Message-ID: <20181116123130.GB6445@linux.intel.com>
Date:   Fri, 16 Nov 2018 14:32:09 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Stefan Berger <stefanb@...ux.ibm.com>
Cc:     linux-integrity@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        James Bottomley <James.Bottomley@...senPartnership.com>,
        Tomas Winkler <tomas.winkler@...el.com>,
        Tadeusz Struk <tadeusz.struk@...el.com>,
        Stefan Berger <stefanb@...ux.vnet.ibm.com>,
        Nayna Jain <nayna@...ux.ibm.com>,
        Peter Huewe <peterhuewe@....de>,
        Jason Gunthorpe <jgg@...pe.ca>, Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v7 15/17] tpm: introduce tpm_chip_start() and
 tpm_chip_stop()

On Tue, Nov 13, 2018 at 08:56:51PM -0500, Stefan Berger wrote:
> On 11/13/18 5:34 PM, Stefan Berger wrote:
> > On 11/13/18 1:36 PM, Jarkko Sakkinen wrote:
> > > Encapsulate power gating and locality functionality to tpm_chip_start()
> > > and tpm_chip_stop() in order to clean up the branching mess in
> > > tpm_transmit().
> > 
> > 
> > I ran the vtpm proxy test suite on this series and got this error when
> > running it with 'make check-j5'
> > (https://github.com/stefanberger/linux-vtpm-tests).
> > 
> > It's was actually difficult to hit this bug since I ran it with -j1 ,
> > -j2 and so on before.
> 
> This is the diff against your nested branch that fixes this bug and the
> other issue I found:
> 
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 46aa68756bac..42bce9bc41b1 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -155,7 +155,13 @@ int tpm_try_get_ops(struct tpm_chip *chip)
>          goto out_lock;
> 
>      mutex_lock(&chip->tpm_mutex);
> -    return tpm_chip_start(chip);
> +    rc = tpm_chip_start(chip);
> +    if (rc)
> +        goto out_unlock;
> +    return 0;
> +
> +out_unlock:
> +    mutex_unlock(&chip->tpm_mutex);
>  out_lock:
>      up_read(&chip->ops_sem);
>      put_device(&chip->dev);
> diff --git a/drivers/char/tpm/tpm-interface.c
> b/drivers/char/tpm/tpm-interface.c
> index 5e3d5e95ea46..c3260ae8aca3 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -167,6 +167,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf,
> size_t bufsiz)
>      for (;;) {
>          ret = tpm_try_transmit(chip, buf, bufsiz);
> 
> +        if (ret < 0)
> +            break;
>          rc = be32_to_cpu(header->return_code);
>          if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
>              break;
> 
> 
> 
> 
> 
> > 
> > 
> > [ 3003.838138] BUG: unable to handle kernel NULL pointer dereference at
> > 0000000000000000
> > [ 3003.838806] PGD 0 P4D 0
> > [ 3003.838806] Oops: 0010 [#1] SMP PTI
> > [ 3003.840394] CPU: 3 PID: 111 Comm: kworker/3:1 Not tainted 4.20.0-rc2+
> > #6
> > [ 3003.840394] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> > BIOS rel-1.11.0-50-g14221cd-dirty-20181018_164544-sbct-4.pok.ibm.com
> > 04/01/2014
> > [ 3003.840394] Workqueue: tpm-vtpm vtpm_proxy_work
> > [ 3003.840394] RIP: 0010:          (null)
> > [ 3003.840394] Code: Bad RIP value.
