[Problem] efi_pstore creates sysfs files when logging kernel messages to NVRAM. Currently, the sysfs files are updated in a workqueue which is registered in a write callback. On the other hand, situations which users need the sysfs files are when they erase entries or oops happen because a system will be down and users can't access to sysfs files in other cases like panic, reboot or emergency_restart. Also, if kernel panics due to a bug of workqueue operations and a write callback of efi_pstore is called in panic case, efi_pstore may fail due to a failure of schedule_work(). And panic_notifier_chain()/emergency_restart() is not kicked if efi_pstore fails. This may cause user's unwanted result. [Patch Description] This patch registers a workqueue updating sysfs entries in cases where users erase entries or oops happen only, and skips it in other cases like panic, reboot or emergency_start. Signed-off-by: Seiji Aguchi <seiji.aguchi@xxxxxxx> --- drivers/firmware/efivars.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index cd16ea6..d5911fd 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -746,7 +746,12 @@ static int efi_pstore_write(enum pstore_type_id type, spin_unlock_irqrestore(&efivars->lock, flags); - schedule_work(&efivar_work); + /* + * The user may want to update sysfs for this write + * when they erase an entry via /dev/pstore or oops happen. + */ + if (!size || reason == KMSG_DUMP_OOPS) + schedule_work(&efivar_work); *id = part; return ret; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
