[PATCH net-next v4 1/4] mm: add a signature in struct page
From: Matteo Croce <hidden>
Date: 2021-05-11 13:32:49
Also in:
bpf, linux-rdma, lkml, netdev
Subsystem:
memory management - core, networking [general], page pool, the rest · Maintainers:
Andrew Morton, David Hildenbrand, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jesper Dangaard Brouer, Ilias Apalodimas, Linus Torvalds
From: Matteo Croce <redacted> This is needed by the page_pool to avoid recycling a page not allocated via page_pool. Signed-off-by: Matteo Croce <redacted> --- include/linux/mm_types.h | 1 + include/net/page_pool.h | 2 ++ net/core/page_pool.c | 4 ++++ 3 files changed, 7 insertions(+)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 5aacc1c10a45..77c04210e474 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h@@ -101,6 +101,7 @@ struct page { * 32-bit architectures. */ unsigned long dma_addr[2]; + unsigned long signature; }; struct { /* slab, slob and slub */ union {
diff --git a/include/net/page_pool.h b/include/net/page_pool.h
index b4b6de909c93..9814e36becc1 100644
--- a/include/net/page_pool.h
+++ b/include/net/page_pool.h@@ -63,6 +63,8 @@ */ #define PP_ALLOC_CACHE_SIZE 128 #define PP_ALLOC_CACHE_REFILL 64 +#define PP_SIGNATURE 0x20210303 + struct pp_alloc_cache { u32 count; struct page *cache[PP_ALLOC_CACHE_SIZE];
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 3c4c4c7a0402..2e5e2b8c3a02 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c@@ -221,6 +221,8 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool, return NULL; } + page->signature = PP_SIGNATURE; + /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt);
@@ -341,6 +343,8 @@ void page_pool_release_page(struct page_pool *pool, struct page *page) DMA_ATTR_SKIP_CPU_SYNC); page_pool_set_dma_addr(page, 0); skip_dma_unmap: + page->signature = 0; + /* This may be the last page returned, releasing the pool, so * it is not safe to reference pool afterwards. */
--
2.31.1