Messages in this thread | | | From | "Rusty Lynch" <> | Subject | Re: [PATCH] kprobes for 2.5.47 | Date | Tue, 12 Nov 2002 17:58:39 -0800 |
| |
When register_kprobe() is called with a bad addr, we crash the kernel. Should it be the reponsibility of the caller, or the kernel to make sure the addr is ok?
The kernel could check by adding a
+unsigned short tmp; .... +if(__get_user(tmp, (unsigned short *)p->addr)) { + ret = -EINVAL; + goto out; +}
to register_kprobe()
> +int register_kprobe(struct kprobe *p) > +{ > + int ret = 0; > + > + spin_lock_irq(&kprobe_lock); > + if (get_kprobe(p->addr)) { > + ret = -EEXIST; > + goto out; > + } > + list_add(&p->list, &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); > + > + p->opcode = *p->addr; > + *p->addr = BREAKPOINT_INSTRUCTION; > + flush_icache_range(p->addr, p->addr + sizeof(kprobe_opcode_t)); > + out: > + spin_unlock_irq(&kprobe_lock); > + return ret; > +}
BTW, I have a stupid little sample char driver that reads in address/message pairs and then adds a probe that printk's the message at the address. This was just my way of learning how to use kprobes. Should I post it? I would love to get feedback on what I did wrong, but I hate to spam the list.
-rustyl
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |