Hi, Ard and Yao,
The logic of this patch seems right, but I see this in arm64 code:
if (image->image_base != _text) {
efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base
has bogus value\n");
image->image_base = _text;
}
Does this mean image_base is unreliable?
The arm64 code is introduced in commit c2136dceba9a329e997ccce3277
("efi/libstub/arm64: Avoid image_base value from efi_loaded_image"),
and I don't know whether LoongArch has similar problems.
Huacai
On Tue, Dec 19, 2023 at 1:36 PM <wangyao@xxxxxxxxxx> wrote:
>
> From: Wang Yao <wangyao@xxxxxxxxxx>
>
> Replace kernel_offset with image_base to positon the image file that has
> been loaded by UEFI or GRUB.
>
> Signed-off-by: Wang Yao <wangyao@xxxxxxxxxx>
> ---
> arch/loongarch/include/asm/efi.h | 2 --
> arch/loongarch/kernel/head.S | 1 -
> arch/loongarch/kernel/image-vars.h | 1 -
> arch/loongarch/kernel/vmlinux.lds.S | 1 -
> drivers/firmware/efi/libstub/loongarch-stub.c | 9 +++++----
> drivers/firmware/efi/libstub/loongarch-stub.h | 4 ++++
> drivers/firmware/efi/libstub/loongarch.c | 6 ++++--
> 7 files changed, 13 insertions(+), 11 deletions(-)
> create mode 100644 drivers/firmware/efi/libstub/loongarch-stub.h
>
> diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/include/asm/efi.h
> index 91d81f9730ab..eddc8e79b3fa 100644
> --- a/arch/loongarch/include/asm/efi.h
> +++ b/arch/loongarch/include/asm/efi.h
> @@ -32,6 +32,4 @@ static inline unsigned long efi_get_kimg_min_align(void)
>
> #define EFI_KIMG_PREFERRED_ADDRESS PHYSADDR(VMLINUX_LOAD_ADDRESS)
>
> -unsigned long kernel_entry_address(unsigned long kernel_addr);
> -
> #endif /* _ASM_LOONGARCH_EFI_H */
> diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
> index 53b883db0786..0ecab4216392 100644
> --- a/arch/loongarch/kernel/head.S
> +++ b/arch/loongarch/kernel/head.S
> @@ -34,7 +34,6 @@ pe_header:
>
> SYM_DATA(kernel_asize, .long _kernel_asize);
> SYM_DATA(kernel_fsize, .long _kernel_fsize);
> -SYM_DATA(kernel_offset, .long _kernel_offset);
>
> #endif
>
> diff --git a/arch/loongarch/kernel/image-vars.h b/arch/loongarch/kernel/image-vars.h
> index 5087416b9678..41ddcf56d21c 100644
> --- a/arch/loongarch/kernel/image-vars.h
> +++ b/arch/loongarch/kernel/image-vars.h
> @@ -11,7 +11,6 @@ __efistub_strcmp = strcmp;
> __efistub_kernel_entry = kernel_entry;
> __efistub_kernel_asize = kernel_asize;
> __efistub_kernel_fsize = kernel_fsize;
> -__efistub_kernel_offset = kernel_offset;
> #if defined(CONFIG_EFI_EARLYCON) || defined(CONFIG_SYSFB)
> __efistub_screen_info = screen_info;
> #endif
> diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S
> index bb2ec86f37a8..a5d0cd2035da 100644
> --- a/arch/loongarch/kernel/vmlinux.lds.S
> +++ b/arch/loongarch/kernel/vmlinux.lds.S
> @@ -143,7 +143,6 @@ SECTIONS
> _kernel_fsize = _edata - _text;
> _kernel_vsize = _end - __initdata_begin;
> _kernel_rsize = _edata - __initdata_begin;
> - _kernel_offset = kernel_offset - _text;
> #endif
>
> .gptab.sdata : {
> diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c
> index d6ec5d4b8dbe..736b6aae323d 100644
> --- a/drivers/firmware/efi/libstub/loongarch-stub.c
> +++ b/drivers/firmware/efi/libstub/loongarch-stub.c
> @@ -8,10 +8,10 @@
> #include <asm/efi.h>
> #include <asm/addrspace.h>
> #include "efistub.h"
> +#include "loongarch-stub.h"
>
> extern int kernel_asize;
> extern int kernel_fsize;
> -extern int kernel_offset;
> extern int kernel_entry;
>
> efi_status_t handle_kernel_image(unsigned long *image_addr,
> @@ -24,7 +24,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> efi_status_t status;
> unsigned long kernel_addr = 0;
>
> - kernel_addr = (unsigned long)&kernel_offset - kernel_offset;
> + kernel_addr = (unsigned long)image->image_base;
>
> status = efi_relocate_kernel(&kernel_addr, kernel_fsize, kernel_asize,
> EFI_KIMG_PREFERRED_ADDRESS, efi_get_kimg_min_align(), 0x0);
> @@ -35,9 +35,10 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> return status;
> }
>
> -unsigned long kernel_entry_address(unsigned long kernel_addr)
> +unsigned long kernel_entry_address(unsigned long kernel_addr,
> + efi_loaded_image_t *image)
> {
> - unsigned long base = (unsigned long)&kernel_offset - kernel_offset;
> + unsigned long base = (unsigned long)image->image_base;
>
> return (unsigned long)&kernel_entry - base + kernel_addr;
> }
> diff --git a/drivers/firmware/efi/libstub/loongarch-stub.h b/drivers/firmware/efi/libstub/loongarch-stub.h
> new file mode 100644
> index 000000000000..cd015955a015
> --- /dev/null
> +++ b/drivers/firmware/efi/libstub/loongarch-stub.h
> @@ -0,0 +1,4 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +unsigned long kernel_entry_address(unsigned long kernel_addr,
> + efi_loaded_image_t *image);
> diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c
> index 0e0aa6cda73f..684c9354637c 100644
> --- a/drivers/firmware/efi/libstub/loongarch.c
> +++ b/drivers/firmware/efi/libstub/loongarch.c
> @@ -8,6 +8,7 @@
> #include <asm/efi.h>
> #include <asm/addrspace.h>
> #include "efistub.h"
> +#include "loongarch-stub.h"
>
> typedef void __noreturn (*kernel_entry_t)(bool efi, unsigned long cmdline,
> unsigned long systab);
> @@ -37,7 +38,8 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
> return EFI_SUCCESS;
> }
>
> -unsigned long __weak kernel_entry_address(unsigned long kernel_addr)
> +unsigned long __weak kernel_entry_address(unsigned long kernel_addr,
> + efi_loaded_image_t *image)
> {
> return *(unsigned long *)(kernel_addr + 8) - VMLINUX_LOAD_ADDRESS + kernel_addr;
> }
> @@ -73,7 +75,7 @@ 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(kernel_addr);
> + real_kernel_entry = (void *)kernel_entry_address(kernel_addr, image);
>
> real_kernel_entry(true, (unsigned long)cmdline_ptr,
> (unsigned long)efi_system_table);
> --
> 2.27.0
>
