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-rw-r--r--drivers/net/ethernet/sun/niu.c41
-rw-r--r--scripts/gcc-plugins/randomize_layout_plugin.c2
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" },
{ }