[PATCH v1 05/10] MIPS: add kexec ELF loading support

[Sascha Hauer]

On Wed, May 16, 2018 at 06:42:28PM +0200, Oleksij Rempel wrote:
> From: Antony Pavlov <antonynpavlov at gmail.com>
> 
> Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
> Signed-off-by: Peter Mamonov <pmamonov at gmail.com>
> ---
>  arch/mips/include/asm/elf.h        |   8 +-
>  arch/mips/lib/Makefile             |   4 +
>  arch/mips/lib/kexec-mach-generic.c |  21 +++
>  arch/mips/lib/kexec-mips.c         | 307 +++++++++++++++++++++++++++++++++++++
>  arch/mips/lib/machine_kexec.h      |  21 +++
>  arch/mips/lib/relocate_kernel.S    | 108 +++++++++++++
>  6 files changed, 468 insertions(+), 1 deletion(-)
>  create mode 100644 arch/mips/lib/kexec-mach-generic.c
>  create mode 100644 arch/mips/lib/kexec-mips.c
>  create mode 100644 arch/mips/lib/machine_kexec.h
>  create mode 100644 arch/mips/lib/relocate_kernel.S
> 
> +int kexec_load(struct image_data *data, void *entry,
> +	       unsigned long nr_segments,
> +	       struct kexec_segment *segments)
> +{
> +	int i;
> +	struct resource *elf;
> +	resource_size_t start;
> +	LIST_HEAD(elf_segments);
> +
> +	for (i = 0; i < nr_segments; i++) {
> +		resource_size_t mem = (resource_size_t)segments[i].mem;
> +
> +		elf = create_resource("elf segment",
> +			mem, mem + segments[i].memsz - 1);
> +
> +		list_add_used_region(&elf->sibling, &elf_segments);
> +	}
> +
> +	if (check_room_for_elf(&elf_segments)) {
> +		pr_err("ELF can't be loaded!\n");
> +		return -ENOSPC;
> +	}
> +
> +	start = dcheck_res(&elf_segments);
> +
> +	/* relocate_new_kernel() copy by register (4 or 8 bytes)
> +	   so start address must be aligned to 4/8 */
> +	start = (start + 15) & 0xfffffff0;
> +
> +	for (i = 0; i < nr_segments; i++) {
> +		segments[i].mem = (void *)(phys_to_virt((unsigned long)segments[i].mem));
> +		memcpy(phys_to_virt(start), segments[i].buf, segments[i].bufsz);
> +		request_sdram_region("kexec relocatable segment",
> +			(unsigned long)phys_to_virt(start),
> +			(unsigned long)segments[i].bufsz);

The return value of request_sdram_region should be checked and of course
the resource should be used after having checked the return value, not
before. Same for the other calls to request_sdram_region.

Sascha

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