diff options
| -rw-r--r-- | drivers/net/ethernet/sun/niu.c | 41 | ||||
| -rw-r--r-- | scripts/gcc-plugins/randomize_layout_plugin.c | 2 |
2 files changed, 31 insertions, 12 deletions
diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c index 42460c0885fc..df70df29deea 100644 --- a/drivers/net/ethernet/sun/niu.c +++ b/drivers/net/ethernet/sun/niu.c @@ -35,6 +35,25 @@ #include "niu.h" +/* This driver wants to store a link to a "next page" within the + * page struct itself by overloading the content of the "mapping" + * member. This is not expected by the page API, but does currently + * work. However, the randstruct plugin gets very bothered by this + * case because "mapping" (struct address_space) is randomized, so + * casts to/from it trigger warnings. Hide this by way of a union, + * to create a typed alias of "mapping", since that's how it is + * actually being used here. + */ +union niu_page { + struct page page; + struct { + unsigned long __flags; /* unused alias of "flags" */ + struct list_head __lru; /* unused alias of "lru" */ + struct page *next; /* alias of "mapping" */ + }; +}; +#define niu_next_page(p) container_of(p, union niu_page, page)->next + #define DRV_MODULE_NAME "niu" #define DRV_MODULE_VERSION "1.1" #define DRV_MODULE_RELDATE "Apr 22, 2010" @@ -3283,7 +3302,7 @@ static struct page *niu_find_rxpage(struct rx_ring_info *rp, u64 addr, addr &= PAGE_MASK; pp = &rp->rxhash[h]; - for (; (p = *pp) != NULL; pp = (struct page **) &p->mapping) { + for (; (p = *pp) != NULL; pp = &niu_next_page(p)) { if (p->index == addr) { *link = pp; goto found; @@ -3300,7 +3319,7 @@ static void niu_hash_page(struct rx_ring_info *rp, struct page *page, u64 base) unsigned int h = niu_hash_rxaddr(rp, base); page->index = base; - page->mapping = (struct address_space *) rp->rxhash[h]; + niu_next_page(page) = rp->rxhash[h]; rp->rxhash[h] = page; } @@ -3382,11 +3401,11 @@ static int niu_rx_pkt_ignore(struct niu *np, struct rx_ring_info *rp) rcr_size = rp->rbr_sizes[(val & RCR_ENTRY_PKTBUFSZ) >> RCR_ENTRY_PKTBUFSZ_SHIFT]; if ((page->index + PAGE_SIZE) - rcr_size == addr) { - *link = (struct page *) page->mapping; + *link = niu_next_page(page); np->ops->unmap_page(np->device, page->index, PAGE_SIZE, DMA_FROM_DEVICE); page->index = 0; - page->mapping = NULL; + niu_next_page(page) = NULL; __free_page(page); rp->rbr_refill_pending++; } @@ -3451,11 +3470,11 @@ static int niu_process_rx_pkt(struct napi_struct *napi, struct niu *np, niu_rx_skb_append(skb, page, off, append_size, rcr_size); if ((page->index + rp->rbr_block_size) - rcr_size == addr) { - *link = (struct page *) page->mapping; + *link = niu_next_page(page); np->ops->unmap_page(np->device, page->index, PAGE_SIZE, DMA_FROM_DEVICE); page->index = 0; - page->mapping = NULL; + niu_next_page(page) = NULL; rp->rbr_refill_pending++; } else get_page(page); @@ -3518,13 +3537,13 @@ static void niu_rbr_free(struct niu *np, struct rx_ring_info *rp) page = rp->rxhash[i]; while (page) { - struct page *next = (struct page *) page->mapping; + struct page *next = niu_next_page(page); u64 base = page->index; np->ops->unmap_page(np->device, base, PAGE_SIZE, DMA_FROM_DEVICE); page->index = 0; - page->mapping = NULL; + niu_next_page(page) = NULL; __free_page(page); @@ -6440,8 +6459,7 @@ static void niu_reset_buffers(struct niu *np) page = rp->rxhash[j]; while (page) { - struct page *next = - (struct page *) page->mapping; + struct page *next = niu_next_page(page); u64 base = page->index; base = base >> RBR_DESCR_ADDR_SHIFT; rp->rbr[k++] = cpu_to_le32(base); @@ -10176,6 +10194,9 @@ static int __init niu_init(void) BUILD_BUG_ON(PAGE_SIZE < 4 * 1024); + BUILD_BUG_ON(offsetof(struct page, mapping) != + offsetof(union niu_page, next)); + niu_debug = netif_msg_init(debug, NIU_MSG_DEFAULT); #ifdef CONFIG_SPARC64 diff --git a/scripts/gcc-plugins/randomize_layout_plugin.c b/scripts/gcc-plugins/randomize_layout_plugin.c index 5836a7fc7532..c9d345a91c41 100644 --- a/scripts/gcc-plugins/randomize_layout_plugin.c +++ b/scripts/gcc-plugins/randomize_layout_plugin.c @@ -46,8 +46,6 @@ struct whitelist_entry { }; static const struct whitelist_entry whitelist[] = { - /* NIU overloads mapping with page struct */ - { "drivers/net/ethernet/sun/niu.c", "page", "address_space" }, /* unix_skb_parms via UNIXCB() buffer */ { "net/unix/af_unix.c", "unix_skb_parms", "char" }, { } |