Quoting Greg Kroah-Hartman (2020-03-17 10:55:13)
From: Sai Praneeth sai.praneeth.prakhya@intel.com
commit 9dbbedaa6171247c4c7c40b83f05b200a117c2e0 upstream.
After the kernel has booted, if any accesses by firmware causes a page fault, the efi page fault handler would freeze efi_rts_wq and schedules a new process. To do this, the efi page fault handler needs efi_rts_work. Hence, make it accessible.
There will be no race conditions in accessing this structure, because all the calls to efi runtime services are already serialized.
Tested-by: Bhupesh Sharma bhsharma@redhat.com Suggested-by: Matt Fleming matt@codeblueprint.co.uk Based-on-code-from: Ricardo Neri ricardo.neri@intel.com Signed-off-by: Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Fixes: 3eb420e70d87 (“efi: Use a work queue to invoke EFI Runtime Services”) Signed-off-by: Wen Yang wenyang@linux.alibaba.com Cc: Caspar Zhang caspar@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
This requires the fix from
commit ef1491e791308317bb9851a0ad380c4a68b58d54 Author: Waiman Long longman@redhat.com Date: Wed Nov 14 09:55:40 2018 -0800
efi: Fix debugobjects warning on 'efi_rts_work'
The following commit:
9dbbedaa6171 ("efi: Make efi_rts_work accessible to efi page fault handler")
converted 'efi_rts_work' from an auto variable to a global variable. However, when submitting the work, INIT_WORK_ONSTACK() was still used, causing the following complaint from debugobjects:
ODEBUG: object 00000000ed27b500 is NOT on stack 00000000c7d38760, but annotated.
Change the macro to just INIT_WORK() to eliminate the warning.
Signed-off-by: Waiman Long longman@redhat.com Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Acked-by: Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: linux-efi@vger.kernel.org Fixes: 9dbbedaa6171 ("efi: Make efi_rts_work accessible to efi page fault handler") Link: http://lkml.kernel.org/r/20181114175544.12860-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar mingo@kernel.org