b43: Rewrite TX bounce buffer handling
Do not mess with the original skb, but allocate an independent bouncebuffer.
This protects against bad interference with mac80211's assumptions about
the skb (which already caused bugs).
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index de4e804..b5cd7f5 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -1157,18 +1157,17 @@
}
static int dma_tx_fragment(struct b43_dmaring *ring,
- struct sk_buff **in_skb)
+ struct sk_buff *skb)
{
- struct sk_buff *skb = *in_skb;
const struct b43_dma_ops *ops = ring->ops;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct b43_private_tx_info *priv_info = b43_get_priv_tx_info(info);
u8 *header;
int slot, old_top_slot, old_used_slots;
int err;
struct b43_dmadesc_generic *desc;
struct b43_dmadesc_meta *meta;
struct b43_dmadesc_meta *meta_hdr;
- struct sk_buff *bounce_skb;
u16 cookie;
size_t hdrsize = b43_txhdr_size(ring->dev);
@@ -1212,34 +1211,28 @@
meta->skb = skb;
meta->is_last_fragment = 1;
+ priv_info->bouncebuffer = NULL;
meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
/* create a bounce buffer in zone_dma on mapping failure. */
if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
- bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
- if (!bounce_skb) {
+ priv_info->bouncebuffer = kmalloc(skb->len, GFP_ATOMIC | GFP_DMA);
+ if (!priv_info->bouncebuffer) {
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
err = -ENOMEM;
goto out_unmap_hdr;
}
+ memcpy(priv_info->bouncebuffer, skb->data, skb->len);
- memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
- memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
- bounce_skb->dev = skb->dev;
- skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
- info = IEEE80211_SKB_CB(bounce_skb);
-
- dev_kfree_skb_any(skb);
- skb = bounce_skb;
- *in_skb = bounce_skb;
- meta->skb = skb;
- meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
+ meta->dmaaddr = map_descbuffer(ring, priv_info->bouncebuffer, skb->len, 1);
if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
+ kfree(priv_info->bouncebuffer);
+ priv_info->bouncebuffer = NULL;
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
err = -EIO;
- goto out_free_bounce;
+ goto out_unmap_hdr;
}
}
@@ -1256,8 +1249,6 @@
ops->poke_tx(ring, next_slot(ring, slot));
return 0;
-out_free_bounce:
- dev_kfree_skb_any(skb);
out_unmap_hdr:
unmap_descbuffer(ring, meta_hdr->dmaaddr,
hdrsize, 1);
@@ -1362,11 +1353,7 @@
* static, so we don't need to store it per frame. */
ring->queue_prio = skb_get_queue_mapping(skb);
- /* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
- * into the skb data or cb now. */
- hdr = NULL;
- info = NULL;
- err = dma_tx_fragment(ring, &skb);
+ err = dma_tx_fragment(ring, skb);
if (unlikely(err == -ENOKEY)) {
/* Drop this packet, as we don't have the encryption key
* anymore and must not transmit it unencrypted. */
@@ -1413,12 +1400,17 @@
B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
desc = ops->idx2desc(ring, slot, &meta);
- if (meta->skb)
- unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
- 1);
- else
+ if (meta->skb) {
+ struct b43_private_tx_info *priv_info =
+ b43_get_priv_tx_info(IEEE80211_SKB_CB(meta->skb));
+
+ unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len, 1);
+ kfree(priv_info->bouncebuffer);
+ priv_info->bouncebuffer = NULL;
+ } else {
unmap_descbuffer(ring, meta->dmaaddr,
b43_txhdr_size(dev), 1);
+ }
if (meta->is_last_fragment) {
struct ieee80211_tx_info *info;
diff --git a/drivers/net/wireless/b43/xmit.h b/drivers/net/wireless/b43/xmit.h
index 3530de8..d23ff9f 100644
--- a/drivers/net/wireless/b43/xmit.h
+++ b/drivers/net/wireless/b43/xmit.h
@@ -2,6 +2,8 @@
#define B43_XMIT_H_
#include "main.h"
+#include <net/mac80211.h>
+
#define _b43_declare_plcp_hdr(size) \
struct b43_plcp_hdr##size { \
@@ -332,4 +334,21 @@
return raw_kidx;
}
+/* struct b43_private_tx_info - TX info private to b43.
+ * The structure is placed in (struct ieee80211_tx_info *)->rate_driver_data
+ *
+ * @bouncebuffer: DMA Bouncebuffer (if used)
+ */
+struct b43_private_tx_info {
+ void *bouncebuffer;
+};
+
+static inline struct b43_private_tx_info *
+b43_get_priv_tx_info(struct ieee80211_tx_info *info)
+{
+ BUILD_BUG_ON(sizeof(struct b43_private_tx_info) >
+ sizeof(info->rate_driver_data));
+ return (struct b43_private_tx_info *)info->rate_driver_data;
+}
+
#endif /* B43_XMIT_H_ */