Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Lukasz Majczak <lma@semihalf.com>
To:     Guenter Roeck <linux@roeck-us.net>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        James Bottomley <James.Bottomley@hansenpartnership.com>,
        Dirk Gouders <dirk@gouders.net>
Cc:     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: [PATCH v4] tpm_tis: Add missing tpm_request/relinquish_locality calls
Date:   Tue,  2 Feb 2021 20:57:24 +0100
Message-Id: <20210202195724.628468-1-lma@semihalf.com>
In-Reply-To: <20210202155139.521421-1-lma@semihalf.com>
References: <20210202155139.521421-1-lma@semihalf.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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:

[    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
[    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()
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().
Tested on Samsung Chromebook Pro (Caroline).

Signed-off-by: Lukasz Majczak <lma@semihalf.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
Hi Dirk,

Good catch, thank you.

v3 -> v4:
- Added EXPORT_SYMBOL_GPL for tpm_request_locality/tpm_relinquish_locality

 drivers/char/tpm/tpm-chip.c      |  6 ++++--
 drivers/char/tpm/tpm-interface.c | 13 ++++++++++---
 drivers/char/tpm/tpm.h           |  2 ++
 drivers/char/tpm/tpm_tis_core.c  | 14 +++++++++++---
 4 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index ddaeceb7e109..ce9c2650fbe5 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;
 
@@ -46,8 +46,9 @@ static int tpm_request_locality(struct tpm_chip *chip)
 	chip->locality = rc;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tpm_request_locality);
 
-static void tpm_relinquish_locality(struct tpm_chip *chip)
+void tpm_relinquish_locality(struct tpm_chip *chip)
 {
 	int rc;
 
@@ -60,6 +61,7 @@ static void tpm_relinquish_locality(struct tpm_chip *chip)
 
 	chip->locality = -1;
 }
+EXPORT_SYMBOL_GPL(tpm_relinquish_locality);
 
 static int tpm_cmd_ready(struct tpm_chip *chip)
 {
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;
+	}
+
 }
 
 /* Register the IRQ and issue a command that will cause an interrupt. If an
-- 
2.25.1