On 19.03.2025 11:46, Jan Beulich wrote: > On 19.03.2025 11:32, Jan Beulich wrote: >> On 18.03.2025 18:35, Roger Pau Monne wrote: >>> Relocations are now applied after having moved the trampoline, >> >> That's two entirely different sets of relocations, isn't it? What we generate >> here is what is to be encoded in the PE binary's .reloc section, for the PE >> loader to process. And for us to then process again once we move Xen back to >> its linked position (by virtue of leaving physical mode). Therefore what >> matters here is whether these relocations are still carried out while on the >> page tables to boot loader created, or when already on page tables we >> control. >> In the former case any relocation to a non-writable section would be liable >> to fault when applied. > > And yes - both calls to efi_arch_relocate_image() are ahead of switching page > tables. The first call is benign - no writes occur there. The second call > would cause #PF though for any relocs applied to .text or .rodata or > .init.text > or whatever else is non-writable.
Ah, no - .rodata is unaffected, due to it being writable as a result of also containing all .data.ro_after_init contributions. Jan
