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Srinivas Pandruvada bc6ac6c0f6 platform/x86: ISST: Fix possible circular locking dependency detected
[ Upstream commit 17da2d5f93692086dd096a975225ffd5622d0bf8 ]

As reported:

[  256.104522] ======================================================
[  256.113783] WARNING: possible circular locking dependency detected
[  256.120093] 5.16.0-rc6-yocto-standard+ #99 Not tainted
[  256.125362] ------------------------------------------------------
[  256.131673] intel-speed-sel/844 is trying to acquire lock:
[  256.137290] ffffffffc036f0d0 (punit_misc_dev_lock){+.+.}-{3:3}, at: isst_if_open+0x18/0x90 [isst_if_common]
[  256.147171]
[  256.147171] but task is already holding lock:
[  256.153135] ffffffff8ee7cb50 (misc_mtx){+.+.}-{3:3}, at: misc_open+0x2a/0x170
[  256.160407]
[  256.160407] which lock already depends on the new lock.
[  256.160407]
[  256.168712]
[  256.168712] the existing dependency chain (in reverse order) is:
[  256.176327]
[  256.176327] -> #1 (misc_mtx){+.+.}-{3:3}:
[  256.181946]        lock_acquire+0x1e6/0x330
[  256.186265]        __mutex_lock+0x9b/0x9b0
[  256.190497]        mutex_lock_nested+0x1b/0x20
[  256.195075]        misc_register+0x32/0x1a0
[  256.199390]        isst_if_cdev_register+0x65/0x180 [isst_if_common]
[  256.205878]        isst_if_probe+0x144/0x16e [isst_if_mmio]
...
[  256.241976]
[  256.241976] -> #0 (punit_misc_dev_lock){+.+.}-{3:3}:
[  256.248552]        validate_chain+0xbc6/0x1750
[  256.253131]        __lock_acquire+0x88c/0xc10
[  256.257618]        lock_acquire+0x1e6/0x330
[  256.261933]        __mutex_lock+0x9b/0x9b0
[  256.266165]        mutex_lock_nested+0x1b/0x20
[  256.270739]        isst_if_open+0x18/0x90 [isst_if_common]
[  256.276356]        misc_open+0x100/0x170
[  256.280409]        chrdev_open+0xa5/0x1e0
...

The call sequence suggested that misc_device /dev file can be opened
before misc device is yet to be registered, which is done only once.

Here punit_misc_dev_lock was used as common lock, to protect the
registration by multiple ISST HW drivers, one time setup, prevent
duplicate registry of misc device and prevent load/unload when device
is open.

We can split into locks:
- One which just prevent duplicate call to misc_register() and one
time setup. Also never call again if the misc_register() failed or
required one time setup is failed. This lock is not shared with
any misc device callbacks.

- The other lock protects registry, load and unload of HW drivers.

Sequence in isst_if_cdev_register()
- Register callbacks under punit_misc_dev_open_lock
- Call isst_misc_reg() which registers misc_device on the first
registry which is under punit_misc_dev_reg_lock, which is not
shared with callbacks.

Sequence in isst_if_cdev_unregister
Just opposite of isst_if_cdev_register

Reported-and-tested-by: Liwei Song <liwei.song@windriver.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20220112022521.54669-1-srinivas.pandruvada@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-23 11:59:55 +01:00
arch parisc: Drop __init from map_pages declaration 2022-02-23 11:59:54 +01:00
block block: bio-integrity: Advance seed correctly for larger interval sizes 2022-02-08 18:24:28 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:47:29 +02:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-17 09:48:40 +01:00
Documentation bpf: Add kconfig knob for disabling unpriv bpf by default 2022-02-16 12:52:49 +01:00
drivers platform/x86: ISST: Fix possible circular locking dependency detected 2022-02-23 11:59:55 +01:00
fs btrfs: send: in case of IO error log it 2022-02-23 11:59:55 +01:00
include net: fix a memleak when uncloning an skb dst and its metadata 2022-02-16 12:52:51 +01:00
init bpf: Add kconfig knob for disabling unpriv bpf by default 2022-02-16 12:52:49 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:23:35 +01:00
kernel perf: Fix list corruption in perf_cgroup_switch() 2022-02-16 12:52:53 +01:00
lib lib/test_meminit: destroy cache in kmem_cache_alloc_bulk() test 2022-01-27 09:19:55 +01:00
LICENSES
mm mm/kmemleak: avoid scanning potential huge holes 2022-02-08 18:24:28 +01:00
net tipc: rate limit warning for received illegal binding update 2022-02-16 12:52:51 +01:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts Makefile.extrawarn: Move -Wunaligned-access to W=1 2022-02-23 11:59:54 +01:00
security ima: Do not print policy rule with inactive LSM labels 2022-02-16 12:52:47 +01:00
sound ASoC: max9759: fix underflow in speaker_gain_control_put() 2022-02-08 18:24:33 +01:00
tools perf probe: Fix ppc64 'perf probe add events failed' case 2022-02-16 12:52:50 +01:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: do not shrink halt_poll_ns below grow_start 2021-10-09 14:39:50 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
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MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.180 2022-02-16 12:52:54 +01:00
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