Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751266AbdCQR0I (ORCPT ); Fri, 17 Mar 2017 13:26:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55928 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751122AbdCQR0E (ORCPT ); Fri, 17 Mar 2017 13:26:04 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 09E948050B Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jsnitsel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 09E948050B References: <20170315055738.11088-1-jarkko.sakkinen@iki.fi> <87h92uvtce.fsf@redhat.com> <87fuidx5mt.fsf@redhat.com> <20170316115543.jw23imcvkcriaam5@intel.com> User-agent: mu4e 0.9.19; emacs 25.1.1 From: Jerry Snitselaar To: Jarkko Sakkinen Cc: Jarkko Sakkinen , tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, gang.wei@intel.com, Peter Huewe , Marcel Selhorst , Jason Gunthorpe , open list Subject: Re: [PATCH v3] tpm_crb: request and relinquish locality 0 In-reply-to: <20170316115543.jw23imcvkcriaam5@intel.com> Date: Fri, 17 Mar 2017 10:00:41 -0700 Message-ID: <878to3x2h2.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 17 Mar 2017 17:00:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14277 Lines: 362 Jarkko Sakkinen @ 2017-03-16 11:55 GMT: > On Wed, Mar 15, 2017 at 08:27:54PM -0700, Jerry Snitselaar wrote: >> >> Jerry Snitselaar @ 2017-03-16 02:38 GMT: >> >> > Jarkko Sakkinen @ 2017-03-15 05:57 GMT: >> > >> >> From: Jarkko Sakkinen >> >> >> >> This commit adds support for requesting and relinquishing locality 0 in >> >> tpm_crb for the course of command transmission. >> >> >> >> In order to achieve this, two new callbacks are added to struct >> >> tpm_class_ops: >> >> >> >> - request_locality >> >> - relinquish_locality >> >> >> >> These are called before sending and receiving data from the TPM. We >> >> update also tpm_tis_core to use these callbacks. A small modification to >> >> request_locality() is done so that it returns -EBUSY instead of locality >> >> number when check_locality() fails in order to return something >> >> meaningful to the user space. >> >> >> >> With CRB interface you first set either requestAccess or relinquish bit >> >> from TPM_LOC_CTRL_x register and then wait for locAssigned and >> >> tpmRegValidSts bits to be set in the TPM_LOC_STATE_x register. >> >> >> >> The reason why were are doing this is to make sure that the driver >> >> will work properly with Intel TXT that uses locality 2. There's no >> >> explicit guarantee that it would relinquish this locality. In more >> >> general sense this commit enables tpm_crb to be a well behaving >> >> citizen in a multi locality environment. >> >> >> >> Signed-off-by: Jarkko Sakkinen >> >> --- >> >> v2: >> >> - TPM driver level calllbacks >> >> v3: >> >> - Call ops->relinquish_locality only if ops->request_locality has been >> >> successful. >> >> - Do not reserve locality in nested tpm_transmit calls. >> >> - Check for tpmRegValidSts to make sure that the value in TPM_LOC_STATE_x is >> >> stable. >> >> drivers/char/tpm/tpm-interface.c | 10 ++++++++++ >> >> drivers/char/tpm/tpm.h | 3 ++- >> >> drivers/char/tpm/tpm2-space.c | 15 +++++++++------ >> >> drivers/char/tpm/tpm_crb.c | 41 ++++++++++++++++++++++++++++++++++++++++ >> >> drivers/char/tpm/tpm_tis_core.c | 12 ++++-------- >> >> include/linux/tpm.h | 3 ++- >> >> 6 files changed, 68 insertions(+), 16 deletions(-) >> >> >> >> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c >> >> index 95c6f98..4cd216f 100644 >> >> --- a/drivers/char/tpm/tpm-interface.c >> >> +++ b/drivers/char/tpm/tpm-interface.c >> >> @@ -384,6 +384,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, >> >> ssize_t len = 0; >> >> u32 count, ordinal; >> >> unsigned long stop; >> >> + bool no_locality = !