Commit 950fd0db authored by Benjamin Gwin's avatar Benjamin Gwin Committed by Greg Kroah-Hartman
Browse files

arm64: kexec_file: try more regions if loading segments fails 



[ Upstream commit 108aa503 ]

It's possible that the first region picked for the new kernel will make
it impossible to fit the other segments in the required 32GB window,
especially if we have a very large initrd.

Instead of giving up, we can keep testing other regions for the kernel
until we find one that works.

Suggested-by: default avatarRyan O'Leary <ryanoleary@google.com>
Signed-off-by: default avatarBenjamin Gwin <bgwin@google.com>
Link: https://lore.kernel.org/r/20201103201106.2397844-1-bgwin@google.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f3c3bb3b

arch/arm64/kernel/kexec_image.c

+31 −10
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ static void *image_load(struct kimage *image, 
	u64 flags, value;

	bool be_image, be_kernel;

	struct kexec_buf kbuf;

	unsigned long text_offset;

	unsigned long text_offset, kernel_segment_number;

	struct kexec_segment *kernel_segment;

	int ret;
@@ -88,11 +88,37 @@ static void *image_load(struct kimage *image, 
	/* Adjust kernel segment with TEXT_OFFSET */

	kbuf.memsz += text_offset;



	ret = kexec_add_buffer(&kbuf);

	if (ret)

	kernel_segment_number = image->nr_segments;



	/*

	 * The location of the kernel segment may make it impossible to satisfy

	 * the other segment requirements, so we try repeatedly to find a

	 * location that will work.

	 */

	while ((ret = kexec_add_buffer(&kbuf)) == 0) {

		/* Try to load additional data */

		kernel_segment = &image->segment[kernel_segment_number];

		ret = load_other_segments(image, kernel_segment->mem,

					  kernel_segment->memsz, initrd,

					  initrd_len, cmdline);

		if (!ret)

			break;



		/*

		 * We couldn't find space for the other segments; erase the

		 * kernel segment and try the next available hole.

		 */

		image->nr_segments -= 1;

		kbuf.buf_min = kernel_segment->mem + kernel_segment->memsz;

		kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;

	}



	if (ret) {

		pr_err("Could not find any suitable kernel location!");

		return ERR_PTR(ret);

	}



	kernel_segment = &image->segment[image->nr_segments - 1];

	kernel_segment = &image->segment[kernel_segment_number];

	kernel_segment->mem += text_offset;

	kernel_segment->memsz -= text_offset;

	image->start = kernel_segment->mem;
@@ -101,12 +127,7 @@ static void *image_load(struct kimage *image, 
				kernel_segment->mem, kbuf.bufsz,

				kernel_segment->memsz);



	/* Load additional data */

	ret = load_other_segments(image,

				kernel_segment->mem, kernel_segment->memsz,

				initrd, initrd_len, cmdline);



	return ERR_PTR(ret);

	return 0;

}



#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG

arch/arm64/kernel/machine_kexec_file.c

+8 −1
Original line number Diff line number Diff line
@@ -242,6 +242,11 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) 
	return ret;

}



/*

 * Tries to add the initrd and DTB to the image. If it is not possible to find

 * valid locations, this function will undo changes to the image and return non

 * zero.

 */

int load_other_segments(struct kimage *image,

			unsigned long kernel_load_addr,

			unsigned long kernel_size,
@@ -250,7 +255,8 @@ int load_other_segments(struct kimage *image, 
{

	struct kexec_buf kbuf;

	void *headers, *dtb = NULL;

	unsigned long headers_sz, initrd_load_addr = 0, dtb_len;

	unsigned long headers_sz, initrd_load_addr = 0, dtb_len,

		      orig_segments = image->nr_segments;

	int ret = 0;



	kbuf.image = image;
@@ -336,6 +342,7 @@ int load_other_segments(struct kimage *image, 
	return 0;



out_err:

	image->nr_segments = orig_segments;

	vfree(dtb);

	return ret;

}