Re: [PATCH v3 02/14] x86/boot: Add missing handling of setup_indirect structures

Jarkko Sakkinen
2021-08-10T16:19:35Z

On Mon, Aug 09, 2021 at 12:38:44PM -0400, Ross Philipson wrote:
> One of the two functions in ioremap.c that handles setup_data was
> missing the correct handling of setup_indirect structures.

What is "correct handling", and how was it broken?

What is 'setup_indirect'?

> Functionality missing from original commit:

Remove this sentence.

> commit b3c72fc9a78e (x86/boot: Introduce setup_indirect)

Should be.

Fixes: b3c72fc9a78e ("x86/boot: Introduce setup_indirect")

> Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
> ---
> arch/x86/mm/ioremap.c | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index ab74e4f..f2b34c5 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c
> @@ -669,17 +669,34 @@ static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
>
> paddr = boot_params.hdr.setup_data;
> while (paddr) {
> - unsigned int len;
> + unsigned int len, size;
>
> if (phys_addr == paddr)
> return true;
>
> data = early_memremap_decrypted(paddr, sizeof(*data));
> + size = sizeof(*data);
>
> paddr_next = data->next;
> len = data->len;
>
> - early_memunmap(data, sizeof(*data));
> + if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
> + early_memunmap(data, sizeof(*data));
> + return true;
> + }
> +
> + if (data->type == SETUP_INDIRECT) {
> + size += len;
> + early_memunmap(data, sizeof(*data));
> + data = early_memremap_decrypted(paddr, size);
> +
> + if (((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
> + paddr = ((struct setup_indirect *)data->data)->addr;
> + len = ((struct setup_indirect *)data->data)->len;
> + }
> + }
> +
> + early_memunmap(data, size);
>
> if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
> return true;
> --
> 1.8.3.1
>
>

/Jarkko