From: "Steven Rostedt (Red Hat)" Add a enum that denotes the last bit of the trace_flags and have a BUILD_BUG_ON(last_bit > 32). If we add more bits than we have in trace_flags, the kernel wont build. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 ++++++ kernel/trace/trace.h | 6 +++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7446d4238f87..991bab9b79d2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7046,6 +7046,12 @@ __init static int tracer_alloc_buffers(void) int ring_buf_size; int ret = -ENOMEM; + /* + * Make sure we don't accidently add more trace options + * than we have bits for. + */ + BUILD_BUG_ON(TRACE_ITER_LAST_BIT > 32); + if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) goto out; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 8ed97872b65b..07155652254d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -966,7 +966,11 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, #undef C #define C(a, b) TRACE_ITER_##a##_BIT -enum trace_iterator_bits { TRACE_FLAGS }; +enum trace_iterator_bits { + TRACE_FLAGS + /* Make sure we don't go more than we have bits for */ + TRACE_ITER_LAST_BIT +}; /* * By redefining C, we can make TRACE_FLAGS a list of masks that -- 2.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/