Hi, Youling,
On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <tangyouling@xxxxxxxxxxx> wrote:
>
> Hi, Huacai
>
> On 03/01/2023 05:30 PM, Huacai Chen wrote:
> > Hi, Youling,
> >
> > On Wed, Mar 1, 2023 at 5:21 PM Youling Tang <tangyouling@xxxxxxxxxxx> wrote:
> >>
> >> Hi, Huacai
> >>
> >> On 03/01/2023 04:55 PM, Huacai Chen wrote:
> >>> Since Linux-6.3, LoongArch supports PIE kernel now, so let's reintroduce
> >>> efi_relocate_kernel() to relocate the core kernel.
> >>
> >> If we strongly rely on the PIE feature after the modification, we need
> >> to modify it as follows,
> > There is no strong rely, efi_relocate_kernel() can also handle the
> > non-PIE kernel.
>
> IMHO, if EFI_KIMG_PREFERRED_ADDRESS is no longer defined as
> `PHYSADDR(VMLINUX_LOAD_ADDRESS)` (physical link address), we need to
> relocate through the RELOCATABLE function, so it is recommended to
> select RELOCATABLE if EFI_STUB is enabled
We can select RELOCATABLE when we modify EFI_KIMG_PREFERRED_ADDRESS.
Before that I prefer to give a chance to build a non-PIE kernel.
Huacai
>
> Youling.
> >
> > Huacai
> >>
> >> --- a/arch/loongarch/Kconfig
> >> +++ b/arch/loongarch/Kconfig
> >> @@ -137,6 +137,7 @@ config LOONGARCH
> >> select PCI_MSI_ARCH_FALLBACKS
> >> select PCI_QUIRKS
> >> select PERF_USE_VMALLOC
> >> + select RELOCATABLE
> >> select RTC_LIB
> >> select SMP
> >> select SPARSE_IRQ
> >>
> >> or:
> >>
> >> --- a/arch/loongarch/Kconfig
> >> +++ b/arch/loongarch/Kconfig
> >> @@ -360,6 +360,7 @@ config EFI_STUB
> >> default y
> >> depends on EFI
> >> select EFI_GENERIC_STUB
> >> + select RELOCATABLE
> >> help
> >>
> >> Youling.
> >>
> >>>
> >>> Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> >>> ---
> >>> drivers/firmware/efi/libstub/loongarch-stub.c | 24 ++++++-------------
> >>> 1 file changed, 7 insertions(+), 17 deletions(-)
> >>>
> >>> diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c
> >>> index eee7ed43cdfb..72c71ae201f0 100644
> >>> --- a/drivers/firmware/efi/libstub/loongarch-stub.c
> >>> +++ b/drivers/firmware/efi/libstub/loongarch-stub.c
> >>> @@ -21,26 +21,16 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
> >>> efi_loaded_image_t *image,
> >>> efi_handle_t image_handle)
> >>> {
> >>> - int nr_pages = round_up(kernel_asize, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
> >>> - efi_physical_addr_t kernel_addr = EFI_KIMG_PREFERRED_ADDRESS;
> >>> efi_status_t status;
> >>> + unsigned long kernel_addr = 0;
> >>>
> >>> - /*
> >>> - * Allocate space for the kernel image at the preferred offset. This is
> >>> - * the only location in memory from where we can execute the image, so
> >>> - * no point in falling back to another allocation.
> >>> - */
> >>> - status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
> >>> - EFI_LOADER_DATA, nr_pages, &kernel_addr);
> >>> - if (status != EFI_SUCCESS)
> >>> - return status;
> >>> -
> >>> - *image_addr = EFI_KIMG_PREFERRED_ADDRESS;
> >>> - *image_size = kernel_asize;
> >>> + kernel_addr = (unsigned long)&kernel_offset - kernel_offset;
> >>> +
> >>> + status = efi_relocate_kernel(&kernel_addr, kernel_fsize, kernel_asize,
> >>> + EFI_KIMG_PREFERRED_ADDRESS, efi_get_kimg_min_align(), 0x0);
> >>>
> >>> - memcpy((void *)EFI_KIMG_PREFERRED_ADDRESS,
> >>> - (void *)&kernel_offset - kernel_offset,
> >>> - kernel_fsize);
> >>> + *image_addr = kernel_addr;
> >>> + *image_size = kernel_asize;
> >>>
> >>> return status;
> >>> }
> >>>
> >>
>
>
