On Wed, Mar 04, 2020 at 02:35:15PM +0100, Ard Biesheuvel wrote:
> Commit 59f2a619a2db8611 ("efi: Add 'runtime' pointer to struct efi")
> modified the assembler routine called by efi_set_virtual_address_map(),
> to grab the 'runtime' EFI service pointer while running with paging
> disabled (which is tricky to do in C code)
>
> After the change, register %ebx is not restored correctly, resulting
> in all kinds of weird behavior, so fix that.
>
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
(on top of next-20200304)
Thanks for the quick fix!
Guenter
> ---
> arch/x86/platform/efi/efi_stub_32.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/efi/efi_stub_32.S b/arch/x86/platform/efi/efi_stub_32.S
> index 09237236fb25..09ec84f6ef51 100644
> --- a/arch/x86/platform/efi/efi_stub_32.S
> +++ b/arch/x86/platform/efi/efi_stub_32.S
> @@ -54,7 +54,7 @@ SYM_FUNC_START(efi_call_svam)
> orl $0x80000000, %edx
> movl %edx, %cr0
>
> - pop %ebx
> + movl 16(%esp), %ebx
> leave
> ret
> SYM_FUNC_END(efi_call_svam)
> --
> 2.17.1
>
