Re: [PATCH v7 15/17] tpm: introduce tpm_chip_start() and tpm_chip_stop()

From: Jarkko Sakkinen
Date: Thu Nov 15 2018 - 15:26:22 EST


On Tue, Nov 13, 2018 at 05:34:54PM -0500, 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.
>
>
> [ 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@xxxxxxxxxxxxxxx>
> > ---
> > 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 for the feedback. I'll try to reproduce this myself.

/Jarkko