From 71b45bae14be84ab09212c9ded758fa31e31e945 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nicolai=20H=C3=A4hnle?= Date: Mon, 13 May 2019 16:58:07 +0200 Subject: [PATCH] u_dynarray: return 0 on realloc failure and ensure no-op MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We're not very good at handling out-of-memory conditions in general, but this change at least gives the caller the option of handling it gracefully and without memory leaks. This happens to fix an error in out-of-memory handling in i965, which has the following code in brw_bufmgr.c: node = util_dynarray_grow(vma_list, sizeof(struct vma_bucket_node)); if (unlikely(!node)) return 0ull; Previously, allocation failure for util_dynarray_grow wouldn't actually return NULL when the dynarray was previously non-empty. v2: - make util_dynarray_ensure_cap a no-op on failure, add MUST_CHECK attribute - simplify the new capacity calculation: aside from avoiding a useless loop when newcap is very large, this also avoids an infinite loop when newcap is larger than 1 << 31 Reviewed-by: Marek Olšák --- src/util/u_dynarray.h | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/src/util/u_dynarray.h b/src/util/u_dynarray.h index b30fd7b..769c382 100644 --- a/src/util/u_dynarray.h +++ b/src/util/u_dynarray.h @@ -77,21 +77,23 @@ util_dynarray_clear(struct util_dynarray *buf) #define DYN_ARRAY_INITIAL_SIZE 64 -static inline void * +MUST_CHECK static inline void * util_dynarray_ensure_cap(struct util_dynarray *buf, unsigned newcap) { if (newcap > buf->capacity) { - if (buf->capacity == 0) - buf->capacity = DYN_ARRAY_INITIAL_SIZE; - - while (newcap > buf->capacity) - buf->capacity *= 2; + unsigned capacity = MAX3(DYN_ARRAY_INITIAL_SIZE, buf->capacity * 2, newcap); + void *data; if (buf->mem_ctx) { - buf->data = reralloc_size(buf->mem_ctx, buf->data, buf->capacity); + data = reralloc_size(buf->mem_ctx, buf->data, capacity); } else { - buf->data = realloc(buf->data, buf->capacity); + data = realloc(buf->data, capacity); } + if (!data) + return 0; + + buf->data = data; + buf->capacity = capacity; } return (void *)((char *)buf->data + buf->size); -- 2.7.4