[dpdk-dev] [PATCH v2] log: Properly reset log_history_size in rte_log_dump_history()

[Jan Blunck <jblunck@infradead.org>]

In rte_log_dump_history() the log_history list is reinitialized without
resetting the log_history_size. In the next call to rte_log_add_in_history()
the log_history_size > RTE_LOG_HISTORY and the code unconditionally tries
to remove the first entry:

Program received signal SIGSEGV, Segmentation fault.
rte_log_add_in_history (
    buf=buf@entry=0x7f02035cd000 "DATAPLANE: 9:dp0s7 link RTM_NEWLINK [dp0s7] <UP,BROADCAST,RUNNING,MULTICAST,LOWER_UP>\nCAST,LOWER_UP>\n", size=size@entry=86)
    at /usr/src/packages/BUILD/lib/librte_eal/common/eal_common_log.c:122

Signed-off-by: Jan Blunck <jblunck@infradead.org>
---
 lib/librte_eal/common/eal_common_log.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/eal_common_log.c b/lib/librte_eal/common/eal_common_log.c
index fe3d7d5..39d6e3f 100644
--- a/lib/librte_eal/common/eal_common_log.c
+++ b/lib/librte_eal/common/eal_common_log.c
@@ -119,7 +119,10 @@ rte_log_add_in_history(const char *buf, size_t size)
 	/* get a buffer for adding in history */
 	if (log_history_size > RTE_LOG_HISTORY) {
 		hist_buf = STAILQ_FIRST(&log_history);
-		STAILQ_REMOVE_HEAD(&log_history, next);
+		if (hist_buf) {
+			STAILQ_REMOVE_HEAD(&log_history, next);
+			log_history_size--;
+		}
 	}
 	else {
 		if (rte_mempool_mc_get(log_history_mp, &obj) < 0)
@@ -234,6 +237,7 @@ rte_log_dump_history(FILE *out)
 	rte_spinlock_lock(&log_list_lock);
 	tmp_log_history = log_history;
 	STAILQ_INIT(&log_history);
+	log_history_size = 0;
 	rte_spinlock_unlock(&log_list_lock);
 
 	for (i=0; i<RTE_LOG_HISTORY; i++) {
-- 
2.1.4