Quoting Greg Kroah-Hartman (2020-03-17 10:55:13)
> From: Sai Praneeth <sai.praneeth.prakhya@xxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Suggested-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> Based-on-code-from: Ricardo Neri <ricardo.neri@xxxxxxxxx>
> Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> Fixes: 3eb420e70d87 (“efi: Use a work queue to invoke EFI Runtime Services”)
> Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>
> Cc: Caspar Zhang <caspar@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
This requires the fix from
commit ef1491e791308317bb9851a0ad380c4a68b58d54
Author: Waiman Long <longman@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Acked-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-efi@xxxxxxxxxxxxxxx
Fixes: 9dbbedaa6171 ("efi: Make efi_rts_work accessible to efi page fault handler")
Link: http://lkml.kernel.org/r/20181114175544.12860-2-ard.biesheuvel@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
