Guilherme G. Piccoli c6ce163bb8 firmware: google: Test spinlock on panic path to avoid lockups ... [ Upstream commit 3e081438b8 ] 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: 74c5b31c66 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-10-24 09:57:57 +02:00
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coreboot_table.c	bus: Make remove callback return void	2021-07-21 11:53:42 +02:00
coreboot_table.h	firmware: google: make coreboot driver's remove callback return void	2021-02-09 12:12:43 +01:00
framebuffer-coreboot.c	firmware: google: make coreboot driver's remove callback return void	2021-02-09 12:12:43 +01:00
gsmi.c	firmware: google: Test spinlock on panic path to avoid lockups	2022-10-24 09:57:57 +02:00
Kconfig	firmware: google: Properly state IOMEM dependency	2022-03-18 14:18:15 +01:00
Makefile	firmware: coreboot: Collapse platform drivers into bus core	2018-09-14 15:37:23 +02:00
memconsole-coreboot.c	firmware: google: make coreboot driver's remove callback return void	2021-02-09 12:12:43 +01:00
memconsole-x86-legacy.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 287	2019-06-05 17:36:37 +02:00
memconsole.c	Merge 5.2-rc4 into char-misc-next	2019-06-09 09:11:21 +02:00
memconsole.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 287	2019-06-05 17:36:37 +02:00
vpd.c	firmware: google: make coreboot driver's remove callback return void	2021-02-09 12:12:43 +01:00
vpd_decode.c	firmware: google: increment VPD key_len properly	2019-10-11 08:41:34 +02:00
vpd_decode.h	firmware: google: check if size is valid when decoding VPD data	2019-09-04 13:31:28 +02:00