linux/drivers/acpi/apei
Kees Cook ea84b580b9 pstore: Convert buf_lock to semaphore
Instead of running with interrupts disabled, use a semaphore. This should
make it easier for backends that may need to sleep (e.g. EFI) when
performing a write:

|BUG: sleeping function called from invalid context at kernel/sched/completion.c:99
|in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum
|Preemption disabled at:
|[<ffffffff99d60512>] pstore_dump+0x72/0x330
|CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G      D           4.20.0-rc3 #45
|Call Trace:
| dump_stack+0x4f/0x6a
| ___might_sleep.cold.91+0xd3/0xe4
| __might_sleep+0x50/0x90
| wait_for_completion+0x32/0x130
| virt_efi_query_variable_info+0x14e/0x160
| efi_query_variable_store+0x51/0x1a0
| efivar_entry_set_safe+0xa3/0x1b0
| efi_pstore_write+0x109/0x140
| pstore_dump+0x11c/0x330
| kmsg_dump+0xa4/0xd0
| oops_exit+0x22/0x30
...

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: 21b3ddd39f ("efi: Don't use spinlocks for efi vars")
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-03 17:11:02 -08:00
..
apei-base.c ACPI / APEI: Fix leaked resources 2016-03-11 00:13:25 +01:00
apei-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bert.c ACPI: APEI: Fix BERT resources conflict with ACPI NVS area 2017-02-27 22:53:11 +01:00
einj.c ACPI, APEI, EINJ: Subtract any matching Register Region from Trigger resources 2017-08-29 00:32:49 +02:00
erst-dbg.c ACPI: Remove FSF mailing addresses 2015-07-08 02:27:32 +02:00
erst.c pstore: Convert buf_lock to semaphore 2018-12-03 17:11:02 -08:00
ghes.c EDAC, ghes: Remove unused argument to ghes_edac_report_mem_error() 2018-05-12 10:59:15 +02:00
hest.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00