From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: efi: provide empty efi_enter_virtual_mode implementation When CONFIG_EFI is not enabled, we might get an undefined reference to efi_enter_virtual_mode() error, if this efi_enabled() call isn't inlined into start_kernel(). This happens in particular, if start_kernel() is annodated with __no_sanitize_address. Link: http://lkml.kernel.org/r/6514652d3a32d3ed33d6eb5c91d0af63bf0d1a0c.1596544734.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Elena Petrova <lenaptr@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Walter Wu <walter-zh.wu@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/efi.h | 4 ++++ 1 file changed, 4 insertions(+) --- a/include/linux/efi.h~efi-provide-empty-efi_enter_virtual_mode-implementation +++ a/include/linux/efi.h @@ -606,7 +606,11 @@ extern void *efi_get_pal_addr (void); extern void efi_map_pal_code (void); extern void efi_memmap_walk (efi_freemem_callback_t callback, void *arg); extern void efi_gettimeofday (struct timespec64 *ts); +#ifdef CONFIG_EFI extern void efi_enter_virtual_mode (void); /* switch EFI to virtual mode, if possible */ +#else +static inline void efi_enter_virtual_mode (void) {} +#endif #ifdef CONFIG_X86 extern efi_status_t efi_query_variable_store(u32 attributes, unsigned long size, _
