From 49e23849a5262affd8580ee515eabf65d2e06b12 Mon Sep 17 00:00:00 2001 From: Max Wash Date: Thu, 2 Feb 2023 16:45:13 +0000 Subject: [PATCH] sandbox: queue: check list is not empty before popping entries --- sandbox/queue/include/socks/queue.h | 3 ++- sandbox/queue/queue.c | 17 +++++++++++++++-- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/sandbox/queue/include/socks/queue.h b/sandbox/queue/include/socks/queue.h index 77f0c96..741837d 100644 --- a/sandbox/queue/include/socks/queue.h +++ b/sandbox/queue/include/socks/queue.h @@ -5,7 +5,8 @@ #define QUEUE_CONTAINER(t, m, v) ((void *)((v) ? (uintptr_t)(v) - (offsetof(t, m)) : 0)) -#define QUEUE_INIT ((queue_t){ .q_first = NULL, .q_last = NULL, .q_length = 0}) +#define QUEUE_INIT ((queue_t){ .q_first = NULL, .q_last = NULL, .q_length = 0 }) +#define QUEUE_ENTRY_INIT ((queue_entry_t){ .qe_next = NULL, .qe_prev = NULL }) #define queue_foreach(iter_type, iter_name, queue_name, node_member) \ for (iter_type *iter_name = QUEUE_CONTAINER(iter_type, node_member, queue_first(queue_name)); \ diff --git a/sandbox/queue/queue.c b/sandbox/queue/queue.c index cf3ac8d..c8a468a 100644 --- a/sandbox/queue/queue.c +++ b/sandbox/queue/queue.c @@ -1,4 +1,6 @@ #include +#include +#include void queue_insert_before(queue_t *q, queue_entry_t *entry, queue_entry_t *before) { @@ -70,19 +72,30 @@ void queue_push_back(queue_t *q, queue_entry_t *entry) queue_entry_t *queue_pop_front(queue_t *q) { queue_entry_t *x = q->q_first; - queue_delete(q, x); + if (x) { + queue_delete(q, x); + } + return x; } queue_entry_t *queue_pop_back(queue_t *q) { queue_entry_t *x = q->q_last; - queue_delete(q, x); + if (x) { + queue_delete(q, x); + } + return x; } void queue_delete(queue_t *q, queue_entry_t *entry) { + if (!entry) { + printf("null entry\n"); + return; + } + if (entry == q->q_first) { q->q_first = q->q_first->qe_next; }