> > [ 3003.840394] RSP: 0018:ffffa6e6816d7e10 EFLAGS: 00010246
> > [ 3003.840394] RAX: 00000000ffffffe0 RBX: ffff9698077ad000 RCX:
> > 0000000000000006
> > [ 3003.840394] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> > ffff9698077ad000
> > [ 3003.840394] RBP: ffff9698077ad000 R08: fffff59bc6172d08 R09:
> > 0000000000000000
> > [ 3003.840394] R10: 0000000000000000 R11: 0000000000000000 R12:
> > ffff9698b78f0700
> > [ 3003.840394] R13: ffff9698b78fbc00 R14: 0000000000000000 R15:
> > ffff9697f8ea10f8
> > [ 3003.840394] FS:  0000000000000000(0000) GS:ffff9698b78c0000(0000)
> > knlGS:0000000000000000
> > [ 3003.840394] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 3003.840394] CR2: ffffffffffffffd6 CR3: 0000000190606000 CR4:
> > 00000000000006e0
> > [ 3003.840394] Call Trace:
> > [ 3003.840394]  ? tpm_chip_start+0xb8/0xe0
> > [ 3003.840394]  ? tpm_chip_register+0x15/0x240
> > [ 3003.840394]  ? vtpm_proxy_work+0x15/0x30
> > [ 3003.840394]  ? process_one_work+0x237/0x5c0
> > [ 3003.840394]  ? worker_thread+0x1d5/0x390
> > [ 3003.840394]  ? process_one_work+0x5c0/0x5c0
> > [ 3003.840394]  ? kthread+0x11e/0x140
> > [ 3003.840394]  ? kthread_park+0x90/0x90
> > [ 3003.840394]  ? ret_from_fork+0x3a/0x50
> > [ 3003.840394] Modules linked in: xt_CHECKSUM ipt_MASQUERADE tun
> > nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_rpfilter
> > ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat
> > ebtable_broute bridge stp llc ip6table_nat nf_nat_ipv6 ip6table_mangle
> > ip6table_raw ip6table_security iptable_nat nf_nat_ipv4 nf_nat
> > nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_mangle
> > iptable_raw iptable_security ebtable_filter ebtables ip6table_filter
> > ip6_tables sunrpc virtio_gpu ttm drm_kms_helper drm joydev syscopyarea
> > sysfillrect sysimgblt pcspkr virtio_balloon i2c_piix4 fb_sys_fops
> > virtio_net net_failover virtio_console failover virtio_blk crc32c_intel
> > virtio_pci serio_raw ata_generic virtio_ring virtio pata_acpi floppy
> > qemu_fw_cfg
> > [ 3003.840394] CR2: 0000000000000000
> > [ 3003.840394] ---[ end trace 29e5990b605a7ccb ]---
> > [ 3003.840394] RIP: 0010:          (null)
> > [ 3003.840394] Code: Bad RIP value.
> > [ 3003.840394] RSP: 0018:ffffa6e6816d7e10 EFLAGS: 00010246
> > [ 3003.840394] RAX: 00000000ffffffe0 RBX: ffff9698077ad000 RCX:
> > 0000000000000006
> > [ 3003.840394] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> > ffff9698077ad000
> > [ 3003.840394] RBP: ffff9698077ad000 R08: fffff59bc6172d08 R09:
> > 0000000000000000
> > [ 3003.840394] R10: 0000000000000000 R11: 0000000000000000 R12:
> > ffff9698b78f0700
> > [ 3003.840394] R13: ffff9698b78fbc00 R14: 0000000000000000 R15:
> > ffff9697f8ea10f8
> > [ 3003.840394] FS:  0000000000000000(0000) GS:ffff9698b78c0000(0000)
> > knlGS:0000000000000000
> > [ 3003.840394] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 3003.840394] CR2: ffffffffffffffd6 CR3: 0000000190606000 CR4:
> > 00000000000006e0
> > [ 3003.840394] BUG: sleeping function called from invalid context at
> > ./include/linux/percpu-rwsem.h:34
> > [ 3003.840394] in_atomic(): 0, irqs_disabled(): 1, pid: 111, name:
> > kworker/3:1
> > [ 3003.840394] INFO: lockdep is turned off.
> > [ 3003.840394] irq event stamp: 165206
> > [ 3003.840394] hardirqs last  enabled at (165205): [<ffffffff8b220113>]
> > free_unref_page+0xf3/0x1f0
> > [ 3003.840394] hardirqs last disabled at (165206): [<ffffffff8b0019ee>]
> > trace_hardirqs_off_thunk+0x1a/0x1c
> > [ 3003.840394] softirqs last  enabled at (165182): [<ffffffff8b785e01>]
> > peernet2id+0x41/0x50
> > [ 3003.840394] softirqs last disabled at (165180): [<ffffffff8b785de2>]
> > peernet2id+0x22/0x50
> > [ 3003.840394] CPU: 3 PID: 111 Comm: kworker/3:1 Tainted: G D          
> > 4.20.0-rc2+ #6
> > [ 3003.840394] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> > BIOS rel-1.11.0-50-g14221cd-dirty-20181018_164544-sbct-4.pok.ibm.com
> > 04/01/2014
> > [ 3003.840394] Workqueue: tpm-vtpm vtpm_proxy_work
> > [ 3003.840394] Call Trace:
> > [ 3003.840394]  dump_stack+0x67/0x9b
> > [ 3003.840394]  ___might_sleep+0x149/0x230
> > [ 3003.840394]  exit_signals+0x20/0x210
> > [ 3003.840394]  ? worker_thread+0x1d5/0x390
> > [ 3003.840394]  do_exit+0xa0/0xc70
> > [ 3003.840394]  ? process_one_work+0x5c0/0x5c0
