efi/libstub: Synchronize instruction cache after kernel relocation

The relocated kernel image is copied to its new location using memcpy().
On architectures with separate instruction and data caches, the copied
instructions may remain stale in the instruction cache, leading to the
execution of outdated contents.

Call efi_cache_sync_image() after the relocation copy to ensure the
instruction cache is synchronized with the updated memory contents before
control is transferred to the relocated kernel.

Signed-off-by: WANG Rui <r@hev.cc>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c
index 8c538a5243d9231242254ee2007cebcec9565693..c87ac70251076ceb6db447e9824552626596ebf1 100644 (file)
--- a/drivers/firmware/efi/libstub/loongarch-stub.c
+++ b/drivers/firmware/efi/libstub/loongarch-stub.c
@@ -86,6 +86,7 @@ efi_status_t efi_relocate_kernel(unsigned long *image_addr,
         * have been allocated by UEFI, so we can safely use memcpy.
         */
        memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
+       efi_cache_sync_image(new_addr, image_size);
 
        /* Return the new address of the relocated image. */
        *image_addr = new_addr;