diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2020-04-19 20:03:05 -0400 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2020-04-20 10:44:01 -0400 |
| commit | bdb2ce82818577ba6e57b7d68b698b8d17329281 (patch) | |
| tree | 951e3fdca0873b24e24553fa297a6f49d2722f46 | |
| parent | 58bd6656f808c5a8efbe903af3c013595935d50d (diff) | |
| download | linux-bdb2ce82818577ba6e57b7d68b698b8d17329281.tar.bz2 | |
xprtrdma: Fix trace point use-after-free race
It's not safe to use resources pointed to by the @send_wr of
ib_post_send() _after_ that function returns. Those resources are
typically freed by the Send completion handler, which can run before
ib_post_send() returns.
Thus the trace points currently around ib_post_send() in the
client's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.
Fixes: ab03eff58eb5 ("xprtrdma: Add trace points in RPC Call transmit paths")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| -rw-r--r-- | include/trace/events/rpcrdma.h | 12 | ||||
| -rw-r--r-- | net/sunrpc/xprtrdma/verbs.c | 2 |
2 files changed, 5 insertions, 9 deletions
diff --git a/include/trace/events/rpcrdma.h b/include/trace/events/rpcrdma.h index 051f26fedc4d..72f043876019 100644 --- a/include/trace/events/rpcrdma.h +++ b/include/trace/events/rpcrdma.h @@ -692,11 +692,10 @@ TRACE_EVENT(xprtrdma_prepsend_failed, TRACE_EVENT(xprtrdma_post_send, TP_PROTO( - const struct rpcrdma_req *req, - int status + const struct rpcrdma_req *req ), - TP_ARGS(req, status), + TP_ARGS(req), TP_STRUCT__entry( __field(const void *, req) @@ -705,7 +704,6 @@ TRACE_EVENT(xprtrdma_post_send, __field(unsigned int, client_id) __field(int, num_sge) __field(int, signaled) - __field(int, status) ), TP_fast_assign( @@ -718,15 +716,13 @@ TRACE_EVENT(xprtrdma_post_send, __entry->sc = req->rl_sendctx; __entry->num_sge = req->rl_wr.num_sge; __entry->signaled = req->rl_wr.send_flags & IB_SEND_SIGNALED; - __entry->status = status; ), - TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %sstatus=%d", + TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %s", __entry->task_id, __entry->client_id, __entry->req, __entry->sc, __entry->num_sge, (__entry->num_sge == 1 ? "" : "s"), - (__entry->signaled ? "signaled " : ""), - __entry->status + (__entry->signaled ? "signaled" : "") ) ); diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 29ae982d69cf..05c4d3a9cda2 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1356,8 +1356,8 @@ int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) --ep->re_send_count; } + trace_xprtrdma_post_send(req); rc = frwr_send(r_xprt, req); - trace_xprtrdma_post_send(req, rc); if (rc) return -ENOTCONN; return 0; |