On Wed, Mar 04, 2020 at 03:44:44PM +0800, Wen Yang wrote:
> From: Sai Praneeth <sai.praneeth.prakhya@xxxxxxxxx>
>
> [ Upstream commit 9dbbedaa6171247c4c7c40b83f05b200a117c2e0 ]
>
> 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.
>
> [ Wen: This patch also fixes a memory corruption:
> #define efi_queue_work(_rts, _arg1, _arg2, _arg3, _arg4, _arg5)\
> ({ \
> struct efi_runtime_work efi_rts_work; \
> …
> init_completion(&efi_rts_work.efi_rts_comp); \
> INIT_WORK(&efi_rts_work.work, efi_call_rts); \
> …
>
> efi_rts_work is on the stack, registering it to workqueue will cause
> the following error:
>
> ODEBUG: object (____ptrval____) is on stack (____ptrval____),
> but NOT annotated.
> ------------[ cut here ]------------
> WARNING: CPU: 6 PID: 1 at lib/debugobjects.c:368
> __debug_object_init+0x218/0x538
> Modules linked in:
> CPU: 6 PID: 1 Comm: swapper/0 Tainted: G W 4.19.91 #19
> …
> Call trace:
> __debug_object_init+0x218/0x538
> debug_object_init+0x20/0x28
> __init_work+0x34/0x58
> virt_efi_get_time.part.5+0x6c/0x12c
> virt_efi_get_time+0x4c/0x58
> efi_read_time+0x40/0x9c
> __rtc_read_time+0x50/0x118
> rtc_read_time+0x60/0x1f0
> rtc_hctosys+0x74/0x124
> do_one_initcall+0xac/0x3d4
> kernel_init_freeable+0x49c/0x59c
> kernel_init+0x18/0x110 ]
>
> 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>
> Cc: Sasha Levin <sashal@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/firmware/efi/runtime-wrappers.c | 53 +++++--------------------
> include/linux/efi.h | 36 +++++++++++++++++
> 2 files changed, 45 insertions(+), 44 deletions(-)
What stable tree(s) do you wish to see this patch applied to?
thanks,
greg k-h
