On 1/28/25 11:00, Mike Rapoport wrote:
On Mon, Jan 27, 2025 at 01:50:31PM +0100, Petr Pavlu wrote:
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?
It won't fail at this point. set_memory APIs may fail if they need to split a large page and could not allocate a new page table, but here all the splits were already done at module_memory_alloc() time.
Ok, thanks for the explanation.
Acked-by: Petr Pavlu petr.pavlu@suse.com
-- Petr