From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Michael Ellerman <mpe@ellerman.id.au>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 1/2] trace/kprobes: Sanitize derived event names
Date: Thu, 22 Jun 2017 00:20:27 +0530 [thread overview]
Message-ID: <22e10dfa9457c28e0ffeaec3a4a7161ef23196fa.1498070485.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1498070485.git.naveen.n.rao@linux.vnet.ibm.com>
In-Reply-To: <cover.1498070485.git.naveen.n.rao@linux.vnet.ibm.com>
When we derive event names, convert some expected symbols (such as ':'
used to specify module:name and '.' present in some symbols) into
underscores so that the event name is not rejected.
Before this patch:
# echo 'p kobject_example:foo_store' > kprobe_events
trace_kprobe: Failed to allocate trace_probe.(-22)
-sh: write error: Invalid argument
After this patch:
# echo 'p kobject_example:foo_store' > kprobe_events
# cat kprobe_events
p:kprobes/p_kobject_example_foo_store_0 kobject_example:foo_store
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
kernel/trace/trace_kprobe.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c129fca6ec99..44fd819aa33d 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -598,6 +598,14 @@ static struct notifier_block trace_kprobe_module_nb = {
.priority = 1 /* Invoked after kprobe module callback */
};
+/* Convert certain expected symbols into '_' when generating event names */
+static inline void sanitize_event_name(char *name)
+{
+ while (*name++ != '\0')
+ if (*name == ':' || *name == '.')
+ *name = '_';
+}
+
static int create_trace_kprobe(int argc, char **argv)
{
/*
@@ -740,6 +748,7 @@ static int create_trace_kprobe(int argc, char **argv)
else
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
is_return ? 'r' : 'p', addr);
+ sanitize_event_name(buf);
event = buf;
}
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
--
2.13.1
next prev parent reply other threads:[~2017-06-21 18:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-21 18:50 [PATCH 0/2] A couple of small updates/fixes for kprobes tracer Naveen N. Rao
2017-06-21 18:50 ` Naveen N. Rao [this message]
2017-06-22 9:29 ` [PATCH 1/2] trace/kprobes: Sanitize derived event names Masami Hiramatsu
2017-06-22 19:03 ` Naveen N. Rao
2017-06-23 17:30 ` Masami Hiramatsu
2017-06-21 18:50 ` [PATCH 2/2] selftests/ftrace: Update multiple kprobes test for powerpc Naveen N. Rao
2017-06-22 9:07 ` Masami Hiramatsu
2017-06-22 17:03 ` Naveen N. Rao
2017-06-23 17:30 ` Masami Hiramatsu
2017-06-24 11:06 ` Masami Hiramatsu
2017-06-28 9:28 ` Naveen N. Rao
2017-06-28 14:16 ` Masami Hiramatsu
2017-06-28 18:43 ` Naveen N. Rao
2017-06-29 0:57 ` Masami Hiramatsu
2017-06-29 13:08 ` Naveen N. Rao
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