diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index a05524fa245..f64fbaae781 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -648,6 +648,9 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ * char raw_data[__entry_size]; <- allocate our sample in the stack * struct trace_entry *ent; * + * zero dead bytes from alignment to avoid stack leak to userspace: + * + * *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL; * entry = (struct ftrace_raw_ *)raw_data; * ent = &entry->ent; * tracing_generic_entry_update(ent, irq_flags, pc); @@ -698,6 +701,7 @@ static void ftrace_profile_##call(proto) \ char raw_data[__entry_size]; \ struct trace_entry *ent; \ \ + *(u64 *)(&raw_data[__entry_size - sizeof(u64)]) = 0ULL; \ entry = (struct ftrace_raw_##call *)raw_data; \ ent = &entry->ent; \ tracing_generic_entry_update(ent, irq_flags, pc); \