2023-03-01 08:56:02

by Huacai Chen

[permalink] [raw]
Subject: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

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 <[email protected]>
---
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



2023-03-01 09:17:08

by Ard Biesheuvel

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

On Wed, 1 Mar 2023 at 09:55, Huacai Chen <[email protected]> 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 <[email protected]>
> ---
> 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
>

2023-03-01 09:22:13

by Youling Tang

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

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 <[email protected]>
> ---
> 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;
> }
>


2023-03-01 09:30:34

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Hi, Youling,

On Wed, Mar 1, 2023 at 5:21 PM Youling Tang <[email protected]> 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 <[email protected]>
> > ---
> > 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;
> > }
> >
>

2023-03-01 09:44:24

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Hi, Ard,

On Wed, Mar 1, 2023 at 5:17 PM Ard Biesheuvel <[email protected]> wrote:
>
> On Wed, 1 Mar 2023 at 09:55, Huacai Chen <[email protected]> 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 <[email protected]>
> > ---
> > 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
> >

2023-03-01 10:08:03

by Youling Tang

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

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 <[email protected]> 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 <[email protected]>
>>> ---
>>> 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;
>>> }
>>>
>>


2023-03-01 12:07:28

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Hi, Youling,

On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <[email protected]> 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 <[email protected]> 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 <[email protected]>
> >>> ---
> >>> 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;
> >>> }
> >>>
> >>
>
>

2023-04-05 08:31:05

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Hi, Ard,

What is the status of this patch now?

Huacai

On Wed, Mar 1, 2023 at 8:06 PM Huacai Chen <[email protected]> wrote:
>
> Hi, Youling,
>
> On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > >>> ---
> > >>> 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;
> > >>> }
> > >>>
> > >>
> >
> >

2023-04-05 08:32:51

by Ard Biesheuvel

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

On Wed, 5 Apr 2023 at 10:14, Huacai Chen <[email protected]> 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 <[email protected]> wrote:
> >
> > Hi, Youling,
> >
> > On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > > >>> ---
> > > >>> 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;
> > > >>> }
> > > >>>
> > > >>
> > >
> > >

2023-04-05 10:02:33

by Huacai Chen

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

Hi, Ard,

On Wed, Apr 5, 2023 at 4:20 PM Ard Biesheuvel <[email protected]> wrote:
>
> On Wed, 5 Apr 2023 at 10:14, Huacai Chen <[email protected]> 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 <[email protected]> wrote:
> > >
> > > Hi, Youling,
> > >
> > > On Wed, Mar 1, 2023 at 6:08 PM Youling Tang <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > > > >>> ---
> > > > >>> 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;
> > > > >>> }
> > > > >>>
> > > > >>
> > > >
> > > >

2023-04-05 10:23:43

by Ard Biesheuvel

[permalink] [raw]
Subject: Re: [PATCH] efi/loongarch: Reintroduce efi_relocate_kernel() to relocate kernel

On Wed, 5 Apr 2023 at 11:57, Huacai Chen <[email protected]> wrote:
>
> Hi, Ard,
>
> On Wed, Apr 5, 2023 at 4:20 PM Ard Biesheuvel <[email protected]> wrote:
> >
> > On Wed, 5 Apr 2023 at 10:14, Huacai Chen <[email protected]> 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.