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Manivannan Sadhasivam 7746f3bb89 bus: mhi: host: pci_generic: Use pci_try_reset_function() to avoid deadlock 
commit a321d163de upstream.

There are multiple places from where the recovery work gets scheduled
asynchronously. Also, there are multiple places where the caller waits
synchronously for the recovery to be completed. One such place is during
the PM shutdown() callback.

If the device is not alive during recovery_work, it will try to reset the
device using pci_reset_function(). This function internally will take the
device_lock() first before resetting the device. By this time, if the lock
has already been acquired, then recovery_work will get stalled while
waiting for the lock. And if the lock was already acquired by the caller
which waits for the recovery_work to be completed, it will lead to
deadlock.

This is what happened on the X1E80100 CRD device when the device died
before shutdown() callback. Driver core calls the driver's shutdown()
callback while holding the device_lock() leading to deadlock.

And this deadlock scenario can occur on other paths as well, like during
the PM suspend() callback, where the driver core would hold the
device_lock() before calling driver's suspend() callback. And if the
recovery_work was already started, it could lead to deadlock. This is also
observed on the X1E80100 CRD.

So to fix both issues, use pci_try_reset_function() in recovery_work. This
function first checks for the availability of the device_lock() before
trying to reset the device. If the lock is available, it will acquire it
and reset the device. Otherwise, it will return -EAGAIN. If that happens,
recovery_work will fail with the error message "Recovery failed" as not
much could be done.

Cc: stable@vger.kernel.org # 5.12
Reported-by: Johan Hovold <johan@kernel.org>
Closes: https://lore.kernel.org/mhi/Z1me8iaK7cwgjL92@hovoldconsulting.com
Fixes: 7389337f0a ("mhi: pci_generic: Add suspend/resume/recovery procedure")
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Analyzed-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/mhi/Z2KKjWY2mPen6GPL@hovoldconsulting.com/
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/20250108-mhi_recovery_fix-v1-1-a0a00a17da46@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-03-13 12:51:10 +01:00
arch x86/sgx: Fix size overflows in sgx_encl_create() 2025-03-13 12:51:06 +01:00
block block: fix conversion of GPT partition name to 7-bit 2025-03-13 12:51:03 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: testmgr - some more fixes to RSA test vectors 2025-03-13 12:50:48 +01:00
Documentation kfence: allow use of a deferrable timer 2025-03-13 12:50:49 +01:00
drivers bus: mhi: host: pci_generic: Use pci_try_reset_function() to avoid deadlock 2025-03-13 12:51:10 +01:00
fs Squashfs: check the inode number is not the invalid value of zero 2025-03-13 12:51:09 +01:00
include vmlinux.lds: Ensure that const vars with relocations are mapped R/O 2025-03-13 12:51:00 +01:00
init initramfs: avoid filename buffer overrun 2024-12-14 19:50:42 +01:00
io_uring io_uring: fix possible deadlock in io_register_iowq_max_workers() 2024-11-17 15:06:25 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel sched/fair: Fix potential memory corruption in child_cfs_rq_on_list 2025-03-13 12:51:07 +01:00
lib kfence: allow use of a deferrable timer 2025-03-13 12:50:49 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm: don't skip arch_sync_kernel_mappings() in error paths 2025-03-13 12:51:03 +01:00
net net: ipv6: fix missing dst ref drop in ila lwtunnel 2025-03-13 12:51:07 +01:00
samples samples/landlock: Fix possible NULL dereference in parse_path() 2025-03-13 12:49:57 +01:00
scripts kbuild: Move -Wenum-enum-conversion to W=2 2025-03-13 12:50:29 +01:00
security tomoyo: don't emit warning in tomoyo_write_control() 2025-03-13 12:50:18 +01:00
sound ALSA: usx2y: validate nrpacks module parameter on probe 2025-03-13 12:51:05 +01:00
tools selftests: rtnetlink: update netdevsim ipsec output format 2025-03-13 12:50:46 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 2024-10-22 15:40:41 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Remove *.orig pattern from .gitignore 2024-10-17 15:11:10 +02:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS trace: Relocate event helper files 2024-04-10 16:19:24 +02:00
Makefile Linux 5.15.178 2025-02-01 18:24:02 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.