> > [ 3003.840394]  ? kthread+0x11e/0x140
> > [ 3003.840394]  rewind_stack_do_exit+0x17/0x20
> > [ 3004.389582] tpm tpm1803: tpm_try_transmit: tpm_send: error -14
> > 
> > 
> > > 
> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
> > > ---
> > >   drivers/char/tpm/tpm-chip.c      | 110 +++++++++++++++++++++++++++++++
> > >   drivers/char/tpm/tpm-interface.c |  87 +-----------------------
> > >   drivers/char/tpm/tpm.h           |   2 +
> > >   3 files changed, 115 insertions(+), 84 deletions(-)
> > > 
> > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > > index 157505b0f755..65f1561eba81 100644
> > > --- a/drivers/char/tpm/tpm-chip.c
> > > +++ b/drivers/char/tpm/tpm-chip.c
> > > @@ -37,6 +37,116 @@ struct class *tpm_class;
> > >   struct class *tpmrm_class;
> > >   dev_t tpm_devt;
> > > 
> > > +static int tpm_request_locality(struct tpm_chip *chip, unsigned int
> > > flags)
> > > +{
> > > +    int rc;
> > > +
> > > +    if (flags & TPM_TRANSMIT_NESTED)
> > > +        return 0;
> > > +
> > > +    if (!chip->ops->request_locality)
> > > +        return 0;
> > > +
> > > +    rc = chip->ops->request_locality(chip, 0);
> > > +    if (rc < 0)
> > > +        return rc;
> > > +
> > > +    chip->locality = rc;
> > > +    return 0;
> > > +}
> > > +
> > > +static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned
> > > int flags)
> > > +{
> > > +    int rc;
> > > +
> > > +    if (flags & TPM_TRANSMIT_NESTED)
> > > +        return;
> > > +
> > > +    if (!chip->ops->relinquish_locality)
> > > +        return;
> > > +
> > > +    rc = chip->ops->relinquish_locality(chip, chip->locality);
> > > +    if (rc)
> > > +        dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
> > > +
> > > +    chip->locality = -1;
> > > +}
> > > +
> > > +static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
> > > +{
> > > +    if (flags & TPM_TRANSMIT_NESTED)
> > > +        return 0;
> > > +
> > > +    if (!chip->ops->cmd_ready)
> > > +        return 0;
> > > +
> > > +    return chip->ops->cmd_ready(chip);
> > > +}
> > > +
> > > +static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
> > > +{
> > > +    if (flags & TPM_TRANSMIT_NESTED)
> > > +        return 0;
> > > +
> > > +    if (!chip->ops->go_idle)
> > > +        return 0;
> > > +
> > > +    return chip->ops->go_idle(chip);
> > > +}
> > > +
> > > +/**
> > > + * tpm_chip_start() - power on the TPM
> > > + * @chip:    a TPM chip to use
> > > + * @flags:    TPM transmit flags
> > > + *
> > > + * Return:
> > > + * * The response length    - OK
> > > + * * -errno            - A system error
> > > + */
> > > +int tpm_chip_start(struct tpm_chip *chip, unsigned int flags)
> > > +{
> > > +    int ret;
> > > +
> > > +    if (chip->ops->clk_enable)
> > > +        chip->ops->clk_enable(chip, true);
> > > +
> > > +    if (chip->locality == -1) {
> > > +        ret = tpm_request_locality(chip, flags);
> > > +        if (ret) {
> > > +            chip->ops->clk_enable(chip, false);
> > > +            return ret;
> > > +        }
> > > +    }
> > > +
> > > +    ret = tpm_cmd_ready(chip, flags);
> > > +    if (ret) {
> > > +        tpm_relinquish_locality(chip, flags);
> > > +        if (chip->ops->clk_enable)
> > > +            chip->ops->clk_enable(chip, false);
> > > +        return ret;
> > > +    }
> > > +
> > > +    return 0;
> > > +}
> > > +
> > > +/**
> > > + * tpm_chip_stop() - power off the TPM
> > > + * @chip:    a TPM chip to use
> > > + * @flags:    TPM transmit flags
> > > + *
> > > + * Return:
> > > + * * The response length    - OK
> > > + * * -errno            - A system error
> > > + */
> > > +void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags)
> > > +{
> > > +    tpm_go_idle(chip, flags);
> > > +    tpm_relinquish_locality(chip, flags);
> > > +    if (chip->ops->clk_enable)
> > > +        chip->ops->clk_enable(chip, false);
> > > +}
> > > +
> > > +
> > >   /**
> > >    * tpm_try_get_ops() - Get a ref to the tpm_chip
> > >    * @chip: Chip to ref
> > > diff --git a/drivers/char/tpm/tpm-interface.c
> > > b/drivers/char/tpm/tpm-interface.c
> > > index 5865b9671d20..888c9923fca1 100644
> > > --- a/drivers/char/tpm/tpm-interface.c
> > > +++ b/drivers/char/tpm/tpm-interface.c
> > > @@ -62,64 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct
> > > tpm_chip *chip, u32 ordinal)
