Hi Ard,

On Fri, 2021-01-15 at 09:30 -0800, Lakshmi Ramasubramanian wrote:
> create_dtb() function allocates kernel virtual memory for
> the device tree blob (DTB).  This is not consistent with other
> architectures, such as powerpc, which calls kmalloc() for allocating
> memory for the DTB.
> 
> Call kmalloc() to allocate memory for the DTB, and kfree() to free
> the allocated memory.

The vmalloc() function description says, "vmalloc - allocate virtually
contiguous memory".  I'd appreciate your reviewing this patch, in
particular, which replaces vmalloc() with kmalloc().

thanks,

Mimi

> 
> Co-developed-by: Prakhar Srivastava <prsr...@linux.microsoft.com>
> Signed-off-by: Prakhar Srivastava <prsr...@linux.microsoft.com>
> Signed-off-by: Lakshmi Ramasubramanian <nra...@linux.microsoft.com>
> ---
>  arch/arm64/kernel/machine_kexec_file.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/kernel/machine_kexec_file.c 
> b/arch/arm64/kernel/machine_kexec_file.c
> index 7de9c47dee7c..51c40143d6fa 100644
> --- a/arch/arm64/kernel/machine_kexec_file.c
> +++ b/arch/arm64/kernel/machine_kexec_file.c
> @@ -29,7 +29,7 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
>  
>  int arch_kimage_file_post_load_cleanup(struct kimage *image)
>  {
> -     vfree(image->arch.dtb);
> +     kfree(image->arch.dtb);
>       image->arch.dtb = NULL;
>  
>       vfree(image->arch.elf_headers);
> @@ -59,19 +59,21 @@ static int create_dtb(struct kimage *image,
>                       + cmdline_len + DTB_EXTRA_SPACE;
>  
>       for (;;) {
> -             buf = vmalloc(buf_size);
> +             buf = kmalloc(buf_size, GFP_KERNEL);
>               if (!buf)
>                       return -ENOMEM;
>  
>               /* duplicate a device tree blob */
>               ret = fdt_open_into(initial_boot_params, buf, buf_size);
> -             if (ret)
> +             if (ret) {
> +                     kfree(buf);
>                       return -EINVAL;
> +             }
>  
>               ret = of_kexec_setup_new_fdt(image, buf, initrd_load_addr,
>                                            initrd_len, cmdline);
>               if (ret) {
> -                     vfree(buf);
> +                     kfree(buf);
>                       if (ret == -ENOMEM) {
>                               /* unlikely, but just in case */
>                               buf_size += DTB_EXTRA_SPACE;
> @@ -217,6 +219,6 @@ int load_other_segments(struct kimage *image,
>       return 0;
>  
>  out_err:
> -     vfree(dtb);
> +     kfree(dtb);
>       return ret;
>  }


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