Commit da0f1f41 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)

tracing/boottime: Fix kprobe event API usage

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.

Link: http://lkml.kernel.org/r/158779375766.6082.201939936008972838.stgit@devnote2

Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 29a15481 ("tracing: Change trace_boot to use kprobe_event interface")
Reviewed-by: default avatarTom Zanussi <zanussi@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent dcbd21c9
...@@ -95,24 +95,20 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event) ...@@ -95,24 +95,20 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
struct xbc_node *anode; struct xbc_node *anode;
char buf[MAX_BUF_LEN]; char buf[MAX_BUF_LEN];
const char *val; 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); ret = kprobe_event_gen_cmd_start(&cmd, event, val);
if (ret) if (ret)
return ret; break;
xbc_node_for_each_array_value(node, "probes", anode, val) { ret = kprobe_event_gen_cmd_end(&cmd);
ret = kprobe_event_add_field(&cmd, val);
if (ret) 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; return ret;
} }
#else #else
......
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