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author | Guilherme G. Piccoli <gpiccoli@igalia.com> | 2022-09-09 17:07:55 -0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-24 14:59:44 +0200 |
commit | 3e081438b8e639cc76ef1a5ce0c1bd8a154082c7 (patch) | |
tree | 5ea113fbc98d460da5135f911d9c3a9ad8750ab2 /drivers/rapidio/devices/tsi721.c | |
parent | a5ccec12acfaf3a7ebbbeb90555b35b275fce0df (diff) | |
download | linux-3e081438b8e639cc76ef1a5ce0c1bd8a154082c7.tar.bz2 |
firmware: google: Test spinlock on panic path to avoid lockups
Currently the gsmi driver registers a panic notifier as well as
reboot and die notifiers. The callbacks registered are called in
atomic and very limited context - for instance, panic disables
preemption and local IRQs, also all secondary CPUs (not executing
the panic path) are shutdown.
With that said, taking a spinlock in this scenario is a dangerous
invitation for lockup scenarios. So, fix that by checking if the
spinlock is free to acquire in the panic notifier callback - if not,
bail-out and avoid a potential hang.
Fixes: 74c5b31c6618 ("driver: Google EFI SMI")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20220909200755.189679-1-gpiccoli@igalia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rapidio/devices/tsi721.c')
0 files changed, 0 insertions, 0 deletions