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kprobes: Warn if the kprobe is reregistered

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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: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2021-02-03 23:59:27 +09:00 committed by Steven Rostedt (VMware)
parent a1320e0c2f
commit 33b1d14668
1 changed files with 8 additions and 5 deletions
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13
kernel/kprobes.c
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@ -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) {