[2/2] riscv: kexec_file: Support loading Image binary file

Commit Message

Song Shuai Sept. 14, 2023, 2 a.m. UTC

This patch creates image_kexec_ops to load Image binary file
for kexec_file_load() syscall.

Signed-off-by: Song Shuai <[e-mail]>
---
 arch/riscv/include/asm/image.h         |  2 +
 arch/riscv/include/asm/kexec.h         |  1 +
 arch/riscv/kernel/Makefile             |  2 +-
 arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
 arch/riscv/kernel/machine_kexec_file.c |  1 +
 5 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/kernel/kexec_image.c

Comments

Emil Renner Berthing Sept. 14, 2023, 8:37 a.m. UTC | #1

Song Shuai wrote:
> This patch creates image_kexec_ops to load Image binary file
> for kexec_file_load() syscall.
>
> Signed-off-by: Song Shuai <[e-mail]>
> ---
>  arch/riscv/include/asm/image.h         |  2 +
>  arch/riscv/include/asm/kexec.h         |  1 +
>  arch/riscv/kernel/Makefile             |  2 +-
>  arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>  arch/riscv/kernel/machine_kexec_file.c |  1 +
>  5 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 arch/riscv/kernel/kexec_image.c
>
> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> index e0b319af3681..8927a6ea1127 100644
> --- a/arch/riscv/include/asm/image.h
> +++ b/arch/riscv/include/asm/image.h
> @@ -30,6 +30,8 @@
>  			      RISCV_HEADER_VERSION_MINOR)
>
>  #ifndef __ASSEMBLY__
> +#define riscv_image_flag_field(flags, field)\
> +			       (((flags) >> field##_SHIFT) & field##_MASK)

Hi Song,

This macro is almost FIELD_GET from linux/bitfield.h ..

>  /**
>   * struct riscv_image_header - riscv kernel image header
>   * @code0:		Executable code
> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> index 518825fe4160..b9ee8346cc8c 100644
> --- a/arch/riscv/include/asm/kexec.h
> +++ b/arch/riscv/include/asm/kexec.h
> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>
>  #ifdef CONFIG_KEXEC_FILE
>  extern const struct kexec_file_ops elf_kexec_ops;
> +extern const struct kexec_file_ops image_kexec_ops;
>
>  struct purgatory_info;
>  int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 1c62c639e875..9ecba3231a36 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -86,7 +86,7 @@ endif
>  obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>  obj-$(CONFIG_KGDB)		+= kgdb.o
>  obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>  obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>  obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>
> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> new file mode 100644
> index 000000000000..b6aa7f59bd53
> --- /dev/null
> +++ b/arch/riscv/kernel/kexec_image.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RISC-V Kexec image loader
> + *
> + */
> +
> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/kexec.h>
> +#include <linux/pe.h>
> +#include <linux/string.h>
> +#include <asm/byteorder.h>
> +#include <asm/image.h>
> +
> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> +{
> +	const struct riscv_image_header *h =
> +		(const struct riscv_image_header *)(kernel_buf);
> +
> +	if (!h || (kernel_len < sizeof(*h)))
> +		return -EINVAL;
> +
> +	/* According to Documentation/riscv/boot-image-header.rst,
> +	 * use "magic2" field to check when version >= 0.2.
> +	 */
> +
> +	if (h->version >= RISCV_HEADER_VERSION &&
> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static void *image_load(struct kimage *image,
> +				char *kernel, unsigned long kernel_len,
> +				char *initrd, unsigned long initrd_len,
> +				char *cmdline, unsigned long cmdline_len)
> +{
> +	struct riscv_image_header *h;
> +	u64 flags;
> +	bool be_image, be_kernel;
> +	struct kexec_buf kbuf;
> +	int ret;
> +
> +	/* Check Image header */
> +	h = (struct riscv_image_header *)kernel;
> +	if (!h->image_size) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* Check endianness */
> +	flags = le64_to_cpu(h->flags);
> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);

..but here you're just testing a single bit, so since be_image is a bool it
could just be
	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;

/Emil

> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> +	if (be_image != be_kernel) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* Load the kernel image */
> +	kbuf.image = image;
> +	kbuf.buf_min = 0;
> +	kbuf.buf_max = ULONG_MAX;
> +	kbuf.top_down = false;
> +
> +	kbuf.buffer = kernel;
> +	kbuf.bufsz = kernel_len;
> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> +	kbuf.memsz = le64_to_cpu(h->image_size);
> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> +
> +	ret = kexec_add_buffer(&kbuf);
> +	if (ret) {
> +		pr_err("Error add kernel image ret=%d\n", ret);
> +		goto out;
> +	}
> +
> +	image->start = kbuf.mem;
> +
> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> +
> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> +				  initrd, initrd_len, cmdline, cmdline_len);
> +
> +out:
> +	return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +const struct kexec_file_ops image_kexec_ops = {
> +	.probe = image_probe,
> +	.load = image_load,
> +};
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index aedb8c16a283..5dc700834f1e 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -17,6 +17,7 @@
>
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>  	&elf_kexec_ops,
> +	&image_kexec_ops,
>  	NULL
>  };
>
> --
> 2.20.1
>
>
> _______________________________________________
> linux-riscv mailing list
> [e-mail]
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Song Shuai Oct. 11, 2023, 6:03 a.m. UTC | #2

