Re: [PATCH v3 6/9] module: switch to execmem API for remapping as RW and restoring ROX

On 1/26/25 08:47, Mike Rapoport wrote:

From: "Mike Rapoport (Microsoft)" rppt@kernel.org

Instead of using writable copy for module text sections, temporarily remap the memory allocated from execmem's ROX cache as writable and restore its ROX permissions after the module is formed.

This will allow removing nasty games with writable copy in alternatives patching on x86.

Signed-off-by: Mike Rapoport (Microsoft) rppt@kernel.org

[...]

+static void module_memory_restore_rox(struct module *mod) +{

• for_class_mod_mem_type(type, text) {

• struct module_memory *mem = &mod->mem[type];
  

• if (mem->is_rox)
  

• 	execmem_restore_rox(mem->base, mem->size);
  

• }

+}

Can the execmem_restore_rox() call here fail? I realize that there isn't much that the module loader can do if that happens, but should it be perhaps logged as a warning?