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Date:   Wed, 3 Feb 2021 02:07:07 +0200
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Lukasz Majczak <lma@semihalf.com>
Cc:     Guenter Roeck <linux@roeck-us.net>,
        James Bottomley <James.Bottomley@hansenpartnership.com>,
        Dirk Gouders <dirk@gouders.net>, Tj <ml.linux@elloe.vision>,
        Peter Huewe <peterhuewe@gmx.de>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        Radoslaw Biernacki <rad@semihalf.com>,
        Marcin Wojtas <mw@semihalf.com>,
        Alex Levin <levinale@google.com>
Subject: Re: [PATCH v3] tpm_tis: Add missing tpm_request/relinquish_locality
 calls
Message-ID: <YBnpK/ceo/WD8/vS@kernel.org>
References: <20210128130753.1283534-1-lma@semihalf.com>
 <20210202155139.521421-1-lma@semihalf.com>
 <YBnI1xHb1Iv6ZlFj@kernel.org>
 <YBnouh06dZZ6vHty@kernel.org>
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On Wed, Feb 03, 2021 at 02:05:17AM +0200, Jarkko Sakkinen wrote:
> On Tue, Feb 02, 2021 at 11:49:11PM +0200, Jarkko Sakkinen wrote:
> > On Tue, Feb 02, 2021 at 04:51:39PM +0100, Lukasz Majczak wrote:
> > > There are missing calls to tpm_request_locality before the calls to
> > > the tpm_get_timeouts() and tpm_tis_probe_irq_single() - both functions
> > > internally send commands to the tpm. As the current
> > > approach might work for tpm2, it fails for tpm1.x - in that case
> > > call to tpm_get_timeouts() or tpm_tis_probe_irq_single()
> > > without acquired locality fails and in turn causes tpm_tis_core_init()
> > > to fail, it can be observed in the log with the following warning
> > > trace:
> > 
> > I said earlier about proper capitalizations of the acronyms.
> > 
> > E.g. "tpm1.x" has no meaning. TPM 1.x has. There's also a few other
> > similar examples.
> > 
> > > 
> > > [    4.324298] TPM returned invalid status
> > > [    4.324806] WARNING: CPU: 2 PID: 1 at drivers/char/tpm/tpm_tis_core.c:275 tpm_tis_status+0x86/0x8f
> > 
> > To make the commit message shorter you could snip from here.
> > 
> > > [    4.325888] Modules linked in:
> > > [    4.326287] CPU: 2 PID: 1 Comm: swapper/0 Tainted: G        W         5.11.0-rc6-next-20210201-00003-g214461adb2e8 #43
> > > [    4.327406] Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.430.0 07/20/2018
> > > [    4.327918] RIP: 0010:tpm_tis_status+0x86/0x8f
> > > [    4.328323] Code: 28 00 00 00 48 3b 45 f0 75 24 89 d8 48 83 c4 10 5b 5d c3 c6 05 58 d9 28 01 01 31 db 48 c7 c7 73 52 98 9c 31 c0 e8 c2 17 b0 ff <0f> 0b eb cd e8 cf 4f 55 00 0f 1f 44 00 00 55 48 89 e56
> > > [    4.330592] RSP: 0000:ffff88810092f7a0 EFLAGS: 00010246
> > > [    4.331223] RAX: 691ee151166db100 RBX: 0000000000000000 RCX: 0000000000000001
> > > [    4.331860] RDX: 0000000000000006 RSI: ffffffff9c96d302 RDI: 00000000ffffffff
> > > [    4.332272] RBP: ffff88810092f7b8 R08: dffffc0000000000 R09: fffffbfff39c96ce
> > > [    4.332683] R10: fffffbfff39c96ce R11: 0000000000000001 R12: ffff8881053e2000
> > > [    4.333109] R13: 0000000065000000 R14: ffff888105d71000 R15: ffff888105cd2628
> > > [    4.333738] FS:  0000000000000000(0000) GS:ffff88842f200000(0000) knlGS:0000000000000000
> > > [    4.334432] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > > [    4.334783] CR2: 0000000000000000 CR3: 0000000037828001 CR4: 00000000003706e0
> > > [    4.335196] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > > [    4.335886] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > > [    4.336793] Call Trace:
> > > [    4.337107]  tpm_tis_send_data+0x3d/0x22f
> > > [    4.337506]  tpm_tis_send_main+0x30/0xf5
> > > [    4.337746]  tpm_transmit+0xbf/0x327
> > > [    4.338042]  ? __alloc_pages_nodemask+0x261/0x36d
> > > [    4.338615]  tpm_transmit_cmd+0x2c/0x93
> > > [    4.339109]  tpm1_getcap+0x232/0x285
> > > [    4.339578]  tpm1_get_timeouts+0x48/0x47d
> > > [    4.339964]  ? lockdep_init_map_type+0x71/0x257
