mempool: Use default poison value when robust is set

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I84a75bd14f6798261fd630aaf076cc3981bad0a1

diff --git a/src/rseq-mempool.c b/src/rseq-mempool.c
index 1562a75a4ea25b404d15707039046dc85792727d..425448449d3db0b1db46627a269200e2208676d1 100644 (file)
--- a/src/rseq-mempool.c
+++ b/src/rseq-mempool.c
@@ -52,6 +52,12 @@
 
 #define RANGE_HEADER_OFFSET    sizeof(struct rseq_mempool_range)
 
+#if RSEQ_BITS_PER_LONG == 64
+# define DEFAULT_POISON_VALUE  0x5555555555555555ULL
+#else
+# define DEFAULT_POISON_VALUE  0x55555555UL
+#endif
+
 struct free_list_node;
 
 struct free_list_node {
@@ -183,7 +189,7 @@ void rseq_percpu_check_poison_item(const struct rseq_mempool *pool,
        uintptr_t poison = pool->attr.poison;
        int i;
 
-       if (!pool->attr.robust_set || !pool->attr.poison_set)
+       if (!pool->attr.robust_set)
                return;
        for (i = 0; i < pool->attr.max_nr_cpus; i++) {
                char *p = __rseq_pool_range_percpu_ptr(range, i,
@@ -389,7 +395,7 @@ void check_pool_poison(const struct rseq_mempool *pool)
 {
        struct rseq_mempool_range *range;
 
-       if (!pool->attr.robust_set || !pool->attr.poison_set)
+       if (!pool->attr.robust_set)
                return;
        for (range = pool->range_list; range; range = range->next)
                check_range_poison(pool, range);
@@ -645,6 +651,10 @@ struct rseq_mempool *rseq_mempool_create(const char *pool_name,
        }
        if (!attr.stride)
                attr.stride = RSEQ_MEMPOOL_STRIDE;      /* Use default */
+       if (attr.robust_set && !attr.poison_set) {
+               attr.poison_set = true;
+               attr.poison = DEFAULT_POISON_VALUE;
+       }
        if (item_len > attr.stride || attr.stride < (size_t) rseq_get_page_len() ||
                        !is_pow2(attr.stride)) {
                errno = EINVAL;