+++ Josh Poimboeuf [14/04/20 11:28 -0500]:
With arch_klp_init_object_loaded() gone, and apply_relocate_add() now
using text_poke(), livepatch no longer needs to use module_disable_ro().
The text_mutex usage can also be removed -- its purpose was to protect
against module permission change races.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
kernel/livepatch/core.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 817676caddee..3a88639b3326 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -767,10 +767,6 @@ static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_modinfo *info = patch->mod->klp_info;
if (klp_is_module(obj)) {
-
- mutex_lock(&text_mutex);
- module_disable_ro(patch->mod);
-
Don't you still need the text_mutex to use text_poke() though?
(Through klp_write_relocations -> apply_relocate_add -> text_poke)
At least, I see this assertion there:
void *text_poke(void *addr, const void *opcode, size_t len)
{
lockdep_assert_held(&text_mutex);
return __text_poke(addr, opcode, len);
}
Jessica
