Re: [PATCH 1/6] powerpc/code-patching: Implement generic text patching function

Le 16/09/2022 à 08:23, Benjamin Gray a écrit :

  
-static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
+static int patch_text(void *dest, const void *src, size_t size, bool is_exec)
  {
  	int err;
  	unsigned long flags;
  
-	/*
-	 * During early early boot patch_instruction is called
-	 * when text_poke_area is not ready, but we still need
-	 * to allow patching. We just do the plain old patching
-	 */
+	/* Make sure we aren't patching a freed init section */
+	if (static_branch_likely(&init_mem_is_free) && init_section_contains(dest, 4))
+		return 0;
+
  	if (!static_branch_likely(&poking_init_done))
-		return raw_patch_instruction(addr, instr);
+		return __patch_text(dest, src, size, is_exec, dest);
  

Test ordering looks odd. How can init_mem_is_free be true and 
poking_init_done be false ?

  	local_irq_save(flags);
-	err = __do_patch_instruction(addr, instr);
+	err = do_patch_text(dest, src, size, is_exec);
  	local_irq_restore(flags);
  
  	return err;
  }