tracing/probe: Verify alloc_trace_*probe() result

Since alloc_trace_*probe() returns -EINVAL only if !event && !group,
it should not happen in trace_*probe_create(). If we catch that case
there is a bug. So use WARN_ON_ONCE() instead of pr_info().

Link: http://lkml.kernel.org/r/155253785078.14922.16902223633734601469.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

2 files changed, 4 insertions, 3 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 5265117ad7e8..63aa0ab56051 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -693,9 +693,9 @@ static int trace_kprobe_create(int argc, const char *argv[])
         tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
                                argc, is_return);
         if (IS_ERR(tk)) {
-                pr_info("Failed to allocate trace_probe.(%d)\n",
-                        (int)PTR_ERR(tk));
                 ret = PTR_ERR(tk);
+                /* This must return -ENOMEM otherwise there is a bug */
+                WARN_ON_ONCE(ret != -ENOMEM);
                 goto out;
         }
 
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 52f033489377..b54137ec7810 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -514,8 +514,9 @@ static int trace_uprobe_create(int argc, const char **argv)
 
         tu = alloc_trace_uprobe(group, event, argc, is_return);
         if (IS_ERR(tu)) {
-                pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
                 ret = PTR_ERR(tu);
+                /* This must return -ENOMEM otherwise there is a bug */
+                WARN_ON_ONCE(ret != -ENOMEM);
                 goto fail_address_parse;
         }
         tu->offset = offset;