From 4173cc8e23c19d9b901750413c790a1292b3f5fc Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Fri, 30 Aug 2019 06:03:09 -0400 Subject: ospfd: Do not turn on write thread unless we have something in it I am rarely seeing this crash: r2: ospfd crashed. Core file found - Backtrace follows: [New LWP 32748] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1". Core was generated by `/usr/lib/frr/ospfd'. Program terminated with signal SIGABRT, Aborted. 2019-08-29 15:59:36,149 ERROR: assert failed at "test_ospf_sr_topo1/test_memory_leak": Which translates to this code: node = listhead(ospf->oi_write_q); assert(node); oi = listgetdata(node); assert(oi); So if we get into ospf_write without anything on the oi_write_q we are stopping the program. This is happening because in ospf_ls_upd_queue_send we are calling ospf_write. Imagine that we have a interface already on the on_write_q and then ospf_write handles the packet send for all functions. We are not clearing the t_write thread and we are popping and causing a crash. Additionally modify OSPF_ISM_WRITE_ON(O) to not just blindly turn on the t_write thread. Only do so if we have data. Signed-off-by: Donald Sharp ospfd: Remove redundant asserts assert(oi) is impossible all listgetdata(node) directly proceeding it already asserts here, besides a node cannot be created with a null pointer! If list_isempty is called directly before the listhead call it is impossilbe that we do not have a valid pointer here. Signed-off-by: Donald Sharp --- ospfd/ospf_ism.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'ospfd/ospf_ism.h') diff --git a/ospfd/ospf_ism.h b/ospfd/ospf_ism.h index 5ae99ab32..8d2140369 100644 --- a/ospfd/ospf_ism.h +++ b/ospfd/ospf_ism.h @@ -53,8 +53,9 @@ listnode_add((O)->oi_write_q, oi); \ oi->on_write_q = 1; \ } \ - thread_add_write(master, ospf_write, (O), (O)->fd, \ - &(O)->t_write); \ + if (!list_isempty((O)->oi_write_q)) \ + thread_add_write(master, ospf_write, (O), (O)->fd, \ + &(O)->t_write); \ } while (0) /* Macro for OSPF ISM timer turn on. */ -- cgit v1.2.3