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>
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||
|---|---|---|
| .. | ||
| coreboot_table.c | ||
| coreboot_table.h | ||
| framebuffer-coreboot.c | ||
| gsmi.c | ||
| Kconfig | ||
| Makefile | ||
| memconsole-coreboot.c | ||
| memconsole-x86-legacy.c | ||
| memconsole.c | ||
| memconsole.h | ||
| vpd_decode.c | ||
| vpd_decode.h | ||
| vpd.c | ||