From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: mhiramat@kernel.org, Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: [ftrace/kprobes PATCH 2/3] tracing/kprobes: Check the probe on unloaded module correctly
Date: Wed, 29 Aug 2018 01:18:15 +0900 [thread overview]
Message-ID: <153547309528.26502.8300278470528281328.stgit@devbox> (raw)
In-Reply-To: <153547303754.26502.5265242979168613920.stgit@devbox>
Current kprobe event doesn't checks correctly whether the
given event is on unloaded module or not. It just checks
the event has ":" in the name.
That is not enough because if we define a probe on non-exist
symbol on loaded module, it allows to define that (with
warning message)
To ensure it correctly, this searches the module name on
loaded module list and only if there is not, it allows to
define it. (this event will be available when the target
module is loaded)
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_kprobe.c | 39 ++++++++++++++++++++++++++-------------
1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index b006aaeceb92..fbf609cbeac2 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -62,9 +62,23 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
return strncmp(mod->name, name, len) == 0 && name[len] == ':';
}
-static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
+static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
{
- return !!strchr(trace_kprobe_symbol(tk), ':');
+ char *p;
+ bool ret;
+
+ if (!tk->symbol)
+ return false;
+ p = strchr(tk->symbol, ':');
+ if (!p)
+ return true;
+ *p = '\0';
+ mutex_lock(&module_mutex);
+ ret = !!find_module(tk->symbol);
+ mutex_unlock(&module_mutex);
+ *p = ':';
+
+ return ret;
}
static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
@@ -374,19 +388,13 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
else
ret = register_kprobe(&tk->rp.kp);
- if (ret == 0)
+ if (ret == 0) {
tk->tp.flags |= TP_FLAG_REGISTERED;
- else {
- if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
- pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
- ret = 0;
- } else if (ret == -EILSEQ) {
- pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
- tk->rp.kp.addr);
- ret = -EINVAL;
- }
+ } else if (ret == -EILSEQ) {
+ pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
+ tk->rp.kp.addr);
+ ret = -EINVAL;
}
-
return ret;
}
@@ -449,6 +457,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
/* Register k*probe */
ret = __register_trace_kprobe(tk);
+ if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
+ pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
+ ret = 0;
+ }
+
if (ret < 0)
unregister_kprobe_event(tk);
else
next prev parent reply other threads:[~2018-08-28 16:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-28 16:17 [ftrace/kprobes PATCH 0/3] tracing: probeevent: Fix module symbol probing Masami Hiramatsu
2018-08-28 16:17 ` [ftrace/kprobes PATCH 1/3] tracing/uprobes: Fix to return -EFAULT if copy_from_user failed Masami Hiramatsu
2018-08-28 16:18 ` Masami Hiramatsu [this message]
2018-08-28 16:18 ` [ftrace/kprobes PATCH 3/3] tracing/kprobes: Allow kprobe-events to record module symbol Masami Hiramatsu
2018-10-03 19:12 ` Steven Rostedt
2018-10-04 1:11 ` Steven Rostedt
2018-10-05 8:53 ` Masami Hiramatsu
2018-09-27 10:48 ` [ftrace/kprobes PATCH 0/3] tracing: probeevent: Fix module symbol probing Masami Hiramatsu
2018-10-01 15:48 ` Steven Rostedt
2018-10-03 2:47 ` Steven Rostedt
2018-10-03 13:26 ` Masami Hiramatsu
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