| Message ID | CAAM7YAkB3VVNMmBMVuvEZuV6oGZeyog37_sjFGUunu+15apvZA@mail.gmail.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On Sat, 03 Sep 2011 20:30:19 +0800, "Yan, Zheng " said: > The skb can be destructed before the while loop in unix_stream_sendmsg stops. > please try below patch. Tried this on top of next-20110831, and system is up and running fine. Feel free to stick this on it: Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e6d9d10..f6d7ed7 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1577,6 +1577,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, int sent = 0; struct scm_cookie tmp_scm; bool fds_sent = false; + bool scm_ref = true; int max_level;
The skb can be destructed before the while loop in unix_stream_sendmsg stops. please try below patch. --- if (NULL == siocb->scm) @@ -1637,12 +1638,19 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, */ size = min_t(int, size, skb_tailroom(skb)); + /* + * pass the scm reference to the skb if a single skb is large + * enough to hold all data. + */ + if (!fds_sent && sent + size >= len) + scm_ref = false; - /* Only send the fds and no ref to pid in the first buffer */ - err = unix_scm_to_skb(siocb->scm, skb, !fds_sent, fds_sent); + /* Only send the fds in the first buffer */ + err = unix_scm_to_skb(siocb->scm, skb, !fds_sent, + fds_sent || scm_ref); if (err < 0) { kfree_skb(skb); - goto out; + goto out_err; } max_level = err + 1; fds_sent = true; @@ -1650,7 +1658,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); if (err) { kfree_skb(skb); - goto out; + goto out_err; } unix_state_lock(other); @@ -1667,10 +1675,10 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, sent += size; } - if (skb) - scm_release(siocb->scm); - else + if (scm_ref) scm_destroy(siocb->scm); + else + scm_release(siocb->scm); siocb->scm = NULL; return sent; @@ -1683,9 +1691,10 @@ pipe_err: send_sig(SIGPIPE, current, 0); err = -EPIPE; out_err: - if (skb == NULL) + if (scm_ref) scm_destroy(siocb->scm); -out: + else + scm_release(siocb->scm); siocb->scm = NULL; return sent ? : err; } On Sat, Sep 3, 2011 at 2:23 PM, Jiri Slaby <jirislaby@gmail.com> wrote: > On 09/03/2011 07:54 AM, Sedat Dilek wrote: >> >> I saw similiar call-traces with put_cred_rcu() - besides with >> kmem_cache_alloc_trace(). >> My post-it says: >> Kernel panic - not syncing: CRED: put_cred_rcu sees f67ac0c0 with usage >> -43 > > Hm, Tim, it looks like you put a pid which you did not get? > > regards, > -- > js > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html