diff mbox series

efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Message ID 20230301085545.2373646-1-chenhuacai@loongson.cn
State Accepted
Commit 8364f6d000ede4185a82b1f2514543ed172d4b51
Headers show
Series efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel | expand

Commit Message

Huacai Chen March 1, 2023, 8:55 a.m. UTC
Since Linux-6.3, LoongArch supports PIE kernel now, so let's reintroduce
efi_relocate_kernel() to relocate the core kernel.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 drivers/firmware/efi/libstub/loongarch-stub.c | 24 ++++++-------------
 1 file changed, 7 insertions(+), 17 deletions(-)

Comments

Ard Biesheuvel March 1, 2023, 9:16 a.m. UTC | #1
On Wed, 1 Mar 2023 at 09:55, Huacai Chen <chenhuacai@loongson.cn> wrote:
>
> Since Linux-6.3, LoongArch supports PIE kernel now, so let's reintroduce
> efi_relocate_kernel() to relocate the core kernel.
>

Nice!

I assume you will need to make a similar change for zboot?

> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>  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;
>  }
> --
> 2.39.1
>
Youling Tang March 1, 2023, 9:20 a.m. UTC | #2
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,

--- 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@loongson.cn>
> ---
>  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;
>  }
>
Huacai Chen March 1, 2023, 9:30 a.m. UTC | #3
Hi, Youling,

On Wed, Mar 1, 2023 at 5:21 PM Youling Tang <tangyouling@loongson.cn> 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.

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@loongson.cn>
> > ---
> >  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;
> >  }
> >
>
Huacai Chen March 1, 2023, 9:44 a.m. UTC | #4
Hi, Ard,

On Wed, Mar 1, 2023 at 5:17 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Wed, 1 Mar 2023 at 09:55, Huacai Chen <chenhuacai@loongson.cn> wrote:
> >
> > Since Linux-6.3, LoongArch supports PIE kernel now, so let's reintroduce
> > efi_relocate_kernel() to relocate the core kernel.
> >
>
> Nice!
>
> I assume you will need to make a similar change for zboot?
zboot is always PIE (even before 6.3), so I suppose we don't need to
do anything?

Huacai
>
> > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> > ---
> >  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;
> >  }
> > --
> > 2.39.1
> >
Youling Tang March 1, 2023, 10:07 a.m. UTC | #5
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@loongson.cn> 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

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@loongson.cn>
>>> ---
>>>  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;
>>>  }
>>>
>>
Huacai Chen March 1, 2023, 12:06 p.m. UTC | #6
Hi, Youling,

On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <tangyouling@loongson.cn> 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@loongson.cn> 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@loongson.cn>
> >>> ---
> >>>  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;
> >>>  }
> >>>
> >>
>
>
Huacai Chen April 5, 2023, 8:13 a.m. UTC | #7
Hi, Ard,

What is the status of this patch now?

Huacai

On Wed, Mar 1, 2023 at 8:06 PM Huacai Chen <chenhuacai@kernel.org> wrote:
>
> Hi, Youling,
>
> On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <tangyouling@loongson.cn> 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@loongson.cn> 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@loongson.cn>
> > >>> ---
> > >>>  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;
> > >>>  }
> > >>>
> > >>
> >
> >
Ard Biesheuvel April 5, 2023, 8:19 a.m. UTC | #8
On Wed, 5 Apr 2023 at 10:14, Huacai Chen <chenhuacai@kernel.org> wrote:
>
> Hi, Ard,
>
> What is the status of this patch now?
>

I'd still like to understand how zboot is affected. It has

static unsigned long alloc_preferred_address(unsigned long alloc_size)
{
#ifdef EFI_KIMG_PREFERRED_ADDRESS
        efi_physical_addr_t efi_addr = EFI_KIMG_PREFERRED_ADDRESS;

        if (efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
                        alloc_size / EFI_PAGE_SIZE, &efi_addr) == EFI_SUCCESS)
                return efi_addr;
#endif
        return ULONG_MAX;
}

and if I understand you correctly, we never needed this in the first place?

(I understand this is a separate issue, but it would be nice to get
rid of EFI_KIMG_PREFERRED_ADDRESS entirely if we can.)



> On Wed, Mar 1, 2023 at 8:06 PM Huacai Chen <chenhuacai@kernel.org> wrote:
> >
> > Hi, Youling,
> >
> > On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <tangyouling@loongson.cn> 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@loongson.cn> 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@loongson.cn>
> > > >>> ---
> > > >>>  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;
> > > >>>  }
> > > >>>
> > > >>
> > >
> > >
Huacai Chen April 5, 2023, 9:57 a.m. UTC | #9
Hi, Ard,

On Wed, Apr 5, 2023 at 4:20 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Wed, 5 Apr 2023 at 10:14, Huacai Chen <chenhuacai@kernel.org> wrote:
> >
> > Hi, Ard,
> >
> > What is the status of this patch now?
> >
>
> I'd still like to understand how zboot is affected. It has
>
> static unsigned long alloc_preferred_address(unsigned long alloc_size)
> {
> #ifdef EFI_KIMG_PREFERRED_ADDRESS
>         efi_physical_addr_t efi_addr = EFI_KIMG_PREFERRED_ADDRESS;
>
>         if (efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
>                         alloc_size / EFI_PAGE_SIZE, &efi_addr) == EFI_SUCCESS)
>                 return efi_addr;
> #endif
>         return ULONG_MAX;
> }
>
> and if I understand you correctly, we never needed this in the first place?
Technically we don't need this, but I think setting a preferred
address as before may be better (keeping the default behavior the same
as before can avoid some unexpected problem).

Huacai
>
> (I understand this is a separate issue, but it would be nice to get
> rid of EFI_KIMG_PREFERRED_ADDRESS entirely if we can.)
>
>
>
> > On Wed, Mar 1, 2023 at 8:06 PM Huacai Chen <chenhuacai@kernel.org> wrote:
> > >
> > > Hi, Youling,
> > >
> > > On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <tangyouling@loongson.cn> 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@loongson.cn> 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@loongson.cn>
> > > > >>> ---
> > > > >>>  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;
> > > > >>>  }
> > > > >>>
> > > > >>
> > > >
> > > >
Ard Biesheuvel April 5, 2023, 10:13 a.m. UTC | #10
On Wed, 5 Apr 2023 at 11:57, Huacai Chen <chenhuacai@kernel.org> wrote:
>
> Hi, Ard,
>
> On Wed, Apr 5, 2023 at 4:20 PM Ard Biesheuvel <ardb@kernel.org> wrote:
> >
> > On Wed, 5 Apr 2023 at 10:14, Huacai Chen <chenhuacai@kernel.org> wrote:
> > >
> > > Hi, Ard,
> > >
> > > What is the status of this patch now?
> > >
> >
> > I'd still like to understand how zboot is affected. It has
> >
> > static unsigned long alloc_preferred_address(unsigned long alloc_size)
> > {
> > #ifdef EFI_KIMG_PREFERRED_ADDRESS
> >         efi_physical_addr_t efi_addr = EFI_KIMG_PREFERRED_ADDRESS;
> >
> >         if (efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
> >                         alloc_size / EFI_PAGE_SIZE, &efi_addr) == EFI_SUCCESS)
> >                 return efi_addr;
> > #endif
> >         return ULONG_MAX;
> > }
> >
> > and if I understand you correctly, we never needed this in the first place?
> Technically we don't need this, but I think setting a preferred
> address as before may be better (keeping the default behavior the same
> as before can avoid some unexpected problem).
>

OK makes sense

I have queued this up now, should appear in -next tomorrow.
diff mbox series

Patch

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;
 }