Chen, Kenneth W wrote:
Mao, Bibo wrote on Wednesday, November 01, 2006 7:12 PM@@ -463,7 +469,10 @@ void __kprobes arch_arm_kprobe(struct kp flush_icache_range((unsigned long)p->ainsn.insn, (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); - memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t)); + if (ATOMIC_UPDATE) + kprobe_update_bundle((void *)arm_addr, (void *)&p->opcode); + else + memcpy((char *)arm_addr, &p->opcode, sizeof(kprobe_opcode_t)); flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t)); }Now comments on the code: why memcpy in the else statement? In the earlier part of the patch, you already reject kprobe address on slot 1 if CPU doesn't have 16-byte memory operation. Why do you allow memcpy here? Will the "else" condition ever be executed?
else means that current cpu does not support 16 byte atomic operation. If kprobe address is on slot 0/2, then memcpy still can execute. thanksbibo,mao -
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