[ 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: NBhupesh Sharma <bhsharma@redhat.com>
Suggested-by: NMatt Fleming <matt@codeblueprint.co.uk>
Based-on-code-from: Ricardo Neri <ricardo.neri@intel.com>
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: 3eb420e7 ("efi: Use a work queue to invoke EFI Runtime Services")
Signed-off-by: NWen Yang <wenyang@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>