在 2023/9/14 16:37, Emil Renner Berthing 写道:
> Song Shuai wrote:
>> This patch creates image_kexec_ops to load Image binary file
>> for kexec_file_load() syscall.
>>
>> Signed-off-by: Song Shuai <[e-mail]>
>> ---
>>   arch/riscv/include/asm/image.h         |  2 +
>>   arch/riscv/include/asm/kexec.h         |  1 +
>>   arch/riscv/kernel/Makefile             |  2 +-
>>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>   arch/riscv/kernel/machine_kexec_file.c |  1 +
>>   5 files changed, 102 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/riscv/kernel/kexec_image.c
>>
>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>> index e0b319af3681..8927a6ea1127 100644
>> --- a/arch/riscv/include/asm/image.h
>> +++ b/arch/riscv/include/asm/image.h
>> @@ -30,6 +30,8 @@
>>   			      RISCV_HEADER_VERSION_MINOR)
>>
>>   #ifndef __ASSEMBLY__
>> +#define riscv_image_flag_field(flags, field)\
>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> 
> Hi Song,
> 
> This macro is almost FIELD_GET from linux/bitfield.h ..
> 
>>   /**
>>    * struct riscv_image_header - riscv kernel image header
>>    * @code0:		Executable code
>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>> index 518825fe4160..b9ee8346cc8c 100644
>> --- a/arch/riscv/include/asm/kexec.h
>> +++ b/arch/riscv/include/asm/kexec.h
>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>
>>   #ifdef CONFIG_KEXEC_FILE
>>   extern const struct kexec_file_ops elf_kexec_ops;
>> +extern const struct kexec_file_ops image_kexec_ops;
>>
>>   struct purgatory_info;
>>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>> index 1c62c639e875..9ecba3231a36 100644
>> --- a/arch/riscv/kernel/Makefile
>> +++ b/arch/riscv/kernel/Makefile
>> @@ -86,7 +86,7 @@ endif
>>   obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>>   obj-$(CONFIG_KGDB)		+= kgdb.o
>>   obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>>   obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>>   obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>>
>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>> new file mode 100644
>> index 000000000000..b6aa7f59bd53
>> --- /dev/null
>> +++ b/arch/riscv/kernel/kexec_image.c
>> @@ -0,0 +1,97 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * RISC-V Kexec image loader
>> + *
>> + */
>> +
>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
>> +
>> +#include <linux/err.h>
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/kexec.h>
>> +#include <linux/pe.h>
>> +#include <linux/string.h>
>> +#include <asm/byteorder.h>
>> +#include <asm/image.h>
>> +
>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>> +{
>> +	const struct riscv_image_header *h =
>> +		(const struct riscv_image_header *)(kernel_buf);
>> +
>> +	if (!h || (kernel_len < sizeof(*h)))
>> +		return -EINVAL;
>> +
>> +	/* According to Documentation/riscv/boot-image-header.rst,
>> +	 * use "magic2" field to check when version >= 0.2.
>> +	 */
>> +
>> +	if (h->version >= RISCV_HEADER_VERSION &&
>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>> +		return -EINVAL;
>> +
>> +	return 0;
>> +}
>> +
>> +static void *image_load(struct kimage *image,
>> +				char *kernel, unsigned long kernel_len,
>> +				char *initrd, unsigned long initrd_len,
>> +				char *cmdline, unsigned long cmdline_len)
>> +{
>> +	struct riscv_image_header *h;
>> +	u64 flags;
>> +	bool be_image, be_kernel;
>> +	struct kexec_buf kbuf;
>> +	int ret;
>> +
>> +	/* Check Image header */
>> +	h = (struct riscv_image_header *)kernel;
>> +	if (!h->image_size) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	/* Check endianness */
>> +	flags = le64_to_cpu(h->flags);
>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> 
> ..but here you're just testing a single bit, so since be_image is a bool it
> could just be
> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> 
> /Emil
Hi Emil,

Sorry for the delayed response,

The `flags` field currently only has bit-0 to indicate the kenrel 
endianness, your comment looks good in this case.

While considering the future extension of the `flags` feild, the 
riscv_image_flag_field() is neccessiry to make callers to require the 
bits they want.

So I prefer to keep this snippet.
> 
>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>> +	if (be_image != be_kernel) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	/* Load the kernel image */
>> +	kbuf.image = image;
>> +	kbuf.buf_min = 0;
>> +	kbuf.buf_max = ULONG_MAX;
>> +	kbuf.top_down = false;
>> +
>> +	kbuf.buffer = kernel;
>> +	kbuf.bufsz = kernel_len;
>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>> +	kbuf.memsz = le64_to_cpu(h->image_size);
>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
>> +
>> +	ret = kexec_add_buffer(&kbuf);
>> +	if (ret) {
>> +		pr_err("Error add kernel image ret=%d\n", ret);
>> +		goto out;
>> +	}
>> +
>> +	image->start = kbuf.mem;
>> +
>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
>> +
>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>> +				  initrd, initrd_len, cmdline, cmdline_len);
>> +
>> +out:
>> +	return ret ? ERR_PTR(ret) : NULL;
>> +}
>> +
>> +const struct kexec_file_ops image_kexec_ops = {
>> +	.probe = image_probe,
>> +	.load = image_load,
>> +};
>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>> index aedb8c16a283..5dc700834f1e 100644
>> --- a/arch/riscv/kernel/machine_kexec_file.c
>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>> @@ -17,6 +17,7 @@
>>
>>   const struct kexec_file_ops * const kexec_file_loaders[] = {
>>   	&elf_kexec_ops,
>> +	&image_kexec_ops,
>>   	NULL
>>   };
>>
>> --
>> 2.20.1
>>
>>
>> _______________________________________________
>> linux-riscv mailing list
>> [e-mail]
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>

Emil Renner Berthing Oct. 11, 2023, 10:48 a.m. UTC | #3

Song Shuai wrote:
>
>
> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
> > Song Shuai wrote:
> >> This patch creates image_kexec_ops to load Image binary file
> >> for kexec_file_load() syscall.
> >>
> >> Signed-off-by: Song Shuai <[e-mail]>
> >> ---
> >>   arch/riscv/include/asm/image.h         |  2 +
> >>   arch/riscv/include/asm/kexec.h         |  1 +
> >>   arch/riscv/kernel/Makefile             |  2 +-
> >>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>   arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>   5 files changed, 102 insertions(+), 1 deletion(-)
> >>   create mode 100644 arch/riscv/kernel/kexec_image.c
> >>
> >> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >> index e0b319af3681..8927a6ea1127 100644
> >> --- a/arch/riscv/include/asm/image.h
> >> +++ b/arch/riscv/include/asm/image.h
> >> @@ -30,6 +30,8 @@
> >>   			      RISCV_HEADER_VERSION_MINOR)
> >>
> >>   #ifndef __ASSEMBLY__
> >> +#define riscv_image_flag_field(flags, field)\
> >> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> >
> > Hi Song,
> >
> > This macro is almost FIELD_GET from linux/bitfield.h ..
> >
> >>   /**
> >>    * struct riscv_image_header - riscv kernel image header
> >>    * @code0:		Executable code
> >> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >> index 518825fe4160..b9ee8346cc8c 100644
> >> --- a/arch/riscv/include/asm/kexec.h
> >> +++ b/arch/riscv/include/asm/kexec.h
> >> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>
> >>   #ifdef CONFIG_KEXEC_FILE
> >>   extern const struct kexec_file_ops elf_kexec_ops;
> >> +extern const struct kexec_file_ops image_kexec_ops;
> >>
> >>   struct purgatory_info;
> >>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >> index 1c62c639e875..9ecba3231a36 100644
> >> --- a/arch/riscv/kernel/Makefile
> >> +++ b/arch/riscv/kernel/Makefile
> >> @@ -86,7 +86,7 @@ endif
> >>   obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
> >>   obj-$(CONFIG_KGDB)		+= kgdb.o
> >>   obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> >> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> >> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
> >>   obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
> >>   obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
> >>
> >> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >> new file mode 100644
> >> index 000000000000..b6aa7f59bd53
> >> --- /dev/null
> >> +++ b/arch/riscv/kernel/kexec_image.c
> >> @@ -0,0 +1,97 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * RISC-V Kexec image loader
> >> + *
> >> + */
> >> +
> >> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> >> +
> >> +#include <linux/err.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/kexec.h>
> >> +#include <linux/pe.h>
> >> +#include <linux/string.h>
> >> +#include <asm/byteorder.h>
> >> +#include <asm/image.h>
> >> +
> >> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >> +{
> >> +	const struct riscv_image_header *h =
> >> +		(const struct riscv_image_header *)(kernel_buf);
> >> +
> >> +	if (!h || (kernel_len < sizeof(*h)))
> >> +		return -EINVAL;
> >> +
> >> +	/* According to Documentation/riscv/boot-image-header.rst,
> >> +	 * use "magic2" field to check when version >= 0.2.
> >> +	 */
> >> +
> >> +	if (h->version >= RISCV_HEADER_VERSION &&
> >> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >> +		return -EINVAL;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void *image_load(struct kimage *image,
> >> +				char *kernel, unsigned long kernel_len,
> >> +				char *initrd, unsigned long initrd_len,
> >> +				char *cmdline, unsigned long cmdline_len)
> >> +{
> >> +	struct riscv_image_header *h;
> >> +	u64 flags;
> >> +	bool be_image, be_kernel;
> >> +	struct kexec_buf kbuf;
> >> +	int ret;
> >> +
> >> +	/* Check Image header */
> >> +	h = (struct riscv_image_header *)kernel;
> >> +	if (!h->image_size) {
> >> +		ret = -EINVAL;
> >> +		goto out;
> >> +	}
> >> +
> >> +	/* Check endianness */
> >> +	flags = le64_to_cpu(h->flags);
> >> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >
> > ..but here you're just testing a single bit, so since be_image is a bool it
> > could just be
> > 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> >
> > /Emil
> Hi Emil,
>
> Sorry for the delayed response,
>
> The `flags` field currently only has bit-0 to indicate the kenrel
> endianness, your comment looks good in this case.
>
> While considering the future extension of the `flags` feild, the
> riscv_image_flag_field() is neccessiry to make callers to require the
> bits they want.

