On 2020/3/4 4:04 下午, Greg Kroah-Hartman wrote:
On Wed, Mar 04, 2020 at 03:44:44PM +0800, Wen Yang wrote:
From: Sai Praneeth sai.praneeth.prakhya@intel.com
[ 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@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 Cc: Sasha Levin sashal@kernel.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: stable@vger.kernel.org
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?
Thank you very much. We hope it could be applied to 4.19.
Best wishes,
-- Wen