lkml.org 
[lkml]   [2017]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 10/14] arm64: kexec_file: load initrd, device-tree and purgatory segments
On Thu, Aug 24, 2017 at 05:18:07PM +0900, AKASHI Takahiro wrote:
> load_other_segments() sets up and adds all the memory segments necessary
> other than kernel, including initrd, device-tree blob and purgatory.
> Most of the code was borrowed from kexec-tools' counterpart.
>
> In addition, arch_kexec_image_probe(), arch_kexec_image_load() and
> arch_kexec_kernel_verify_sig() are stubs for supporting multiple types
> of kernel image formats.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
> arch/arm64/include/asm/kexec.h | 18 +++
> arch/arm64/kernel/machine_kexec_file.c | 255 +++++++++++++++++++++++++++++++++
> 2 files changed, 273 insertions(+)

> +int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
> + char *initrd, unsigned long initrd_len,
> + char *cmdline, unsigned long cmdline_len)
> +{
> + struct kexec_buf kbuf;
> + unsigned long initrd_load_addr = 0;
> + unsigned long purgatory_load_addr, dtb_load_addr;
> + char *dtb = NULL;
> + unsigned long dtb_len;
> + int ret = 0;
> +
> + kbuf.image = image;
> +
> + /* Load initrd */
> + if (initrd) {
> + kbuf.buffer = initrd;
> + kbuf.bufsz = initrd_len;
> + kbuf.memsz = initrd_len;
> + kbuf.buf_align = PAGE_SIZE;
> + /* within 1GB-aligned window of up to 32GB in size */
> + kbuf.buf_min = kernel_load_addr;
> + kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
> + + (unsigned long)SZ_1G * 31;
> + kbuf.top_down = 0;
> +
> + ret = kexec_add_buffer(&kbuf);
> + if (ret)
> + goto out_err;
> + initrd_load_addr = kbuf.mem;
> +
> + pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> + initrd_load_addr, initrd_len, initrd_len);
> + }
> +
> + /* Load dtb blob */
> + ret = setup_dtb(image, initrd_load_addr, initrd_len,
> + cmdline, cmdline_len, &dtb, &dtb_len);
> + if (ret) {
> + pr_err("Preparing for new dtb failed\n");
> + goto out_err;
> + }
> +
> + kbuf.buffer = dtb;
> + kbuf.bufsz = dtb_len;
> + kbuf.memsz = dtb_len;
> + /* not across 2MB boundary */
> + kbuf.buf_align = SZ_2M;
> + /*
> + * Note for backporting:
> + * On kernel prior to v4.2, fdt must reside within 512MB block
> + * where the kernel also resides. So
> + * kbuf.buf_min = round_down(kernel_load_addr, SZ_512M);
> + * kbuf.buf_max = round_up(kernel_load_addr, SZ_512M);
> + * would be required.
> + */
> + kbuf.buf_min = kernel_load_addr;
> + kbuf.buf_max = ULONG_MAX;
> + kbuf.top_down = 1;

IIUC, this is trying to load the DTB above the kernel. Is that correct?

Assuming so, shouldn't that kernel_load_addr be kernel_load_addr +
image_size from the kernel header?

Otherwise, if the kernel is loaded close to the end of memory, the DTB
could overlap.

Thanks,
Mark.

\
 
 \ /
  Last update: 2017-08-24 19:13    [W:0.454 / U:0.688 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site