Right, but please don't invent your own FIELD_GET then.

>
> So I prefer to keep this snippet.
> >
> >> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >> +	if (be_image != be_kernel) {
> >> +		ret = -EINVAL;
> >> +		goto out;
> >> +	}
> >> +
> >> +	/* Load the kernel image */
> >> +	kbuf.image = image;
> >> +	kbuf.buf_min = 0;
> >> +	kbuf.buf_max = ULONG_MAX;
> >> +	kbuf.top_down = false;
> >> +
> >> +	kbuf.buffer = kernel;
> >> +	kbuf.bufsz = kernel_len;
> >> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >> +	kbuf.memsz = le64_to_cpu(h->image_size);
> >> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> >> +
> >> +	ret = kexec_add_buffer(&kbuf);
> >> +	if (ret) {
> >> +		pr_err("Error add kernel image ret=%d\n", ret);
> >> +		goto out;
> >> +	}
> >> +
> >> +	image->start = kbuf.mem;
> >> +
> >> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >> +
> >> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >> +				  initrd, initrd_len, cmdline, cmdline_len);
> >> +
> >> +out:
> >> +	return ret ? ERR_PTR(ret) : NULL;
> >> +}
> >> +
> >> +const struct kexec_file_ops image_kexec_ops = {
> >> +	.probe = image_probe,
> >> +	.load = image_load,
> >> +};
> >> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >> index aedb8c16a283..5dc700834f1e 100644
> >> --- a/arch/riscv/kernel/machine_kexec_file.c
> >> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >> @@ -17,6 +17,7 @@
> >>
> >>   const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>   	&elf_kexec_ops,
> >> +	&image_kexec_ops,
> >>   	NULL
> >>   };
> >>
> >> --
> >> 2.20.1
> >>
> >>
> >> _______________________________________________
> >> linux-riscv mailing list
> >> [e-mail]
> >> http://lists.infradead.org/mailman/listinfo/linux-riscv
> >
>
> --
> Thanks
> Song Shuai
>
>
> _______________________________________________
> linux-riscv mailing list
> [e-mail]
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Song Shuai Oct. 16, 2023, 5:19 a.m. UTC | #4

在 2023/10/11 18:48, Emil Renner Berthing 写道:
> Song Shuai wrote:
>>
>>
>> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
>>> Song Shuai wrote:
>>>> This patch creates image_kexec_ops to load Image binary file
>>>> for kexec_file_load() syscall.
>>>>
>>>> Signed-off-by: Song Shuai <[e-mail]>
>>>> ---
>>>>    arch/riscv/include/asm/image.h         |  2 +
>>>>    arch/riscv/include/asm/kexec.h         |  1 +
>>>>    arch/riscv/kernel/Makefile             |  2 +-
>>>>    arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>>>    arch/riscv/kernel/machine_kexec_file.c |  1 +
>>>>    5 files changed, 102 insertions(+), 1 deletion(-)
>>>>    create mode 100644 arch/riscv/kernel/kexec_image.c
>>>>
>>>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>>>> index e0b319af3681..8927a6ea1127 100644
>>>> --- a/arch/riscv/include/asm/image.h
>>>> +++ b/arch/riscv/include/asm/image.h
>>>> @@ -30,6 +30,8 @@
>>>>    			      RISCV_HEADER_VERSION_MINOR)
>>>>
>>>>    #ifndef __ASSEMBLY__
>>>> +#define riscv_image_flag_field(flags, field)\
>>>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
>>>
>>> Hi Song,
>>>
>>> This macro is almost FIELD_GET from linux/bitfield.h ..
>>>
>>>>    /**
>>>>     * struct riscv_image_header - riscv kernel image header
>>>>     * @code0:		Executable code
>>>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>>>> index 518825fe4160..b9ee8346cc8c 100644
>>>> --- a/arch/riscv/include/asm/kexec.h
>>>> +++ b/arch/riscv/include/asm/kexec.h
>>>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>>>
>>>>    #ifdef CONFIG_KEXEC_FILE
>>>>    extern const struct kexec_file_ops elf_kexec_ops;
>>>> +extern const struct kexec_file_ops image_kexec_ops;
>>>>
>>>>    struct purgatory_info;
>>>>    int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>>>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>>>> index 1c62c639e875..9ecba3231a36 100644
>>>> --- a/arch/riscv/kernel/Makefile
>>>> +++ b/arch/riscv/kernel/Makefile
>>>> @@ -86,7 +86,7 @@ endif
>>>>    obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>>>>    obj-$(CONFIG_KGDB)		+= kgdb.o
>>>>    obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
>>>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
>>>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>>>>    obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>>>>    obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>>>>
>>>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>>>> new file mode 100644
>>>> index 000000000000..b6aa7f59bd53
>>>> --- /dev/null
>>>> +++ b/arch/riscv/kernel/kexec_image.c
>>>> @@ -0,0 +1,97 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * RISC-V Kexec image loader
>>>> + *
>>>> + */
>>>> +
>>>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
>>>> +
>>>> +#include <linux/err.h>
>>>> +#include <linux/errno.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/kexec.h>
>>>> +#include <linux/pe.h>
>>>> +#include <linux/string.h>
>>>> +#include <asm/byteorder.h>
>>>> +#include <asm/image.h>
>>>> +
>>>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>>>> +{
>>>> +	const struct riscv_image_header *h =
>>>> +		(const struct riscv_image_header *)(kernel_buf);
>>>> +
>>>> +	if (!h || (kernel_len < sizeof(*h)))
>>>> +		return -EINVAL;
>>>> +
>>>> +	/* According to Documentation/riscv/boot-image-header.rst,
>>>> +	 * use "magic2" field to check when version >= 0.2.
>>>> +	 */
>>>> +
>>>> +	if (h->version >= RISCV_HEADER_VERSION &&
>>>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>>>> +		return -EINVAL;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static void *image_load(struct kimage *image,
>>>> +				char *kernel, unsigned long kernel_len,
>>>> +				char *initrd, unsigned long initrd_len,
>>>> +				char *cmdline, unsigned long cmdline_len)
>>>> +{
>>>> +	struct riscv_image_header *h;
>>>> +	u64 flags;
>>>> +	bool be_image, be_kernel;
>>>> +	struct kexec_buf kbuf;
>>>> +	int ret;
>>>> +
>>>> +	/* Check Image header */
>>>> +	h = (struct riscv_image_header *)kernel;
>>>> +	if (!h->image_size) {
>>>> +		ret = -EINVAL;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	/* Check endianness */
>>>> +	flags = le64_to_cpu(h->flags);
>>>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
>>>
>>> ..but here you're just testing a single bit, so since be_image is a bool it
>>> could just be
>>> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
>>>
>>> /Emil
>> Hi Emil,
>>
>> Sorry for the delayed response,
>>
>> The `flags` field currently only has bit-0 to indicate the kenrel
>> endianness, your comment looks good in this case.
>>
>> While considering the future extension of the `flags` feild, the
>> riscv_image_flag_field() is neccessiry to make callers to require the
>> bits they want.
> 
> Right, but please don't invent your own FIELD_GET then.

