linux-stable.git/drivers/char, branch linux-5.16.y

virtio_console: eliminate anonymous module_init & module_exit

2022-04-13T18:03:11+00:00

[ Upstream commit fefb8a2a941338d871e2d83fbd65fbfa068857bd ]

Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.

Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.

Example 1: (System.map)
 ffffffff832fc78c t init
 ffffffff832fc79e t init
 ffffffff832fc8f8 t init

Example 2: (initcall_debug log)
 calling  init+0x0/0x12 @ 1
 initcall init+0x0/0x12 returned 0 after 15 usecs
 calling  init+0x0/0x60 @ 1
 initcall init+0x0/0x60 returned 0 after 2 usecs
 calling  init+0x0/0x9a @ 1
 initcall init+0x0/0x9a returned 0 after 74 usecs

Signed-off-by: Randy Dunlap 
Reviewed-by: Amit Shah 
Cc: virtualization@lists.linux-foundation.org
Cc: Arnd Bergmann 
Link: https://lore.kernel.org/r/20220316192010.19001-3-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

hwrng: nomadik - Change clk_disable to clk_disable_unprepare

2022-04-08T12:05:41+00:00

[ Upstream commit 7f0f1f3ef62ed7a40e30aff28115bd94c4211d1d ]

The corresponding API for clk_prepare_enable is clk_disable_unprepare,
other than clk_disable_unprepare.

Fix this by changing clk_disable to clk_disable_unprepare.

Fixes: beca35d05cc2 ("hwrng: nomadik - use clk_prepare_enable()")
Signed-off-by: Miaoqian Lin 
Reviewed-by: Linus Walleij 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: atmel - disable trng on failure path

2022-04-08T12:05:40+00:00

[ Upstream commit a223ea9f89ab960eb254ba78429efd42eaf845eb ]

Call atmel_trng_disable() on failure path of probe.

Fixes: a1fa98d8116f ("hwrng: atmel - disable TRNG during suspend")
Signed-off-by: Claudiu Beznea 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: cavium - HW_RANDOM_CAVIUM should depend on ARCH_THUNDER

2022-04-08T12:05:37+00:00

[ Upstream commit ab7d88549e2f7ae116afd303f32e1950cb790a1d ]

The Cavium ThunderX Random Number Generator is only present on Cavium
ThunderX SoCs, and not available as an independent PCIe endpoint.  Hence
add a dependency on ARCH_THUNDER, to prevent asking the user about this
driver when configuring a kernel without Cavium Thunder SoC  support.

Fixes: cc2f1908c6b8f625 ("hwrng: cavium - Add Cavium HWRNG driver for ThunderX SoC.")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

hwrng: cavium - Check health status while reading random data

2022-04-08T12:05:37+00:00

[ Upstream commit 680efb33546be8960ccbb2f4e0e43034d9c93b30 ]

This RNG device is present on Marvell OcteonTx2 silicons as well and
also provides entropy health status.

HW continuously checks health condition of entropy and reports
faults. Fault is in terms of co-processor cycles since last fault
detected. This doesn't get cleared and only updated when new fault
is detected. Also there are chances of detecting false positives.
So to detect a entropy failure SW has to check if failures are
persistent ie cycles elapsed is frequently updated by HW.

This patch adds support to detect health failures using below algo.
1. Consider any fault detected before 10ms as a false positive and ignore.
   10ms is chosen randomly, no significance.
2. Upon first failure detection make a note of cycles elapsed and when this
   error happened in realtime (cntvct).
3. Upon subsequent failure, check if this is new or a old one by comparing
   current cycles with the ones since last failure. cycles or time since
   last failure is calculated using cycles and time info captured at (2).

HEALTH_CHECK status register is not available to VF, hence had to map
PF registers. Also since cycles are in terms of co-processor cycles,
had to retrieve co-processor clock rate from RST device.

Signed-off-by: Sunil Goutham 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

tpm: fix reference counting for struct tpm_chip

2022-04-08T12:05:19+00:00

commit 7e0438f83dc769465ee663bb5dcf8cc154940712 upstream.

The following sequence of operations results in a refcount warning:

1. Open device /dev/tpmrm.
2. Remove module tpm_tis_spi.
3. Write a TPM command to the file descriptor opened at step 1.

------------[ cut here ]------------
WARNING: CPU: 3 PID: 1161 at lib/refcount.c:25 kobject_get+0xa0/0xa4
refcount_t: addition on 0; use-after-free.
Modules linked in: tpm_tis_spi tpm_tis_core tpm mdio_bcm_unimac brcmfmac
sha256_generic libsha256 sha256_arm hci_uart btbcm bluetooth cfg80211 vc4
brcmutil ecdh_generic ecc snd_soc_core crc32_arm_ce libaes
raspberrypi_hwmon ac97_bus snd_pcm_dmaengine bcm2711_thermal snd_pcm
snd_timer genet snd phy_generic soundcore [last unloaded: spi_bcm2835]
CPU: 3 PID: 1161 Comm: hold_open Not tainted 5.10.0ls-main-dirty #2
Hardware name: BCM2711
[] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[] (show_stack) from [] (dump_stack+0xc4/0xd8)
[] (dump_stack) from [] (__warn+0x104/0x108)
[] (__warn) from [] (warn_slowpath_fmt+0x74/0xb8)
[] (warn_slowpath_fmt) from [] (kobject_get+0xa0/0xa4)
[] (kobject_get) from [] (tpm_try_get_ops+0x14/0x54 [tpm])
[] (tpm_try_get_ops [tpm]) from [] (tpm_common_write+0x38/0x60 [tpm])
[] (tpm_common_write [tpm]) from [] (vfs_write+0xc4/0x3c0)
[] (vfs_write) from [] (ksys_write+0x58/0xcc)
[] (ksys_write) from [] (ret_fast_syscall+0x0/0x4c)
Exception stack(0xc226bfa8 to 0xc226bff0)
bfa0:                   00000000 000105b4 00000003 beafe664 00000014 00000000
bfc0: 00000000 000105b4 000103f8 00000004 00000000 00000000 b6f9c000 beafe684
bfe0: 0000006c beafe648 0001056c b6eb6944
---[ end trace d4b8409def9b8b1f ]---

The reason for this warning is the attempt to get the chip->dev reference
in tpm_common_write() although the reference counter is already zero.

Since commit 8979b02aaf1d ("tpm: Fix reference count to main device") the
extra reference used to prevent a premature zero counter is never taken,
because the required TPM_CHIP_FLAG_TPM2 flag is never set.

Fix this by moving the TPM 2 character device handling from
tpm_chip_alloc() to tpm_add_char_device() which is called at a later point
in time when the flag has been set in case of TPM2.

Commit fdc915f7f719 ("tpm: expose spaces via a device link /dev/tpmrm")
already introduced function tpm_devs_release() to release the extra
reference but did not implement the required put on chip->devs that results
in the call of this function.

Fix this by putting chip->devs in tpm_chip_unregister().

Finally move the new implementation for the TPM 2 handling into a new
function to avoid multiple checks for the TPM_CHIP_FLAG_TPM2 flag in the
good case and error cases.

Cc: stable@vger.kernel.org
Fixes: fdc915f7f719 ("tpm: expose spaces via a device link /dev/tpmrm")
Fixes: 8979b02aaf1d ("tpm: Fix reference count to main device")
Co-developed-by: Jason Gunthorpe 
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Lino Sanfilippo 
Tested-by: Stefan Berger 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

virtio_console: break out of buf poll on remove

2022-04-08T12:05:17+00:00

[ Upstream commit 0e7174b9d5877130fec41fb4a16e0c2ee4958d44 ]

A common pattern for device reset is currently:
vdev->config->reset(vdev);
.. cleanup ..

reset prevents new interrupts from arriving and waits for interrupt
handlers to finish.

However if - as is common - the handler queues a work request which is
flushed during the cleanup stage, we have code adding buffers / trying
to get buffers while device is reset. Not good.

This was reproduced by running
	modprobe virtio_console
	modprobe -r virtio_console
in a loop.

Fix this up by calling virtio_break_device + flush before reset.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1786239
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

tpm: use try_get_ops() in tpm-space.c

2022-03-28T07:59:56+00:00

commit fb5abce6b2bb5cb3d628aaa63fa821da8c4600f9 upstream.

As part of the series conversion to remove nested TPM operations:

https://lore.kernel.org/all/20190205224723.19671-1-jarkko.sakkinen@linux.intel.com/

exposure of the chip->tpm_mutex was removed from much of the upper
level code.  In this conversion, tpm2_del_space() was missed.  This
didn't matter much because it's usually called closely after a
converted operation, so there's only a very tiny race window where the
chip can be removed before the space flushing is done which causes a
NULL deref on the mutex.  However, there are reports of this window
being hit in practice, so fix this by converting tpm2_del_space() to
use tpm_try_get_ops(), which performs all the teardown checks before
acquring the mutex.

Cc: stable@vger.kernel.org # 5.4.x
Signed-off-by: James Bottomley 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

tpm: Fix error handling in async work

2022-03-28T07:59:54+00:00

commit 2e8e4c8f6673247e22efc7985ce5497accd16f88 upstream.

When an invalid (non existing) handle is used in a TPM command,
that uses the resource manager interface (/dev/tpmrm0) the resource
manager tries to load it from its internal cache, but fails and
the tpm_dev_transmit returns an -EINVAL error to the caller.
The existing async handler doesn't handle these error cases
currently and the condition in the poll handler never returns
mask with EPOLLIN set.
The result is that the poll call blocks and the application gets stuck
until the user_read_timer wakes it up after 120 sec.
Change the tpm_dev_async_work function to handle error conditions
returned from tpm_dev_transmit they are also reflected in the poll mask
and a correct error code could passed back to the caller.

Cc: Jarkko Sakkinen 
Cc: Jason Gunthorpe 
Cc: 
Cc: 
Cc: 

Fixes: 9e1b74a63f77 ("tpm: add support for nonblocking operation")
Tested-by: Jarkko Sakkinen
Signed-off-by: Tadeusz Struk 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Cc: Tadeusz Struk 
Signed-off-by: Greg Kroah-Hartman

random: wake up /dev/random writers after zap

2022-02-23T11:05:52+00:00

[ Upstream commit 042e293e16e3aa9794ce60c29f5b7b0c8170f933 ]

When account() is called, and the amount of entropy dips below
random_write_wakeup_bits, we wake up the random writers, so that they
can write some more in. However, the RNDZAPENTCNT/RNDCLEARPOOL ioctl
sets the entropy count to zero -- a potential reduction just like
account() -- but does not unblock writers. This commit adds the missing
logic to that ioctl to unblock waiting writers.

Reviewed-by: Dominik Brodowski 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Sasha Levin