(flags & TPM_TRANSMIT_HAS_LOCALITY); >> >> >> >> if (!tpm_validate_command(chip, buf, bufsiz)) >> >> return -EINVAL; >> >> @@ -407,6 +408,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, >> >> if (chip->dev.parent) >> >> pm_runtime_get_sync(chip->dev.parent); >> >> >> >> + if (no_locality && chip->ops->request_locality) { >> >> + rc = chip->ops->request_locality(chip, 0); >> >> + if (rc) >> >> + goto out_no_locality; >> >> + } >> >> + >> >> rc = tpm2_prepare_space(chip, space, ordinal, buf); >> >> if (rc) >> >> goto out; >> >> @@ -466,6 +473,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, >> >> rc = tpm2_commit_space(chip, space, ordinal, buf, &len); >> >> >> >> out: >> >> + if (no_locality && chip->ops->relinquish_locality) >> >> + chip->ops->relinquish_locality(chip, 0, false); >> >> +out_no_locality: >> >> if (chip->dev.parent) >> >> pm_runtime_put_sync(chip->dev.parent); >> >> >> >> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h >> >> index 5eacb3f..ba2c00d 100644 >> >> --- a/drivers/char/tpm/tpm.h >> >> +++ b/drivers/char/tpm/tpm.h >> >> @@ -521,7 +521,8 @@ extern const struct file_operations tpmrm_fops; >> >> extern struct idr dev_nums_idr; >> >> >> >> enum tpm_transmit_flags { >> >> - TPM_TRANSMIT_UNLOCKED = BIT(0), >> >> + TPM_TRANSMIT_UNLOCKED = BIT(0), >> >> + TPM_TRANSMIT_HAS_LOCALITY = BIT(1), >> >> }; >> >> >> >> ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, >> >> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c >> >> index d36d81e..43d05ab 100644 >> >> --- a/drivers/char/tpm/tpm2-space.c >> >> +++ b/drivers/char/tpm/tpm2-space.c >> >> @@ -19,6 +19,9 @@ >> >> #include >> >> #include "tpm.h" >> >> >> >> +#define TPM_TRANSMIT_NESTED \ >> >> + (TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_HAS_LOCALITY) >> >> + >> >> enum tpm2_handle_types { >> >> TPM2_HT_HMAC_SESSION = 0x02000000, >> >> TPM2_HT_POLICY_SESSION = 0x03000000, >> >> @@ -39,7 +42,7 @@ static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space) >> >> for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) { >> >> if (space->session_tbl[i]) >> >> tpm2_flush_context_cmd(chip, space->session_tbl[i], >> >> - TPM_TRANSMIT_UNLOCKED); >> >> + TPM_TRANSMIT_NESTED); >> >> } >> >> } >> >> >> >> @@ -84,7 +87,7 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, >> >> tpm_buf_append(&tbuf, &buf[*offset], body_size); >> >> >> >> rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 4, >> >> - TPM_TRANSMIT_UNLOCKED, NULL); >> >> + TPM_TRANSMIT_NESTED, NULL); >> >> if (rc < 0) { >> >> dev_warn(&chip->dev, "%s: failed with a system error %d\n", >> >> __func__, rc); >> >> @@ -132,7 +135,7 @@ static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, >> >> tpm_buf_append_u32(&tbuf, handle); >> >> >> >> rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 0, >> >> - TPM_TRANSMIT_UNLOCKED, NULL); >> >> + TPM_TRANSMIT_NESTED, NULL); >> >> if (rc < 0) { >> >> dev_warn(&chip->dev, "%s: failed with a system error %d\n", >> >> __func__, rc); >> >> @@ -169,7 +172,7 @@ static void tpm2_flush_space(struct tpm_chip *chip) >> >> for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) >> >> if (space->context_tbl[i] && ~space->context_tbl[i]) >> >> tpm2_flush_context_cmd(chip, space->context_tbl[i], >> >> - TPM_TRANSMIT_UNLOCKED); >> >> + TPM_TRANSMIT_NESTED); >> >> >> >> tpm2_flush_sessions(chip, space); >> >> } >> >> @@ -376,7 +379,7 @@ static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp, >> >> >> >> return 0; >> >> out_no_slots: >> >> - tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_UNLOCKED); >> >> + tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_NESTED); >> >> dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__, >> >> phandle); >> >> return -ENOMEM; >> >> @@ -468,7 +471,7 @@ static int tpm2_save_space(struct tpm_chip *chip) >> >> return rc; >> >> >> >> tpm2_flush_context_cmd(chip, space->context_tbl[i], >> >> - TPM_TRANSMIT_UNLOCKED); >> >> + TPM_TRANSMIT_NESTED); >> >> space->context_tbl[i] = ~0; >> >> } >> >> >> >> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c >> >> index 1dfc37e..eb2fcf1 100644 >> >> --- a/drivers/char/tpm/tpm_crb.c >> >> +++ b/drivers/char/tpm/tpm_crb.c >> >> @@ -34,6 +34,16 @@ enum crb_defaults { >> >> CRB_ACPI_START_INDEX = 1, >> >> }; >> >> >> >> +enum crb_loc_ctrl { >> >> + CRB_LOC_CTRL_REQUEST_ACCESS = BIT(0), >> >> + CRB_LOC_CTRL_RELINQUISH = BIT(1), >> >> +}; >> >> + >> >> +enum crb_loc_state { >> >> + CRB_LOC_STATE_LOC_ASSIGNED = BIT(1), >> >> + CRB_LOC_STATE_TPM_REG_VALID_STS = BIT(7), >> >> +}; >> >> + >> >> enum crb_ctrl_req { >> >> CRB_CTRL_REQ_CMD_READY = BIT(0), >> >> CRB_CTRL_REQ_GO_IDLE = BIT(1), >> >> @@ -172,6 +182,35 @@ static int __maybe_unused crb_cmd_ready(struct device *dev, >> >> return 0; >> >> } >> >> >> >> +static int crb_request_locality(struct tpm_chip *chip, int loc) >> >> +{ >> >> + struct crb_priv *priv = dev_get_drvdata(&chip->dev); >> >> + u32 value = CRB_LOC_STATE_LOC_ASSIGNED | >> >> + CRB_LOC_STATE_TPM_REG_VALID_STS; >> >> + >> >> + if (!priv->regs_h) >> >> + return 0; >> >> + >> >> + iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl); >> >> + if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value, >> >> + TPM2_TIMEOUT_C)) { >> >> + dev_warn(&chip->dev, "TPM_LOC_STATE_x.requestAccess timed out\n"); >> >> + return -ETIME; >> >> + } >> >> + >> >> + return 0; >> >> +} >> >> + >> >> +static void crb_relinquish_locality(struct tpm_chip *chip, int loc, bool force) >> >> +{ >> >> + struct crb_priv *priv = dev_get_drvdata(&chip->dev); >> >> + >> >> + if (!priv->regs_h) >> >> + return; >> >> + >> >> + iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl); >> >> +} >> >> + >> >> static u8 crb_status(struct tpm_chip *chip) >> >> { >> >> struct crb_priv *priv = dev_get_drvdata(&chip->dev); >> >> @@ -278,6 +317,8 @@ static const struct tpm_class_ops tpm_crb = { >> >> .send = crb_send, >> >> .cancel = crb_cancel, >> >> .req_canceled = crb_req_canceled, >> >> + .request_locality = crb_request_locality, >> >> + .relinquish_locality = crb_relinquish_locality, >> >> .req_complete_mask = CRB_DRV_STS_COMPLETE, >> >> .req_complete_val = CRB_DRV_STS_COMPLETE, >> >> }; >> >> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c >> >> index fc0e9a2..c3cbe24 100644 >> >> --- a/drivers/char/tpm/tpm_tis_core.c >> >> +++ b/drivers/char/tpm/tpm_tis_core.c >> >> @@ -73,7 +73,7 @@ static int check_locality(struct tpm_chip *chip, int l) >> >> return -1; >> >> } >> >> >> >> -static void release_locality(struct tpm_chip *chip, int l, int force) >> >> +static void release_locality(struct tpm_chip *chip, int l, bool force) >> >> { >> >> struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); >> >> int rc; >> >> @@ -97,7 +97,7 @@ static int request_locality(struct tpm_chip *chip, int l) >> >> long rc; >> >> >> >> if (check_locality(chip, l) >= 0) >> >> - return l; >> >> + return -EBUSY; >> >> >> >> rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE); >> >> if (rc < 0) >> >> @@ -252,7 +252,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) >> >> >> >> out: >> >> tpm_tis_ready(chip); >> >> - release_locality(chip, priv->locality, 0); >> >> return size; >> >> } >> >> >> >> @@ -268,9 +267,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) >> >> size_t count = 