76 lines
		
	
	
	
		
			1.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			76 lines
		
	
	
	
		
			1.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | #include <linux/kernel.h>
 | ||
|  | #include <linux/kprobes.h>
 | ||
|  | #include <linux/stop_machine.h>
 | ||
|  | 
 | ||
|  | #include <asm/cacheflush.h>
 | ||
|  | #include <asm/smp_plat.h>
 | ||
|  | #include <asm/opcodes.h>
 | ||
|  | 
 | ||
|  | #include "patch.h"
 | ||
|  | 
 | ||
|  | struct patch { | ||
|  | 	void *addr; | ||
|  | 	unsigned int insn; | ||
|  | }; | ||
|  | 
 | ||
|  | void __kprobes __patch_text(void *addr, unsigned int insn) | ||
|  | { | ||
|  | 	bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL); | ||
|  | 	int size; | ||
|  | 
 | ||
|  | 	if (thumb2 && __opcode_is_thumb16(insn)) { | ||
|  | 		*(u16 *)addr = __opcode_to_mem_thumb16(insn); | ||
|  | 		size = sizeof(u16); | ||
|  | 	} else if (thumb2 && ((uintptr_t)addr & 2)) { | ||
|  | 		u16 first = __opcode_thumb32_first(insn); | ||
|  | 		u16 second = __opcode_thumb32_second(insn); | ||
|  | 		u16 *addrh = addr; | ||
|  | 
 | ||
|  | 		addrh[0] = __opcode_to_mem_thumb16(first); | ||
|  | 		addrh[1] = __opcode_to_mem_thumb16(second); | ||
|  | 
 | ||
|  | 		size = sizeof(u32); | ||
|  | 	} else { | ||
|  | 		if (thumb2) | ||
|  | 			insn = __opcode_to_mem_thumb32(insn); | ||
|  | 		else | ||
|  | 			insn = __opcode_to_mem_arm(insn); | ||
|  | 
 | ||
|  | 		*(u32 *)addr = insn; | ||
|  | 		size = sizeof(u32); | ||
|  | 	} | ||
|  | 
 | ||
|  | 	flush_icache_range((uintptr_t)(addr), | ||
|  | 			   (uintptr_t)(addr) + size); | ||
|  | } | ||
|  | 
 | ||
|  | static int __kprobes patch_text_stop_machine(void *data) | ||
|  | { | ||
|  | 	struct patch *patch = data; | ||
|  | 
 | ||
|  | 	__patch_text(patch->addr, patch->insn); | ||
|  | 
 | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | void __kprobes patch_text(void *addr, unsigned int insn) | ||
|  | { | ||
|  | 	struct patch patch = { | ||
|  | 		.addr = addr, | ||
|  | 		.insn = insn, | ||
|  | 	}; | ||
|  | 
 | ||
|  | 	if (cache_ops_need_broadcast()) { | ||
|  | 		stop_machine(patch_text_stop_machine, &patch, cpu_online_mask); | ||
|  | 	} else { | ||
|  | 		bool straddles_word = IS_ENABLED(CONFIG_THUMB2_KERNEL) | ||
|  | 				      && __opcode_is_thumb32(insn) | ||
|  | 				      && ((uintptr_t)addr & 2); | ||
|  | 
 | ||
|  | 		if (straddles_word) | ||
|  | 			stop_machine(patch_text_stop_machine, &patch, NULL); | ||
|  | 		else | ||
|  | 			__patch_text(addr, insn); | ||
|  | 	} | ||
|  | } |