Hi Emil,

I tried to use FIELD_PREP/FIELD_GET to set/get the RISCV_IMAGE_FLAG_BE,
but using FIELD_PREP to define the __HEAD_FLAGS (used in head.S) emitted 
AS build error and the final .s file looked like:

  883  .dword _end - _start
  884  .dword (({ ({ do { } while (0); do { } while (0); do { } while 
(0); do { } while (0); do { } while (0); }); ((typeof((((1)) << 
(0))))(0) << (__builtin_ffsll((((1)) << (0))) - 1)) & ((((1)) << (0))); }))

IIUC the FIELD_PREP can't work well in this asm context, and using 
FILED_GET without FIELD_PREP paired looks not good to me.

The original riscv/*/image.h and the riscv_image_flag_filed() of this 
patch just do what arm64 does, so I still like to keep them.

I also found that Patch1 has a build issue due to my previous uncareful 
cherry-picking,
V2 will be sent to fix it if you're ok this patch without bitfield armed.

I would like to listen to your advice.

> 
>>
>> So I prefer to keep this snippet.
>>>
>>>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>>>> +	if (be_image != be_kernel) {
>>>> +		ret = -EINVAL;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	/* Load the kernel image */
>>>> +	kbuf.image = image;
>>>> +	kbuf.buf_min = 0;
>>>> +	kbuf.buf_max = ULONG_MAX;
>>>> +	kbuf.top_down = false;
>>>> +
>>>> +	kbuf.buffer = kernel;
>>>> +	kbuf.bufsz = kernel_len;
>>>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>>>> +	kbuf.memsz = le64_to_cpu(h->image_size);
>>>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
>>>> +
>>>> +	ret = kexec_add_buffer(&kbuf);
>>>> +	if (ret) {
>>>> +		pr_err("Error add kernel image ret=%d\n", ret);
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	image->start = kbuf.mem;
>>>> +
>>>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>>>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
>>>> +
>>>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>>>> +				  initrd, initrd_len, cmdline, cmdline_len);
>>>> +
>>>> +out:
>>>> +	return ret ? ERR_PTR(ret) : NULL;
>>>> +}
>>>> +
>>>> +const struct kexec_file_ops image_kexec_ops = {
>>>> +	.probe = image_probe,
>>>> +	.load = image_load,
>>>> +};
>>>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>>>> index aedb8c16a283..5dc700834f1e 100644
>>>> --- a/arch/riscv/kernel/machine_kexec_file.c
>>>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>>>> @@ -17,6 +17,7 @@
>>>>
>>>>    const struct kexec_file_ops * const kexec_file_loaders[] = {
>>>>    	&elf_kexec_ops,
>>>> +	&image_kexec_ops,
>>>>    	NULL
>>>>    };
>>>>
>>>> --
>>>> 2.20.1
>>>>
>>>>
>>>> _______________________________________________
>>>> linux-riscv mailing list
>>>> [e-mail]
>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>
>>
>> --
>> Thanks
>> Song Shuai
>>
>>
>> _______________________________________________
>> linux-riscv mailing list
>> [e-mail]
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>