> > > [    4.340256]  ? lockdep_init_map_type+0x71/0x257
> > > [    4.340719]  ? __raw_spin_lock_init+0x40/0x69
> > > [    4.341208]  tpm_tis_core_init+0x402/0x5ee
> > > [    4.341629]  tpm_tis_init+0x11d/0x1a2
> > > [    4.341867]  tpm_tis_pnp_init+0x91/0xb5
> > > [    4.342101]  ? tis_int_handler+0x15f/0x15f
> > > [    4.342466]  pnp_device_probe+0x79/0x9f
> > > [    4.342941]  really_probe+0x149/0x4a8
> > > [    4.343412]  driver_probe_device+0xd6/0x144
> > > [    4.343968]  device_driver_attach+0x42/0x5b
> > > [    4.344382]  __driver_attach+0xca/0x139
> > > [    4.344617]  ? driver_attach+0x1f/0x1f
> > > [    4.344860]  bus_for_each_dev+0x85/0xb7
> > > [    4.345096]  bus_add_driver+0x12b/0x228
> > > [    4.345330]  driver_register+0x64/0xed
> > > [    4.345560]  init_tis+0xa5/0xeb
> > > [    4.345784]  ? lock_is_held_type+0x100/0x141
> > > [    4.346044]  ? tpm_init+0x106/0x106
> > > [    4.346259]  ? rcu_read_lock_sched_held+0x41/0x7e
> > > [    4.346542]  ? tpm_init+0x106/0x106
> > > [    4.346678] battery: ACPI: Battery Slot [BAT0] (battery present)
> > > [    4.346754]  do_one_initcall+0x1b9/0x43d
> > > [    4.346776]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
> > > [    4.347659]  ? lockdep_hardirqs_on+0x8e/0x12e
> > > [    4.347937]  ? lock_is_held_type+0x100/0x141
> > > [    4.348196]  ? rcu_read_lock_sched_held+0x41/0x7e
> > > [    4.348477]  do_initcall_level+0x99/0xa9
> > > [    4.348717]  ? kernel_init+0xe/0x10a
> > > [    4.348954]  do_initcalls+0x4e/0x79
> > > [    4.349170]  kernel_init_freeable+0x15a/0x1ae
> > > [    4.349434]  ? rest_init+0x1d6/0x1d6
> > > [    4.349655]  kernel_init+0xe/0x10a
> > > [    4.349882]  ret_from_fork+0x22/0x30
> > > [    4.350103] irq event stamp: 700039
> > > [    4.350318] hardirqs last  enabled at (700047): [<ffffffff9b735265>] console_unlock+0x4be/0x538
> > > [    4.350836] hardirqs last disabled at (700056): [<ffffffff9b734e84>] console_unlock+0xdd/0x538
> > > [    4.351331] softirqs last  enabled at (699522): [<ffffffff9c4004ec>] __do_softirq+0x4ec/0x539
> > > [    4.351835] softirqs last disabled at (699517): [<ffffffff9c200f62>] asm_call_irq_on_stack+0x12/0x20
> > > 
> > > Following the trace one can also notice a comment in the tpm_tis_status():
> > > 
> > > 		/*
> > > 		 * If this trips, the chances are the read is
> > > 		 * returning 0xff because the locality hasn't been
> > > 		 * acquired.  Usually because tpm_try_get_ops() hasn't
> > > 		 * been called before doing a TPM operation.
> > > 		 */
> > > In this case we don't have to call tpm_try_get_ops()
> > 
> > Do not use "we". Write in imperative term.
> > 
> > > as both calls (tpm_get_timeouts() and tpm_tis_probe_irq_single()) are
> > > in the tpm_tis_core_init function and don't require any locking or clock 
> > > enablement. Similar usage is in the probe_itpm() function also called
> > > inside tpm_tis_core_init().
> > 
> > You use parentheses incosistently here. E.g. tpm_tis_core_init has them
> > in some sentences, and in some it doesn't.
> > 
> > > Tested on Samsung Chromebook Pro (Caroline).
> > > 
> > > Signed-off-by: Lukasz Majczak <lma@semihalf.com>
> > > ---
> > > Hi Jarkko
> > > 
> > > I have checked the linux-next with James patches, also followed Dirk
> > > suggestion applying remaining ones, although without any luck -
> > > a warning trace was still present. As Guneter mentioned earlier, this
> > > patch[1] doesn't address a lack of acquired locality in the
> > > tpm_get_timeouts() and does it only for tpm_tis_probe_irq_single() but
> > > also without a call to tpm_relinquish_locality().
> > > 
> > > Here are my logs from the clean linux-next master branch [2]
> > > (with two James' patches present) and with my
> > > patch applied[3]
> > > 
> > > Best regards,
> > > Lukasz
> > 
> > Ok. Please also take care fixing the cosmetic things, which you
> > clearly haven't done (like writing acronyms correctly).
