Messages in this thread | | | From | Seiji Aguchi <> | Subject | [RFC][PATCH 0/2] make efivars/efi_pstore interrupt-safe | Date | Fri, 17 Aug 2012 19:41:18 +0000 |
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[Problem] There are following problems related to an interrupt context in efivar/efi_pstore.
Currently, efivars enables interrupt while taking efivars->lock. So, there is a risk to be deadlocking in a write callback of efi_pstore if kernel panics in interrupt context while taking efi_lock.
Also, efi_pstore creates sysfs entries ,which enable users to access to NVRAM, in a write callback. If a kernel panic happens in interrupt contexts, pstore may fail because it could sleep due to dynamic memory allocations during creating sysfs entries.
To resolve the problems above, a goal of this patchset is making efivars/efi_pstore interrupt-safe.
[Patch Description] Patch 1/2 efivars: Disable external interrupt while holding efivars->lock This patch replaces spin_lock/spin_unlock with spin_lock_irqsave/spin_lock_irqrestore to make efivars interrupt safe
Patch 2/2 efi_pstore: Introducing workqueue updating sysfs entries This patch removes sysfs operations from write callback by introducing a workqueue updating sysfs entries
drivers/firmware/efivars.c | 193 +++++++++++++++++++++++++++++++++++--------- include/linux/efi.h | 6 +- 2 files changed, 161 insertions(+), 38 deletions(-)
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