diff options
| -rw-r--r-- | src/vlib/trace_funcs.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/src/vlib/trace_funcs.h b/src/vlib/trace_funcs.h index 357079c4e3d..d9d8d7933ee 100644 --- a/src/vlib/trace_funcs.h +++ b/src/vlib/trace_funcs.h @@ -58,7 +58,7 @@ vlib_add_trace_inline (vlib_main_t * vm, { vlib_trace_main_t *tm = &vm->trace_main; vlib_trace_header_t *h; - u32 n_data_words; + u32 n_data_words, trace_index; ASSERT (vnet_trace_placeholder); @@ -83,12 +83,23 @@ vlib_add_trace_inline (vlib_main_t * vm, if (PREDICT_FALSE (!vlib_add_handoff_trace (vm, b))) return vnet_trace_placeholder; - vlib_validate_trace (tm, b); + /* + * there is a small chance of a race condition with 'clear trace' here: if a + * buffer was set to be traced before the 'clear trace' and is still going + * through the graph after the 'clear trace', its trace_index is staled as + * the pool was destroyed. + * The pool may have been re-allocated because of a new traced buffer, and + * the trace_index might be valid by pure (bad) luck. In that case the trace + * will be a mix of both buffer traces, but this should be acceptable. + */ + trace_index = vlib_buffer_get_trace_index (b); + if (PREDICT_FALSE (pool_is_free_index (tm->trace_buffer_pool, trace_index))) + return vnet_trace_placeholder; n_data_bytes = round_pow2 (n_data_bytes, sizeof (h[0])); n_data_words = n_data_bytes / sizeof (h[0]); - vec_add2_aligned (tm->trace_buffer_pool[vlib_buffer_get_trace_index (b)], h, - 1 + n_data_words, sizeof (h[0])); + vec_add2_aligned (tm->trace_buffer_pool[trace_index], h, 1 + n_data_words, + sizeof (h[0])); h->time = vm->cpu_time_last_node_dispatch; h->n_data = n_data_words; |