpQ9sy5e+0Cia4QnPcQeU7cJWsHPhDFE/4YPJGNfJATrZhhuN7RN OiFIBs4YcPxcpOh4HxGODcImfuVRCOfvaEKGkIjTrdmwLt+FiTD/hXs52vfKK95Rz1FQKe6TM QwDtfq2BjEhGXsedat93i/WIIJtX+ULk0FPR6qSCvytifbqaPq1kTS4vPfaskah0LTQECiFF+ USE2wipPDkQoCSFE+d3Y3reQ7NpXnR4m6lYEBjR7eaYabkZFTPYcuMYFuAaCfWNbA9//Jd3LE L4/rNA== Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Lino Sanfilippo The interrupt handler that sets the boolean variable irq_tested may run on another CPU as the thread that checks irq_tested as part of the irq test in tmp_tis_send(). Since nothing guarantees cache coherency between CPUs for unsynchronized accesses to boolean variables the testing thread might not perceive the value change done in the interrupt handler. Avoid this issue by setting the bit TPM_TIS_IRQ_TESTED in the flags field of the tpm_tis_data struct and by accessing this field with the bit manipulating functions that provide cache coherency. Also convert all other existing sites to use the proper macros when accessing this bitfield. Signed-off-by: Lino Sanfilippo Reviewed-by: Jarkko Sakkinen Tested-by: Michael Niewöhner --- drivers/char/tpm/tpm_tis.c | 2 +- drivers/char/tpm/tpm_tis_core.c | 21 +++++++++++---------- drivers/char/tpm/tpm_tis_core.h | 2 +- 3 files changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index bcff6429e0b4..ce43412eb398 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -226,7 +226,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info) irq = tpm_info->irq; if (itpm || is_itpm(ACPI_COMPANION(dev))) - phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND; + set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags); return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg, ACPI_HANDLE(dev)); diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 757623bacfd5..c0008efb95dc 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -351,7 +351,7 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int rc, status, burstcnt; size_t count = 0; - bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; + bool itpm = test_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags); status = tpm_tis_status(chip); if ((status & TPM_STS_COMMAND_READY) == 0) { @@ -484,7 +484,8 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) int rc, irq; struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); - if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested) + if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || + test_bit(TPM_TIS_IRQ_TESTED, &priv->flags)) return tpm_tis_send_main(chip, buf, len); /* Verify receipt of the expected IRQ */ @@ -494,11 +495,11 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) rc = tpm_tis_send_main(chip, buf, len); priv->irq = irq; chip->flags |= TPM_CHIP_FLAG_IRQ; - if (!priv->irq_tested) + if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags)) tpm_msleep(1); - if (!priv->irq_tested) + if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags)) disable_interrupts(chip); - priv->irq_tested = true; + set_bit(TPM_TIS_IRQ_TESTED, &priv->flags); return rc; } @@ -641,7 +642,7 @@ static int probe_itpm(struct tpm_chip *chip) size_t len = sizeof(cmd_getticks); u16 vendor; - if (priv->flags & TPM_TIS_ITPM_WORKAROUND) + if (test_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags)) return 0; rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor); @@ -661,13 +662,13 @@ static int probe_itpm(struct tpm_chip *chip) tpm_tis_ready(chip); - priv->flags |= TPM_TIS_ITPM_WORKAROUND; + set_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags); rc = tpm_tis_send_data(chip, cmd_getticks, len); if (rc == 0) dev_info(&chip->dev, "Detected an iTPM.\n"); else { - priv->flags &= ~TPM_TIS_ITPM_WORKAROUND; + clear_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags); rc = -EFAULT; } @@ -707,7 +708,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id) if (interrupt == 0) return IRQ_NONE; - priv->irq_tested = true; + set_bit(TPM_TIS_IRQ_TESTED, &priv->flags); if (interrupt & TPM_INTF_DATA_AVAIL_INT) wake_up_interruptible(&priv->read_queue); if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT) @@ -793,7 +794,7 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask, if (rc < 0) return rc; - priv->irq_tested = false; + clear_bit(TPM_TIS_IRQ_TESTED, &priv->flags); /* Generate an interrupt by having the core call through to * tpm_tis_send diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 66a5a13cd1df..695a2516dce0 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -86,13 +86,13 @@ enum tis_defaults { enum tpm_tis_flags { TPM_TIS_ITPM_WORKAROUND = BIT(0), TPM_TIS_INVALID_STATUS = BIT(1), + TPM_TIS_IRQ_TESTED = BIT(2), }; struct tpm_tis_data { u16 manufacturer_id; int locality; int irq; - bool irq_tested; unsigned long flags; void __iomem *ilb_base_addr; u16 clkrun_enabled;