Emil Renner Berthing Oct. 16, 2023, 8:17 a.m. UTC | #5

Song Shuai wrote:
>
>
> 在 2023/10/11 18:48, Emil Renner Berthing 写道:
> > Song Shuai wrote:
> >>
> >>
> >> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
> >>> Song Shuai wrote:
> >>>> This patch creates image_kexec_ops to load Image binary file
> >>>> for kexec_file_load() syscall.
> >>>>
> >>>> Signed-off-by: Song Shuai <[e-mail]>
> >>>> ---
> >>>>    arch/riscv/include/asm/image.h         |  2 +
> >>>>    arch/riscv/include/asm/kexec.h         |  1 +
> >>>>    arch/riscv/kernel/Makefile             |  2 +-
> >>>>    arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>>>    arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>>>    5 files changed, 102 insertions(+), 1 deletion(-)
> >>>>    create mode 100644 arch/riscv/kernel/kexec_image.c
> >>>>
> >>>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >>>> index e0b319af3681..8927a6ea1127 100644
> >>>> --- a/arch/riscv/include/asm/image.h
> >>>> +++ b/arch/riscv/include/asm/image.h
> >>>> @@ -30,6 +30,8 @@
> >>>>    			      RISCV_HEADER_VERSION_MINOR)
> >>>>
> >>>>    #ifndef __ASSEMBLY__
> >>>> +#define riscv_image_flag_field(flags, field)\
> >>>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> >>>
> >>> Hi Song,
> >>>
> >>> This macro is almost FIELD_GET from linux/bitfield.h ..
> >>>
> >>>>    /**
> >>>>     * struct riscv_image_header - riscv kernel image header
> >>>>     * @code0:		Executable code
> >>>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >>>> index 518825fe4160..b9ee8346cc8c 100644
> >>>> --- a/arch/riscv/include/asm/kexec.h
> >>>> +++ b/arch/riscv/include/asm/kexec.h
> >>>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>>>
> >>>>    #ifdef CONFIG_KEXEC_FILE
> >>>>    extern const struct kexec_file_ops elf_kexec_ops;
> >>>> +extern const struct kexec_file_ops image_kexec_ops;
> >>>>
> >>>>    struct purgatory_info;
> >>>>    int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >>>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >>>> index 1c62c639e875..9ecba3231a36 100644
> >>>> --- a/arch/riscv/kernel/Makefile
> >>>> +++ b/arch/riscv/kernel/Makefile
> >>>> @@ -86,7 +86,7 @@ endif
> >>>>    obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
> >>>>    obj-$(CONFIG_KGDB)		+= kgdb.o
> >>>>    obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> >>>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> >>>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
> >>>>    obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
> >>>>    obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
> >>>>
> >>>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >>>> new file mode 100644
> >>>> index 000000000000..b6aa7f59bd53
> >>>> --- /dev/null
> >>>> +++ b/arch/riscv/kernel/kexec_image.c
> >>>> @@ -0,0 +1,97 @@
> >>>> +// SPDX-License-Identifier: GPL-2.0
> >>>> +/*
> >>>> + * RISC-V Kexec image loader
> >>>> + *
> >>>> + */
> >>>> +
> >>>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> >>>> +
> >>>> +#include <linux/err.h>
> >>>> +#include <linux/errno.h>
> >>>> +#include <linux/kernel.h>
> >>>> +#include <linux/kexec.h>
> >>>> +#include <linux/pe.h>
> >>>> +#include <linux/string.h>
> >>>> +#include <asm/byteorder.h>
> >>>> +#include <asm/image.h>
> >>>> +
> >>>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >>>> +{
> >>>> +	const struct riscv_image_header *h =
> >>>> +		(const struct riscv_image_header *)(kernel_buf);
> >>>> +
> >>>> +	if (!h || (kernel_len < sizeof(*h)))
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	/* According to Documentation/riscv/boot-image-header.rst,
> >>>> +	 * use "magic2" field to check when version >= 0.2.
> >>>> +	 */
> >>>> +
> >>>> +	if (h->version >= RISCV_HEADER_VERSION &&
> >>>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static void *image_load(struct kimage *image,
> >>>> +				char *kernel, unsigned long kernel_len,
> >>>> +				char *initrd, unsigned long initrd_len,
> >>>> +				char *cmdline, unsigned long cmdline_len)
> >>>> +{
> >>>> +	struct riscv_image_header *h;
> >>>> +	u64 flags;
> >>>> +	bool be_image, be_kernel;
> >>>> +	struct kexec_buf kbuf;
> >>>> +	int ret;
> >>>> +
> >>>> +	/* Check Image header */
> >>>> +	h = (struct riscv_image_header *)kernel;
> >>>> +	if (!h->image_size) {
> >>>> +		ret = -EINVAL;
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	/* Check endianness */
> >>>> +	flags = le64_to_cpu(h->flags);
> >>>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >>>
> >>> ..but here you're just testing a single bit, so since be_image is a bool it
> >>> could just be
> >>> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> >>>
> >>> /Emil
> >> Hi Emil,
> >>
> >> Sorry for the delayed response,
> >>
> >> The `flags` field currently only has bit-0 to indicate the kenrel
> >> endianness, your comment looks good in this case.
> >>
> >> While considering the future extension of the `flags` feild, the
> >> riscv_image_flag_field() is neccessiry to make callers to require the
> >> bits they want.
> >
> > Right, but please don't invent your own FIELD_GET then.
>
> Hi Emil,
>
> I tried to use FIELD_PREP/FIELD_GET to set/get the RISCV_IMAGE_FLAG_BE,
> but using FIELD_PREP to define the __HEAD_FLAGS (used in head.S) emitted
> AS build error and the final .s file looked like:
>
>   883  .dword _end - _start
>   884  .dword (({ ({ do { } while (0); do { } while (0); do { } while
> (0); do { } while (0); do { } while (0); }); ((typeof((((1)) <<
> (0))))(0) << (__builtin_ffsll((((1)) << (0))) - 1)) & ((((1)) << (0))); }))
>
> IIUC the FIELD_PREP can't work well in this asm context, and using
> FILED_GET without FIELD_PREP paired looks not good to me.
>
> The original riscv/*/image.h and the riscv_image_flag_filed() of this
> patch just do what arm64 does, so I still like to keep them.

Hi Song,

Your riscv_image_flag_field macro is already guarded by a #ifndef __ASSEMBLY__
and your patches above doesn't touch any __HEAD_FLAGS macro, so I don't know
what you're trying to do with FIELD_PREP.

What I'm saying is that instead of defining the riscv_image_flag_field macro
you can just do

-be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
+be_image = FIELD_GET(RISCV_IMAGE_FLAG_BE, flags);

/Emil

> I also found that Patch1 has a build issue due to my previous uncareful
> cherry-picking,
> V2 will be sent to fix it if you're ok this patch without bitfield armed.
>
> I would like to listen to your advice.
>
> >
> >>
> >> So I prefer to keep this snippet.
> >>>
> >>>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >>>> +	if (be_image != be_kernel) {
> >>>> +		ret = -EINVAL;
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	/* Load the kernel image */
> >>>> +	kbuf.image = image;
> >>>> +	kbuf.buf_min = 0;
> >>>> +	kbuf.buf_max = ULONG_MAX;
> >>>> +	kbuf.top_down = false;
> >>>> +
> >>>> +	kbuf.buffer = kernel;
> >>>> +	kbuf.bufsz = kernel_len;
> >>>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >>>> +	kbuf.memsz = le64_to_cpu(h->image_size);
> >>>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> >>>> +
> >>>> +	ret = kexec_add_buffer(&kbuf);
> >>>> +	if (ret) {
> >>>> +		pr_err("Error add kernel image ret=%d\n", ret);
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	image->start = kbuf.mem;
> >>>> +
> >>>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >>>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >>>> +
> >>>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >>>> +				  initrd, initrd_len, cmdline, cmdline_len);
> >>>> +
> >>>> +out:
> >>>> +	return ret ? ERR_PTR(ret) : NULL;
> >>>> +}
> >>>> +
> >>>> +const struct kexec_file_ops image_kexec_ops = {
> >>>> +	.probe = image_probe,
> >>>> +	.load = image_load,
> >>>> +};
> >>>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >>>> index aedb8c16a283..5dc700834f1e 100644
> >>>> --- a/arch/riscv/kernel/machine_kexec_file.c
> >>>> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >>>> @@ -17,6 +17,7 @@
> >>>>
> >>>>    const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>>>    	&elf_kexec_ops,
> >>>> +	&image_kexec_ops,
> >>>>    	NULL
> >>>>    };
> >>>>
> >>>> --
> >>>> 2.20.1

