log: fix crash after dump

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 "[snip]\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>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/lib/librte_eal/common/eal_common_log.c b/lib/librte_eal/common/eal_common_log.c
index c903aa9..1ae8de7 100644 (file)
--- 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++) {