From 33b1d14668859626bf96958e38042b0ed8a22a68 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 3 Feb 2021 23:59:27 +0900 Subject: [PATCH] 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: Naveen N. Rao Acked-by: Ananth N Mavinakayanahalli Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/kprobes.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d5a3eb74a657..dd1d027455c4 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1520,13 +1520,16 @@ valid: 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) { -- 2.20.1