yunhui cui Feb. 16, 2024, 8:54 a.m. UTC | #6

Hi Shuai,

On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <[e-mail]> wrote:
>
> This patch creates image_kexec_ops to load Image binary file
> for kexec_file_load() syscall.
>
> Signed-off-by: Song Shuai <[e-mail]>
> ---
>  arch/riscv/include/asm/image.h         |  2 +
>  arch/riscv/include/asm/kexec.h         |  1 +
>  arch/riscv/kernel/Makefile             |  2 +-
>  arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>  arch/riscv/kernel/machine_kexec_file.c |  1 +
>  5 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 arch/riscv/kernel/kexec_image.c
>
> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> index e0b319af3681..8927a6ea1127 100644
> --- a/arch/riscv/include/asm/image.h
> +++ b/arch/riscv/include/asm/image.h
> @@ -30,6 +30,8 @@
>                               RISCV_HEADER_VERSION_MINOR)
>
>  #ifndef __ASSEMBLY__
> +#define riscv_image_flag_field(flags, field)\
> +                              (((flags) >> field##_SHIFT) & field##_MASK)
>  /**
>   * struct riscv_image_header - riscv kernel image header
>   * @code0:             Executable code
> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> index 518825fe4160..b9ee8346cc8c 100644
> --- a/arch/riscv/include/asm/kexec.h
> +++ b/arch/riscv/include/asm/kexec.h
> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>
>  #ifdef CONFIG_KEXEC_FILE
>  extern const struct kexec_file_ops elf_kexec_ops;
> +extern const struct kexec_file_ops image_kexec_ops;
>
>  struct purgatory_info;
>  int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 1c62c639e875..9ecba3231a36 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -86,7 +86,7 @@ endif
>  obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
>  obj-$(CONFIG_KGDB)             += kgdb.o
>  obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
>  obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
>  obj-$(CONFIG_CRASH_CORE)       += crash_core.o
>
> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> new file mode 100644
> index 000000000000..b6aa7f59bd53
> --- /dev/null
> +++ b/arch/riscv/kernel/kexec_image.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RISC-V Kexec image loader
> + *
> + */
> +
> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/kexec.h>
> +#include <linux/pe.h>
> +#include <linux/string.h>
> +#include <asm/byteorder.h>
> +#include <asm/image.h>
> +
> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> +{
> +       const struct riscv_image_header *h =
> +               (const struct riscv_image_header *)(kernel_buf);
> +
> +       if (!h || (kernel_len < sizeof(*h)))
> +               return -EINVAL;
> +
> +       /* According to Documentation/riscv/boot-image-header.rst,
> +        * use "magic2" field to check when version >= 0.2.
> +        */
> +
> +       if (h->version >= RISCV_HEADER_VERSION &&
> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +
> +static void *image_load(struct kimage *image,
> +                               char *kernel, unsigned long kernel_len,
> +                               char *initrd, unsigned long initrd_len,
> +                               char *cmdline, unsigned long cmdline_len)
> +{
> +       struct riscv_image_header *h;
> +       u64 flags;
> +       bool be_image, be_kernel;
> +       struct kexec_buf kbuf;
> +       int ret;
> +
> +       /* Check Image header */
> +       h = (struct riscv_image_header *)kernel;
> +       if (!h->image_size) {
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       /* Check endianness */
> +       flags = le64_to_cpu(h->flags);
> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> +       if (be_image != be_kernel) {
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       /* Load the kernel image */
> +       kbuf.image = image;
> +       kbuf.buf_min = 0;
> +       kbuf.buf_max = ULONG_MAX;
> +       kbuf.top_down = false;
> +
> +       kbuf.buffer = kernel;
> +       kbuf.bufsz = kernel_len;
> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> +       kbuf.memsz = le64_to_cpu(h->image_size);
> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
> +
> +       ret = kexec_add_buffer(&kbuf);
> +       if (ret) {
> +               pr_err("Error add kernel image ret=%d\n", ret);
> +               goto out;
> +       }
> +
> +       image->start = kbuf.mem;
> +
> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);

pr_info() or pr_debug()?


> +
> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> +                                 initrd, initrd_len, cmdline, cmdline_len);
> +
> +out:
> +       return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +const struct kexec_file_ops image_kexec_ops = {
> +       .probe = image_probe,
> +       .load = image_load,
> +};
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index aedb8c16a283..5dc700834f1e 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -17,6 +17,7 @@
>
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>         &elf_kexec_ops,
> +       &image_kexec_ops,
>         NULL
>  };
>
> --
> 2.20.1
>

I tested these two patches. It works when
CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
follows:

[45.712019] Unknown rela relocation: 34
[45.712258] Error loading purgatory ret=-8

How to fix it?

Thanks，
Yunhui

Song Shuai Feb. 19, 2024, 9:52 a.m. UTC | #7

Hi, yunhui:

在 2024/2/16 16:54, yunhui cui 写道:
> Hi Shuai,
> 
> On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <[e-mail]> wrote:
>>
>> This patch creates image_kexec_ops to load Image binary file
>> for kexec_file_load() syscall.
>>
>> Signed-off-by: Song Shuai <[e-mail]>
>> ---
>>   arch/riscv/include/asm/image.h         |  2 +
>>   arch/riscv/include/asm/kexec.h         |  1 +
>>   arch/riscv/kernel/Makefile             |  2 +-
>>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>   arch/riscv/kernel/machine_kexec_file.c |  1 +
>>   5 files changed, 102 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/riscv/kernel/kexec_image.c
>>
>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>> index e0b319af3681..8927a6ea1127 100644
>> --- a/arch/riscv/include/asm/image.h
>> +++ b/arch/riscv/include/asm/image.h
>> @@ -30,6 +30,8 @@
>>                                RISCV_HEADER_VERSION_MINOR)
>>
>>   #ifndef __ASSEMBLY__
>> +#define riscv_image_flag_field(flags, field)\
>> +                              (((flags) >> field##_SHIFT) & field##_MASK)
>>   /**
>>    * struct riscv_image_header - riscv kernel image header
>>    * @code0:             Executable code
>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>> index 518825fe4160..b9ee8346cc8c 100644
>> --- a/arch/riscv/include/asm/kexec.h
>> +++ b/arch/riscv/include/asm/kexec.h
>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>
>>   #ifdef CONFIG_KEXEC_FILE
>>   extern const struct kexec_file_ops elf_kexec_ops;
>> +extern const struct kexec_file_ops image_kexec_ops;
>>
>>   struct purgatory_info;
>>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>> index 1c62c639e875..9ecba3231a36 100644
>> --- a/arch/riscv/kernel/Makefile
>> +++ b/arch/riscv/kernel/Makefile
>> @@ -86,7 +86,7 @@ endif
>>   obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
>>   obj-$(CONFIG_KGDB)             += kgdb.o
>>   obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
>> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
>> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
>>   obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
>>   obj-$(CONFIG_CRASH_CORE)       += crash_core.o
>>
>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>> new file mode 100644
>> index 000000000000..b6aa7f59bd53
>> --- /dev/null
>> +++ b/arch/riscv/kernel/kexec_image.c
>> @@ -0,0 +1,97 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * RISC-V Kexec image loader
>> + *
>> + */
>> +
>> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
>> +
>> +#include <linux/err.h>
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/kexec.h>
>> +#include <linux/pe.h>
>> +#include <linux/string.h>
>> +#include <asm/byteorder.h>
>> +#include <asm/image.h>
>> +
>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>> +{
>> +       const struct riscv_image_header *h =
>> +               (const struct riscv_image_header *)(kernel_buf);
>> +
>> +       if (!h || (kernel_len < sizeof(*h)))
>> +               return -EINVAL;
>> +
>> +       /* According to Documentation/riscv/boot-image-header.rst,
>> +        * use "magic2" field to check when version >= 0.2.
>> +        */
>> +
>> +       if (h->version >= RISCV_HEADER_VERSION &&
>> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>> +               return -EINVAL;
>> +
>> +       return 0;
>> +}
>> +
>> +static void *image_load(struct kimage *image,
>> +                               char *kernel, unsigned long kernel_len,
>> +                               char *initrd, unsigned long initrd_len,
>> +                               char *cmdline, unsigned long cmdline_len)
>> +{
>> +       struct riscv_image_header *h;
>> +       u64 flags;
>> +       bool be_image, be_kernel;
>> +       struct kexec_buf kbuf;
>> +       int ret;
>> +
>> +       /* Check Image header */
>> +       h = (struct riscv_image_header *)kernel;
>> +       if (!h->image_size) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       /* Check endianness */
>> +       flags = le64_to_cpu(h->flags);
>> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
>> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>> +       if (be_image != be_kernel) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       /* Load the kernel image */
>> +       kbuf.image = image;
>> +       kbuf.buf_min = 0;
>> +       kbuf.buf_max = ULONG_MAX;
>> +       kbuf.top_down = false;
>> +
>> +       kbuf.buffer = kernel;
>> +       kbuf.bufsz = kernel_len;
>> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>> +       kbuf.memsz = le64_to_cpu(h->image_size);
>> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
>> +
>> +       ret = kexec_add_buffer(&kbuf);
>> +       if (ret) {
>> +               pr_err("Error add kernel image ret=%d\n", ret);
>> +               goto out;
>> +       }
>> +
>> +       image->start = kbuf.mem;
>> +
>> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);
> 
> pr_info() or pr_debug()? >
> 
>> +
>> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>> +                                 initrd, initrd_len, cmdline, cmdline_len);
>> +
>> +out:
>> +       return ret ? ERR_PTR(ret) : NULL;
>> +}
>> +
>> +const struct kexec_file_ops image_kexec_ops = {
>> +       .probe = image_probe,
>> +       .load = image_load,
>> +};
>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>> index aedb8c16a283..5dc700834f1e 100644
>> --- a/arch/riscv/kernel/machine_kexec_file.c
>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>> @@ -17,6 +17,7 @@
>>
>>   const struct kexec_file_ops * const kexec_file_loaders[] = {
>>          &elf_kexec_ops,
>> +       &image_kexec_ops,
>>          NULL
>>   };
>>
>> --
>> 2.20.1
>>
> 
> I tested these two patches. It works when
> CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
> CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
> follows:
> 
> [45.712019] Unknown rela relocation: 34
> [45.712258] Error loading purgatory ret=-8
> 
> How to fix it? >
> Thanks，
> Yunhui
> 
Thanks for your attention to this series and RV kdump/kexec stack.

