From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>
Cc: Alban Crequy <alban.crequy@gmail.com>,
Alban Crequy <alban@kinvolk.io>,
Alexei Starovoitov <ast@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Omar Sandoval <osandov@fb.com>,
linux-doc@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, iago@kinvolk.io,
michael@kinvolk.io, Dorau Lukasz <lukasz.dorau@intel.com>,
systemtap@sourceware.org
Subject: [RFC PATCH tip/master 3/3] kprobes: Limit kretprobe maximum instances
Date: Wed, 29 Mar 2017 14:24:23 +0900 [thread overview]
Message-ID: <149076505311.24574.3646383930433662308.stgit@devbox> (raw)
In-Reply-To: <149076484118.24574.7083269903420611708.stgit@devbox>
Limit kretprobe maximum instance up to MAXACTIVE_ALLOC.
Without this limit, kretprobe user can specify huge number
(e.g. forget to zero-fill struct kretprobe) to maxactive
and may cause out-of-memory.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/kprobes.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 75c5390..f1bebcf 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1942,6 +1942,9 @@ int register_kretprobe(struct kretprobe *rp)
rp->kp.break_handler = NULL;
/* Pre-allocate memory for max kretprobe instances */
+ if (rp->maxactive > KRETPROBE_MAXACTIVE_ALLOC)
+ return -E2BIG;
+
if (rp->maxactive <= 0) {
#ifdef CONFIG_PREEMPT
rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus());
next prev parent reply other threads:[~2017-03-29 5:24 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-29 5:20 [RFC PATCH tip/master 0/3] kprobes: tracing: kretprobe_instance dynamic allocation Masami Hiramatsu
2017-03-29 5:22 ` [RFC PATCH tip/master 1/3] trace: kprobes: Show sum of probe/retprobe nmissed count Masami Hiramatsu
2017-03-31 9:45 ` Alban Crequy
2017-03-29 5:23 ` [RFC PATCH tip/master 2/3] kprobes: Allocate kretprobe instance if its free list is empty Masami Hiramatsu
2017-03-29 6:30 ` Ingo Molnar
2017-03-29 8:25 ` Masami Hiramatsu
2017-03-29 17:18 ` Josh Stone
2017-03-30 0:39 ` Masami Hiramatsu
2017-03-30 6:53 ` Ingo Molnar
2017-03-30 13:01 ` Masami Hiramatsu
2017-04-12 6:42 ` Ingo Molnar
2017-03-30 13:03 ` Alban Crequy
2017-03-29 5:24 ` Masami Hiramatsu [this message]
2017-03-29 13:27 ` [RFC PATCH tip/master 0/3] kprobes: tracing: kretprobe_instance dynamic allocation Frank Ch. Eigler
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