> > 
> > > [1] https://lore.kernel.org/linux-integrity/20201001180925.13808-5-James.Bottomley@HansenPartnership.com/
> > > [2] https://gist.github.com/semihalf-majczak-lukasz/f588c0684a6cc7d983bb9c4eb4bda586
> > > [3] https://gist.github.com/semihalf-majczak-lukasz/88ede933bc7d28d806e3532850a04054
> > > 
> > > v2 -> v3:
> > >  - Added braces around if part of if/else statements
> > >  - Rebased to linux-next
> > >  - Updated commit message
> > >  
> > >  drivers/char/tpm/tpm-chip.c      |  4 ++--
> > >  drivers/char/tpm/tpm-interface.c | 13 ++++++++++---
> > >  drivers/char/tpm/tpm.h           |  2 ++
> > >  drivers/char/tpm/tpm_tis_core.c  | 14 +++++++++++---
> > >  4 files changed, 25 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > > index ddaeceb7e109..5351963a4b19 100644
> > > --- a/drivers/char/tpm/tpm-chip.c
> > > +++ b/drivers/char/tpm/tpm-chip.c
> > > @@ -32,7 +32,7 @@ struct class *tpm_class;
> > >  struct class *tpmrm_class;
> > >  dev_t tpm_devt;
> > >  
> > > -static int tpm_request_locality(struct tpm_chip *chip)
> > > +int tpm_request_locality(struct tpm_chip *chip)
> > >  {
> > >  	int rc;
> > >  
> > > @@ -47,7 +47,7 @@ static int tpm_request_locality(struct tpm_chip *chip)
> > >  	return 0;
> > >  }
> > >  
> > > -static void tpm_relinquish_locality(struct tpm_chip *chip)
> > > +void tpm_relinquish_locality(struct tpm_chip *chip)
> > >  {
> > >  	int rc;
> > 
> > You need to export the symbols.
> > 
> > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> > > index 1621ce818705..2a9001d329f2 100644
> > > --- a/drivers/char/tpm/tpm-interface.c
> > > +++ b/drivers/char/tpm/tpm-interface.c
> > > @@ -241,10 +241,17 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> > >  	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
> > >  		return 0;
> > >  
> > > -	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> > > +	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> > >  		return tpm2_get_timeouts(chip);
> > > -	else
> > > -		return tpm1_get_timeouts(chip);
> > > +	} else {
> > > +		ssize_t ret = tpm_request_locality(chip);
> > > +
> > > +		if (ret)
> > > +			return ret;
> > > +		ret = tpm1_get_timeouts(chip);
> > > +		tpm_relinquish_locality(chip);
> > > +		return ret;
> > > +	}
> > >  }
> > >  EXPORT_SYMBOL_GPL(tpm_get_timeouts);
> > >  
> > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > > index 947d1db0a5cc..8c13008437dd 100644
> > > --- a/drivers/char/tpm/tpm.h
> > > +++ b/drivers/char/tpm/tpm.h
> > > @@ -193,6 +193,8 @@ static inline void tpm_msleep(unsigned int delay_msec)
> > >  
> > >  int tpm_chip_start(struct tpm_chip *chip);
> > >  void tpm_chip_stop(struct tpm_chip *chip);
> > > +int tpm_request_locality(struct tpm_chip *chip);
> > > +void tpm_relinquish_locality(struct tpm_chip *chip);
> > >  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);
> > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > > index 431919d5f48a..d4f381d6356e 100644
> > > --- a/drivers/char/tpm/tpm_tis_core.c
> > > +++ b/drivers/char/tpm/tpm_tis_core.c
> > > @@ -708,11 +708,19 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
> > >  	u32 cap2;
> > >  	cap_t cap;
> > >  
> > > -	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> > > +	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> > >  		return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
> > > -	else
> > > -		return tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
> > > +	} else {
> > > +		ssize_t ret = tpm_request_locality(chip);
> > > +
> > > +		if (ret)
> > > +			return ret;
> > > +		ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
> > >  				  0);
> > > +		tpm_relinquish_locality(chip);
> > > +		return ret;
> > > +	}
> > 
> > Why this and nost just call tpm_chip_start()?
> 
> I.e. see tpm2_probe().
> 
> Also, add these  in place:
> 
> Cc: stable@vger.kernel.org
> Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
> 
> Also a minor rant (appericiate the fix a lot in all cases): please hold on
> until there's some window to see your patch. I did not understand the
> reason for all these different versions.
> 
> Also remember the fix the minor glitches in the commit message that I
> pointed out.
> 
> And again, thanks for fixing the issue.

I'll hold on up until I get a new version version before sending my PR
together with two of James' earlier fixes.

/Jarkko