As you noticed, this series and the kexec-tools RV support patches[1] 
didn't get any positive responses and have been suspended for a few 
months. And I'm now struggling in my own job, so really sorry that I 
have no time to continue these works.

Although that, I would like to reply to your comments in case anyone 
wants to push this series:

Comment1: Why rename elf_kexec.c to kexec_elf.c ？
- s390 uses kexec_{elf,image}.c file names, so I followed it.

Comment2: pr_info() or pr_debug()?
- pr_debug() seems better.

Comment3: Unknown rela relocation: 34

- The CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY was enabled when I posted 
this series, I didn't see this relocation error at that time.

If you want to fix this relocation error, you need to figure out who 
hold the R_RISCV_ADD16 (34), and how it was generated (compiler options 
or other RV kernel configures). This commit 0f5f46a869a5 ("riscv: kexec: 
Remove -fPIE for PURGATORY_CFLAGS") may help.

[1]: 
https://lore.kernel.org/kexec/[e-mail]/

yunhui cui Feb. 20, 2024, 3:09 a.m. UTC | #8

Hi Song Shuai,

On Mon, Feb 19, 2024 at 5:53 PM Song Shuai <[e-mail]> wrote:
>
>
> Hi, yunhui:
>
> 在 2024/2/16 16:54, yunhui cui 写道:
> > Hi Shuai,
> >
> > On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <[e-mail]> wrote:
> >>
> >> This patch creates image_kexec_ops to load Image binary file
> >> for kexec_file_load() syscall.
> >>
> >> Signed-off-by: Song Shuai <[e-mail]>
> >> ---
> >>   arch/riscv/include/asm/image.h         |  2 +
> >>   arch/riscv/include/asm/kexec.h         |  1 +
> >>   arch/riscv/kernel/Makefile             |  2 +-
> >>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>   arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>   5 files changed, 102 insertions(+), 1 deletion(-)
> >>   create mode 100644 arch/riscv/kernel/kexec_image.c
> >>
> >> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >> index e0b319af3681..8927a6ea1127 100644
> >> --- a/arch/riscv/include/asm/image.h
> >> +++ b/arch/riscv/include/asm/image.h
> >> @@ -30,6 +30,8 @@
> >>                                RISCV_HEADER_VERSION_MINOR)
> >>
> >>   #ifndef __ASSEMBLY__
> >> +#define riscv_image_flag_field(flags, field)\
> >> +                              (((flags) >> field##_SHIFT) & field##_MASK)
> >>   /**
> >>    * struct riscv_image_header - riscv kernel image header
> >>    * @code0:             Executable code
> >> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >> index 518825fe4160..b9ee8346cc8c 100644
> >> --- a/arch/riscv/include/asm/kexec.h
> >> +++ b/arch/riscv/include/asm/kexec.h
> >> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>
> >>   #ifdef CONFIG_KEXEC_FILE
> >>   extern const struct kexec_file_ops elf_kexec_ops;
> >> +extern const struct kexec_file_ops image_kexec_ops;
> >>
> >>   struct purgatory_info;
> >>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >> index 1c62c639e875..9ecba3231a36 100644
> >> --- a/arch/riscv/kernel/Makefile
> >> +++ b/arch/riscv/kernel/Makefile
> >> @@ -86,7 +86,7 @@ endif
> >>   obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
> >>   obj-$(CONFIG_KGDB)             += kgdb.o
> >>   obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
> >> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
> >> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
> >>   obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
> >>   obj-$(CONFIG_CRASH_CORE)       += crash_core.o
> >>
> >> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >> new file mode 100644
> >> index 000000000000..b6aa7f59bd53
> >> --- /dev/null
> >> +++ b/arch/riscv/kernel/kexec_image.c
> >> @@ -0,0 +1,97 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * RISC-V Kexec image loader
> >> + *
> >> + */
> >> +
> >> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
> >> +
> >> +#include <linux/err.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/kexec.h>
> >> +#include <linux/pe.h>
> >> +#include <linux/string.h>
> >> +#include <asm/byteorder.h>
> >> +#include <asm/image.h>
> >> +
> >> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >> +{
> >> +       const struct riscv_image_header *h =
> >> +               (const struct riscv_image_header *)(kernel_buf);
> >> +
> >> +       if (!h || (kernel_len < sizeof(*h)))
> >> +               return -EINVAL;
> >> +
> >> +       /* According to Documentation/riscv/boot-image-header.rst,
> >> +        * use "magic2" field to check when version >= 0.2.
> >> +        */
> >> +
> >> +       if (h->version >= RISCV_HEADER_VERSION &&
> >> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >> +               return -EINVAL;
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static void *image_load(struct kimage *image,
> >> +                               char *kernel, unsigned long kernel_len,
> >> +                               char *initrd, unsigned long initrd_len,
> >> +                               char *cmdline, unsigned long cmdline_len)
> >> +{
> >> +       struct riscv_image_header *h;
> >> +       u64 flags;
> >> +       bool be_image, be_kernel;
> >> +       struct kexec_buf kbuf;
> >> +       int ret;
> >> +
> >> +       /* Check Image header */
> >> +       h = (struct riscv_image_header *)kernel;
> >> +       if (!h->image_size) {
> >> +               ret = -EINVAL;
> >> +               goto out;
> >> +       }
> >> +
> >> +       /* Check endianness */
> >> +       flags = le64_to_cpu(h->flags);
> >> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >> +       if (be_image != be_kernel) {
> >> +               ret = -EINVAL;
> >> +               goto out;
> >> +       }
> >> +
> >> +       /* Load the kernel image */
> >> +       kbuf.image = image;
> >> +       kbuf.buf_min = 0;
> >> +       kbuf.buf_max = ULONG_MAX;
> >> +       kbuf.top_down = false;
> >> +
> >> +       kbuf.buffer = kernel;
> >> +       kbuf.bufsz = kernel_len;
> >> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >> +       kbuf.memsz = le64_to_cpu(h->image_size);
> >> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
> >> +
> >> +       ret = kexec_add_buffer(&kbuf);
> >> +       if (ret) {
> >> +               pr_err("Error add kernel image ret=%d\n", ret);
> >> +               goto out;
> >> +       }
> >> +
> >> +       image->start = kbuf.mem;
> >> +
> >> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >
> > pr_info() or pr_debug()? >
> >
> >> +
> >> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >> +                                 initrd, initrd_len, cmdline, cmdline_len);
> >> +
> >> +out:
> >> +       return ret ? ERR_PTR(ret) : NULL;
> >> +}
> >> +
> >> +const struct kexec_file_ops image_kexec_ops = {
> >> +       .probe = image_probe,
> >> +       .load = image_load,
> >> +};
> >> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >> index aedb8c16a283..5dc700834f1e 100644
> >> --- a/arch/riscv/kernel/machine_kexec_file.c
> >> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >> @@ -17,6 +17,7 @@
> >>
> >>   const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>          &elf_kexec_ops,
> >> +       &image_kexec_ops,
> >>          NULL
> >>   };
> >>
> >> --
> >> 2.20.1
> >>
> >
> > I tested these two patches. It works when
> > CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
> > CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
> > follows:
> >
> > [45.712019] Unknown rela relocation: 34
> > [45.712258] Error loading purgatory ret=-8
> >
> > How to fix it? >
> > Thanks，
> > Yunhui
> >
> Thanks for your attention to this series and RV kdump/kexec stack.
>
> As you noticed, this series and the kexec-tools RV support patches[1]
> didn't get any positive responses and have been suspended for a few
> months. And I'm now struggling in my own job, so really sorry that I
> have no time to continue these works.
>
> Although that, I would like to reply to your comments in case anyone
> wants to push this series:
>
> Comment1: Why rename elf_kexec.c to kexec_elf.c ？
> - s390 uses kexec_{elf,image}.c file names, so I followed it.
Okay, so are arm64/x86.