0; >> >> bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; >> >> >> >> - if (request_locality(chip, 0) < 0) >> >> - return -EBUSY; >> >> - >> >> status = tpm_tis_status(chip); >> >> if ((status & TPM_STS_COMMAND_READY) == 0) { >> >> tpm_tis_ready(chip); >> >> @@ -329,7 +325,6 @@ static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) >> >> >> >> out_err: >> >> tpm_tis_ready(chip); >> >> - release_locality(chip, priv->locality, 0); >> >> return rc; >> >> } >> >> >> >> @@ -390,7 +385,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len) >> >> return len; >> >> out_err: >> >> tpm_tis_ready(chip); >> >> - release_locality(chip, priv->locality, 0); >> >> return rc; >> >> } >> >> >> >> @@ -681,6 +675,8 @@ static const struct tpm_class_ops tpm_tis = { >> >> .send = tpm_tis_send, >> >> .cancel = tpm_tis_ready, >> >> .update_timeouts = tpm_tis_update_timeouts, >> >> + .request_locality = request_locality, >> >> + .relinquish_locality = release_locality, >> >> .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID, >> >> .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID, >> >> .req_canceled = tpm_tis_req_canceled, >> >> diff --git a/include/linux/tpm.h b/include/linux/tpm.h >> >> index da158f0..65e05f9 100644 >> >> --- a/include/linux/tpm.h >> >> +++ b/include/linux/tpm.h >> >> @@ -48,7 +48,8 @@ struct tpm_class_ops { >> >> u8 (*status) (struct tpm_chip *chip); >> >> bool (*update_timeouts)(struct tpm_chip *chip, >> >> unsigned long *timeout_cap); >> >> - >> >> + int (*request_locality)(struct tpm_chip *chip, int loc); >> >> + void (*relinquish_locality)(struct tpm_chip *chip, int loc, bool force); >> >> }; >> >> >> >> #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE) >> > >> > This is broken for me on tpm_tis at the moment. release_locality only >> > actually follows through with releasing if you've set force or there is >> > a pending request for the TPM from another locality. So first time >> > through it requests and gets the locality, does its work, goes >> > to release it and doesn't because there is no pending request. Then >> > next time through, request_locality calls check_locality and returns >> > -EBUSY causing it to bail out of tpm_transmit. >> >> Actually I should amend that, I'd been debugging a bit. With the >> patch itself, tpm_tis_core_init() calls tpm2_probe() which fails >> because tpm_transmit_cmd -> tpm_transmit -> request_locality returns >> -EBUSY. There is a request_locality() call right before the >> tpm2_probe(). I'd dropped that as part of my debugging which allowed >> it to get further along, but then run into the problem mentioned above. > > I see. > > The request_locality call in tpm_tis_core_init should works with this > change because it does only whether the return value is zero so that > can be safely ignored. > Yes, the request_locality call works there, I just wasn't sure it was necessary since tpm2_probe will end up calling it (and returning -EBUSY). I guess it would be needed prior to the probe_itpm call since nothing in there calls request_locality now. It seems a bit odd that probe_iptm calls release_locality twice though. > The send data case totally breaks. > > Changing the return value to -EBUSY was a stupid mistake from my side. > > I'll try revise this a bit in a way that the API will allow positive > value for stating that the given locality has been already taking. > Is there a big performance hit with requesting and releasing locality? If instead it just released it when release_locality is called I think the changes are pretty minor. > Thank you for catching this up. > > [1] http://lxr.free-electrons.com/source/drivers/char/tpm/tpm_tis_core.c > > /Jarkko