On Tue, Dec 5, 2023 at 10:17 AM <wangyao@xxxxxxxxxx> wrote:
>
> From: Wang Yao <wangyao@xxxxxxxxxx>
>
> The efi_relocate_kernel() may load the PIE kernel to anywhere, the load
> address may not be equal to link address or EFI_KIMG_PREFERRED_ADDRESS.
>
> Signed-off-by: Wang Yao <wangyao@xxxxxxxxxx>
> ---
>
> v1->v2:
> Use link address that from DOS header to calculate kernel entry,
> corrected by Huacai Chen.
>
> arch/loongarch/include/asm/efi.h | 2 +-
> drivers/firmware/efi/libstub/loongarch-stub.c | 4 ++--
> drivers/firmware/efi/libstub/loongarch.c | 7 ++++---
> 3 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/include/asm/efi.h
> index 091897d40b03..91d81f9730ab 100644
> --- a/arch/loongarch/include/asm/efi.h
> +++ b/arch/loongarch/include/asm/efi.h
> @@ -32,6 +32,6 @@ static inline unsigned long efi_get_kimg_min_align(void)
>
> #define EFI_KIMG_PREFERRED_ADDRESS PHYSADDR(VMLINUX_LOAD_ADDRESS)
>
> -unsigned long kernel_entry_address(void);
> +unsigned long kernel_entry_address(unsigned long kernel_addr);
>
> #endif /* _ASM_LOONGARCH_EFI_H */
> diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c
> index 72c71ae201f0..4d52f1dc5258 100644
> --- a/drivers/firmware/efi/libstub/loongarch-stub.c
> +++ b/drivers/firmware/efi/libstub/loongarch-stub.c
> @@ -35,9 +35,9 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> return status;
> }
>
> -unsigned long kernel_entry_address(void)
> +unsigned long kernel_entry_address(unsigned long kernel_addr)
> {
> unsigned long base = (unsigned long)&kernel_offset - kernel_offset;
>
> - return (unsigned long)&kernel_entry - base + VMLINUX_LOAD_ADDRESS;
> + return (unsigned long)&kernel_entry - base + TO_CACHE(kernel_addr);
> }
> diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c
> index 807cba2693fc..f17f3db55199 100644
> --- a/drivers/firmware/efi/libstub/loongarch.c
> +++ b/drivers/firmware/efi/libstub/loongarch.c
> @@ -37,9 +37,10 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
> return EFI_SUCCESS;
> }
>
> -unsigned long __weak kernel_entry_address(void)
> +unsigned long __weak kernel_entry_address(unsigned long kernel_addr)
> {
> - return *(unsigned long *)(PHYSADDR(VMLINUX_LOAD_ADDRESS) + 8);
> + return *(unsigned long *)(TO_CACHE(kernel_addr) + 8) -
> + VMLINUX_LOAD_ADDRESS + TO_CACHE(kernel_addr);
Now we are in UEFI environment, so the first TO_CACHE can be dropped,
the return value is used for jump to the core kernel, so the second
TO_CACHE should be used.
BTW, do enough tests please. :)
Huacai
> }
>
> efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
> @@ -73,7 +74,7 @@ efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
> csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0);
> csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1);
>
> - real_kernel_entry = (void *)kernel_entry_address();
> + real_kernel_entry = (void *)kernel_entry_address(kernel_addr);
>
> real_kernel_entry(true, (unsigned long)cmdline_ptr,
> (unsigned long)efi_system_table);
> --
> 2.27.0
>
