diff options
author | Hariprasad S <hariprasad@chelsio.com> | 2016-05-06 22:18:07 +0530 |
---|---|---|
committer | Doug Ledford <dledford@redhat.com> | 2016-05-13 19:38:09 -0400 |
commit | f86fac79afecb41682886785364b15cb13f22280 (patch) | |
tree | bc99d51ce1c3419ea9e559e4f7428e0f811a4191 | |
parent | e8667a9b35c550e3daf4519058a52252bf41d9db (diff) | |
download | op-kernel-dev-f86fac79afecb41682886785364b15cb13f22280.zip op-kernel-dev-f86fac79afecb41682886785364b15cb13f22280.tar.gz |
RDMA/iw_cxgb4: atomic find and reference for listening endpoints
Add get_ep_from_stid() which will atomically find and reference the
endpoint struct if found. This avoids touch-after-free races between
threads destroying listening endpoints and the CPL processing thread
processing an incoming PASS_ACCEPT_REQ CPL.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
-rw-r--r-- | drivers/infiniband/hw/cxgb4/cm.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index e8edfee..4ee1054 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -342,6 +342,23 @@ static struct c4iw_ep *get_ep_from_tid(struct c4iw_dev *dev, unsigned int tid) return ep; } +/* + * Atomically lookup the ep ptr given the stid and grab a reference on the ep. + */ +static struct c4iw_listen_ep *get_ep_from_stid(struct c4iw_dev *dev, + unsigned int stid) +{ + struct c4iw_listen_ep *ep; + unsigned long flags; + + spin_lock_irqsave(&dev->lock, flags); + ep = idr_find(&dev->stid_idr, stid); + if (ep) + c4iw_get_ep(&ep->com); + spin_unlock_irqrestore(&dev->lock, flags); + return ep; +} + void _c4iw_free_ep(struct kref *kref) { struct c4iw_ep *ep; @@ -2306,9 +2323,8 @@ fail: static int pass_open_rpl(struct c4iw_dev *dev, struct sk_buff *skb) { struct cpl_pass_open_rpl *rpl = cplhdr(skb); - struct tid_info *t = dev->rdev.lldi.tids; unsigned int stid = GET_TID(rpl); - struct c4iw_listen_ep *ep = lookup_stid(t, stid); + struct c4iw_listen_ep *ep = get_ep_from_stid(dev, stid); if (!ep) { PDBG("%s stid %d lookup failure!\n", __func__, stid); @@ -2317,7 +2333,7 @@ static int pass_open_rpl(struct c4iw_dev *dev, struct sk_buff *skb) PDBG("%s ep %p status %d error %d\n", __func__, ep, rpl->status, status2errno(rpl->status)); c4iw_wake_up(&ep->com.wr_wait, status2errno(rpl->status)); - + c4iw_put_ep(&ep->com); out: return 0; } @@ -2325,12 +2341,12 @@ out: static int close_listsrv_rpl(struct c4iw_dev *dev, struct sk_buff *skb) { struct cpl_close_listsvr_rpl *rpl = cplhdr(skb); - struct tid_info *t = dev->rdev.lldi.tids; unsigned int stid = GET_TID(rpl); - struct c4iw_listen_ep *ep = lookup_stid(t, stid); + struct c4iw_listen_ep *ep = get_ep_from_stid(dev, stid); PDBG("%s ep %p\n", __func__, ep); c4iw_wake_up(&ep->com.wr_wait, status2errno(rpl->status)); + c4iw_put_ep(&ep->com); return 0; } @@ -2490,7 +2506,7 @@ static int pass_accept_req(struct c4iw_dev *dev, struct sk_buff *skb) unsigned short hdrs; u8 tos = PASS_OPEN_TOS_G(ntohl(req->tos_stid)); - parent_ep = lookup_stid(t, stid); + parent_ep = (struct c4iw_ep *)get_ep_from_stid(dev, stid); if (!parent_ep) { PDBG("%s connect request on invalid stid %d\n", __func__, stid); goto reject; @@ -2618,6 +2634,8 @@ static int pass_accept_req(struct c4iw_dev *dev, struct sk_buff *skb) goto out; reject: reject_cr(dev, hwtid, skb); + if (parent_ep) + c4iw_put_ep(&parent_ep->com); out: return 0; } @@ -3868,7 +3886,7 @@ static int rx_pkt(struct c4iw_dev *dev, struct sk_buff *skb) struct cpl_pass_accept_req *req = (void *)(rss + 1); struct l2t_entry *e; struct dst_entry *dst; - struct c4iw_ep *lep; + struct c4iw_ep *lep = NULL; u16 window; struct port_info *pi; struct net_device *pdev; @@ -3893,7 +3911,7 @@ static int rx_pkt(struct c4iw_dev *dev, struct sk_buff *skb) */ stid = (__force int) cpu_to_be32((__force u32) rss->hash_val); - lep = (struct c4iw_ep *)lookup_stid(dev->rdev.lldi.tids, stid); + lep = (struct c4iw_ep *)get_ep_from_stid(dev, stid); if (!lep) { PDBG("%s connect request on invalid stid %d\n", __func__, stid); goto reject; @@ -3994,6 +4012,8 @@ static int rx_pkt(struct c4iw_dev *dev, struct sk_buff *skb) free_dst: dst_release(dst); reject: + if (lep) + c4iw_put_ep(&lep->com); return 0; } |