Commit 33b1d146 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

kprobes: Warn if the kprobe is reregistered 

Warn if the kprobe is reregistered, since there must be
a software bug (actively used resource must not be re-registered)
and caller must be fixed.

Link: https://lkml.kernel.org/r/161236436734.194052.4058506306336814476.stgit@devnote2



Acked-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: default avatarAnanth N Mavinakayanahalli <ananth@linux.ibm.com>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent a1320e0c

kernel/kprobes.c

+8 −5
Original line number Diff line number Diff line
@@ -1520,13 +1520,16 @@ static struct kprobe *__get_valid_kprobe(struct kprobe *p) 
	return ap;

}



/* Return error if the kprobe is being re-registered */

static inline int check_kprobe_rereg(struct kprobe *p)

/*

 * Warn and return error if the kprobe is being re-registered since

 * there must be a software bug.

 */

static inline int warn_kprobe_rereg(struct kprobe *p)

{

	int ret = 0;



	mutex_lock(&kprobe_mutex);

	if (__get_valid_kprobe(p))

	if (WARN_ON_ONCE(__get_valid_kprobe(p)))

		ret = -EINVAL;

	mutex_unlock(&kprobe_mutex);
@@ -1614,7 +1617,7 @@ int register_kprobe(struct kprobe *p) 
		return PTR_ERR(addr);

	p->addr = addr;



	ret = check_kprobe_rereg(p);

	ret = warn_kprobe_rereg(p);

	if (ret)

		return ret;
@@ -1995,7 +1998,7 @@ int register_kretprobe(struct kretprobe *rp) 
		return ret;



	/* If only rp->kp.addr is specified, check reregistering kprobes */

	if (rp->kp.addr && check_kprobe_rereg(&rp->kp))

	if (rp->kp.addr && warn_kprobe_rereg(&rp->kp))

		return -EINVAL;



	if (kretprobe_blacklist_size) {