trace/kprobes: Add back warning about offset in return probes

Let's not remove the warning about offsets and return probes when the
offset is invalid.

Signed-off-by: Steven Rostedt <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Acked-by: Naveen N. Rao <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 18775ef182f8..2b7d0dd938ba 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -695,6 +695,11 @@ static int create_trace_kprobe(int argc, char **argv)
 			pr_info("Failed to parse symbol.\n");
 			return ret;
 		}
+		if (offset && is_return &&
+		    !arch_function_offset_within_entry(offset)) {
+			pr_info("Given offset is not valid for return probe.\n");
+			return -EINVAL;
+		}
 	}
 	argc -= 2; argv += 2;