> > >   }
> > >   EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
> > > 
> > > -static int tpm_request_locality(struct tpm_chip *chip, unsigned int
> > > flags)
> > > -{
> > > -    int rc;
> > > -
> > > -    if (flags & TPM_TRANSMIT_NESTED)
> > > -        return 0;
> > > -
> > > -    if (!chip->ops->request_locality)
> > > -        return 0;
> > > -
> > > -    rc = chip->ops->request_locality(chip, 0);
> > > -    if (rc < 0)
> > > -        return rc;
> > > -
> > > -    chip->locality = rc;
> > > -
> > > -    return 0;
> > > -}
> > > -
> > > -static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned
> > > int flags)
> > > -{
> > > -    int rc;
> > > -
> > > -    if (flags & TPM_TRANSMIT_NESTED)
> > > -        return;
> > > -
> > > -    if (!chip->ops->relinquish_locality)
> > > -        return;
> > > -
> > > -    rc = chip->ops->relinquish_locality(chip, chip->locality);
> > > -    if (rc)
> > > -        dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
> > > -
> > > -    chip->locality = -1;
> > > -}
> > > -
> > > -static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
> > > -{
> > > -    if (flags & TPM_TRANSMIT_NESTED)
> > > -        return 0;
> > > -
> > > -    if (!chip->ops->cmd_ready)
> > > -        return 0;
> > > -
> > > -    return chip->ops->cmd_ready(chip);
> > > -}
> > > -
> > > -static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
> > > -{
> > > -    if (flags & TPM_TRANSMIT_NESTED)
> > > -        return 0;
> > > -
> > > -    if (!chip->ops->go_idle)
> > > -        return 0;
> > > -
> > > -    return chip->ops->go_idle(chip);
> > > -}
> > > -
> > >   static ssize_t tpm_try_transmit(struct tpm_chip *chip, u8 *buf,
> > > size_t bufsiz,
> > >                   unsigned int flags)
> > >   {
> > > @@ -212,7 +154,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8
> > > *buf, size_t bufsiz,
> > >       /* space for header and handles */
> > >       u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
> > >       unsigned int delay_msec = TPM2_DURATION_SHORT;
> > > -    bool has_locality = false;
> > >       u32 rc = 0;
> > >       ssize_t ret;
> > >       const size_t save_size = min(sizeof(save), bufsiz);
> > > @@ -227,34 +168,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8
> > > *buf, size_t bufsiz,
> > >       memcpy(save, buf, save_size);
> > > 
> > >       for (;;) {
> > > -        if (chip->ops->clk_enable != NULL)
> > > -            chip->ops->clk_enable(chip, true);
> > > -
> > > -        if (chip->locality == -1) {
> > > -            ret = tpm_request_locality(chip, flags);
> > > -            if (ret)
> > > -                goto out_locality;
> > > -            has_locality = true;
> > > -        }
> > > -
> > > -        ret = tpm_cmd_ready(chip, flags);
> > > +        ret = tpm_chip_start(chip, flags);
> > >           if (ret)
> > > -            goto out_locality;
> > > -
> > > +            return ret;
> > >           ret = tpm_try_transmit(chip, buf, bufsiz, flags);
> > > +        tpm_chip_stop(chip, flags);
> > > 
> > > -        /* This may fail but do not override ret. */
> > > -        tpm_go_idle(chip, flags);
> > > -
> > > -out_locality:
> > > -        if (has_locality)
> > > -            tpm_relinquish_locality(chip, flags);
> > > -
> > > -        if (chip->ops->clk_enable != NULL)
> > > -            chip->ops->clk_enable(chip, false);
> > > -
> > > -        if (ret < 0)
> > > -            break;
> > >           rc = be32_to_cpu(header->return_code);
> > >           if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
> > >               break;
> > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > > index c7c06de651a0..c42a75710b70 100644
> > > --- a/drivers/char/tpm/tpm.h
> > > +++ b/drivers/char/tpm/tpm.h
> > > @@ -523,6 +523,8 @@ static inline void tpm_msleep(unsigned int
> > > delay_msec)
> > >                delay_msec * 1000);
> > >   };
> > > 
> > > +int tpm_chip_start(struct tpm_chip *chip, unsigned int flags);
> > > +void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags);
> > >   struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);
> > >   __must_check int tpm_try_get_ops(struct tpm_chip *chip);
> > >   void tpm_put_ops(struct tpm_chip *chip);
> > 
> > 
> 

Thank you!

/Jarkko

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