On 06.06.2023 21:55, Oleksii Kurochko wrote:
> Signed-off-by: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
Such commits without description are worrying. This may be okay for
entirely trivial and obvious changes, but that's going to be the
exception.
> --- a/xen/arch/riscv/xen.lds.S
> +++ b/xen/arch/riscv/xen.lds.S
> @@ -20,6 +20,7 @@ SECTIONS
> . = XEN_VIRT_START;
> _start = .;
> .text : {
> + _idmap_start = .;
> _stext = .; /* Text section */
> *(.text.header)
>
> @@ -35,6 +36,7 @@ SECTIONS
> *(.gnu.warning)
> . = ALIGN(POINTER_ALIGN);
> _etext = .; /* End of text section */
> + _idmap_end = .;
> } :text
So this covers all of .text. Why is it expected that .text will be (and
remain) ...
> @@ -174,3 +176,10 @@ ASSERT(!SIZEOF(.got), ".got non-empty")
> ASSERT(!SIZEOF(.got.plt), ".got.plt non-empty")
>
> ASSERT(_end - _start <= MB(2), "Xen too large for early-boot assumptions")
> +
> +/*
> + * We require that Xen is loaded at a page boundary, so this ensures that any
> + * code running on the identity map cannot cross a page boundary.
> + */
> +ASSERT(IS_ALIGNED(_idmap_start, PAGE_SIZE), "_idmap_start should be
> page-aligned")
> +ASSERT(_idmap_end - _idmap_start <= PAGE_SIZE, "Identity mapped code is
> larger than a page size")
... less than 4k in size? And why is only .text of interest, but not
other sections?
I find the other assertion a little puzzling too: Isn't that merely
checking that XEN_VIRT_START is page aligned?
Jan
