From: Masami Hiramatsu <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Tom Zanussi <zanussi@kernel.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 2/3] tracing/boottime: Fix kprobe event API usage
Date: Sat, 25 Apr 2020 14:49:17 +0900 [thread overview]
Message-ID: <158779375766.6082.201939936008972838.stgit@devnote2> (raw)
In-Reply-To: <158779373972.6082.16695832932765258919.stgit@devnote2>
Fix boottime kprobe events to use API correctly for
multiple events.
For example, when we set a multiprobe kprobe events in
bootconfig like below,
ftrace.event.kprobes.myevent {
probes = "vfs_read $arg1 $arg2", "vfs_write $arg1 $arg2"
}
This cause an error;
trace_boot: Failed to add probe: p:kprobes/myevent (null) vfs_read $arg1 $arg2 vfs_write $arg1 $arg2
This shows the 1st argument becomes NULL and multiprobes
are merged to 1 probe.
Fixes: 29a154810546 ("tracing: Change trace_boot to use kprobe_event interface")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
---
kernel/trace/trace_boot.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 06d7feb5255f..9de29bb45a27 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -95,24 +95,20 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
struct xbc_node *anode;
char buf[MAX_BUF_LEN];
const char *val;
- int ret;
+ int ret = 0;
- kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+ xbc_node_for_each_array_value(node, "probes", anode, val) {
+ kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
- ret = kprobe_event_gen_cmd_start(&cmd, event, NULL);
- if (ret)
- return ret;
+ ret = kprobe_event_gen_cmd_start(&cmd, event, val);
+ if (ret)
+ break;
- xbc_node_for_each_array_value(node, "probes", anode, val) {
- ret = kprobe_event_add_field(&cmd, val);
+ ret = kprobe_event_gen_cmd_end(&cmd);
if (ret)
- return ret;
+ pr_err("Failed to add probe: %s\n", buf);
}
- ret = kprobe_event_gen_cmd_end(&cmd);
- if (ret)
- pr_err("Failed to add probe: %s\n", buf);
-
return ret;
}
#else
next prev parent reply other threads:[~2020-04-25 5:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-25 5:48 [PATCH 0/3] tracing/kprobes: Fix event generation API etc Masami Hiramatsu
2020-04-25 5:49 ` [PATCH 1/3] tracing/kprobes: Fix a double initialization typo Masami Hiramatsu
2020-04-25 5:49 ` Masami Hiramatsu [this message]
2020-04-25 14:00 ` [PATCH 2/3] tracing/boottime: Fix kprobe event API usage Steven Rostedt
2020-04-26 7:59 ` Masami Hiramatsu
2020-04-26 20:55 ` Tom Zanussi
2020-04-25 5:49 ` [PATCH 3/3] tracing/kprobes: Reject new event if loc is NULL Masami Hiramatsu
2020-05-20 14:22 ` [PATCH 0/3] tracing/kprobes: Fix event generation API etc Masami Hiramatsu
2020-05-20 14:33 ` Steven Rostedt
2020-05-20 14:40 ` Steven Rostedt
2020-05-21 7:55 ` Masami Hiramatsu
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