> Comment2: pr_info() or pr_debug()?
> - pr_debug() seems better.
>
> Comment3: Unknown rela relocation: 34
>
> - The CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY was enabled when I posted
> this series, I didn't see this relocation error at that time.
>
> If you want to fix this relocation error, you need to figure out who
> hold the R_RISCV_ADD16 (34), and how it was generated (compiler options
> or other RV kernel configures). This commit 0f5f46a869a5 ("riscv: kexec:
> Remove -fPIE for PURGATORY_CFLAGS") may help.

Have you tested it with the top commit of linux-next? Can you share the .config?

Thanks

Patch

diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
index e0b319af3681..8927a6ea1127 100644
--- a/arch/riscv/include/asm/image.h
+++ b/arch/riscv/include/asm/image.h
@@ -30,6 +30,8 @@ 
 			      RISCV_HEADER_VERSION_MINOR)
 
 #ifndef __ASSEMBLY__
+#define riscv_image_flag_field(flags, field)\
+			       (((flags) >> field##_SHIFT) & field##_MASK)
 /**
  * struct riscv_image_header - riscv kernel image header
  * @code0:		Executable code
diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
index 518825fe4160..b9ee8346cc8c 100644
--- a/arch/riscv/include/asm/kexec.h
+++ b/arch/riscv/include/asm/kexec.h
@@ -56,6 +56,7 @@  extern riscv_kexec_method riscv_kexec_norelocate;
 
 #ifdef CONFIG_KEXEC_FILE
 extern const struct kexec_file_ops elf_kexec_ops;
+extern const struct kexec_file_ops image_kexec_ops;
 
 struct purgatory_info;
 int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 1c62c639e875..9ecba3231a36 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -86,7 +86,7 @@  endif
 obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
 obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
-obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
+obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
 
diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
new file mode 100644
index 000000000000..b6aa7f59bd53
--- /dev/null
+++ b/arch/riscv/kernel/kexec_image.c
@@ -0,0 +1,97 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V Kexec image loader
+ *
+ */
+
+#define pr_fmt(fmt)	"kexec_file(Image): " fmt
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/pe.h>
+#include <linux/string.h>
+#include <asm/byteorder.h>
+#include <asm/image.h>
+
+static int image_probe(const char *kernel_buf, unsigned long kernel_len)
+{
+	const struct riscv_image_header *h =
+		(const struct riscv_image_header *)(kernel_buf);
+
+	if (!h || (kernel_len < sizeof(*h)))
+		return -EINVAL;
+
+	/* According to Documentation/riscv/boot-image-header.rst,
+	 * use "magic2" field to check when version >= 0.2.
+	 */
+
+	if (h->version >= RISCV_HEADER_VERSION &&
+	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void *image_load(struct kimage *image,
+				char *kernel, unsigned long kernel_len,
+				char *initrd, unsigned long initrd_len,
+				char *cmdline, unsigned long cmdline_len)
+{
+	struct riscv_image_header *h;
+	u64 flags;
+	bool be_image, be_kernel;
+	struct kexec_buf kbuf;
+	int ret;
+
+	/* Check Image header */
+	h = (struct riscv_image_header *)kernel;
+	if (!h->image_size) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Check endianness */
+	flags = le64_to_cpu(h->flags);
+	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
+	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
+	if (be_image != be_kernel) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Load the kernel image */
+	kbuf.image = image;
+	kbuf.buf_min = 0;
+	kbuf.buf_max = ULONG_MAX;
+	kbuf.top_down = false;
+
+	kbuf.buffer = kernel;
+	kbuf.bufsz = kernel_len;
+	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+	kbuf.memsz = le64_to_cpu(h->image_size);
+	kbuf.buf_align = le64_to_cpu(h->text_offset);
+
+	ret = kexec_add_buffer(&kbuf);
+	if (ret) {
+		pr_err("Error add kernel image ret=%d\n", ret);
+		goto out;
+	}
+
+	image->start = kbuf.mem;
+
+	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+				kbuf.mem, kbuf.bufsz, kbuf.memsz);
+
+	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
+				  initrd, initrd_len, cmdline, cmdline_len);
+
+out:
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+const struct kexec_file_ops image_kexec_ops = {
+	.probe = image_probe,
+	.load = image_load,
+};
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index aedb8c16a283..5dc700834f1e 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -17,6 +17,7 @@ 
 
 const struct kexec_file_ops * const kexec_file_loaders[] = {
 	&elf_kexec_ops,
+	&image_kexec_ops,
 	NULL
 };