Update: Herbert's patch alters the arguments to alloc_skb_fclone() and skb_reserve() from within sk_stream_alloc_pskb(). This changes the skb_headroom() and skb_tailroom() of the returned skb. I decided to see if I could detect the precise point at which data corruption started to happen. The result is this table:
(sk_stream_alloc_pskb() called with size == 1448; sk->sk_prot->max_header == 160) skb_headroom skb_tailroom test result note 216 1448 fail [1] 344 1448 fail 340 1452 pass 336 1456 pass 332 1460 pass 328 1464 fail 324 1468 pass 320 1472 pass 316 1476 pass 312 1480 fail 308 1484 pass 304 1488 pass 300 1492 pass 296 1496 fail 292 1500 pass 288 1504 pass 284 1508 pass 280 1512 fail 276 1516 pass 272 1520 pass 268 1524 pass 264 1528 fail 260 1532 pass 256 1536 pass [2] Notes: [1] Kernels 2.6.23.4 - 2.6.23.16 and 2.6.24 - current with Herbert's patch [2] Kernels 2.6.23.3 and before without Herbert's patch Note that the first row has skb_headroom + skb_tailroom == 1664; the remaining rows have skb_headroom + skb_tailroom == 1792. >From these results, it looks like a data alignment issue. Herbert's patch unfortunately just happened to change the alignment in a way that made it break. Tony -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
