提交 2dc3a69d 编写于 作者: C Chuck Lever 提交者: Anna Schumaker

xprtrdma: Remove ALLPHYSICAL memory registration mode

No HCA or RNIC in the kernel tree requires the use of ALLPHYSICAL.

ALLPHYSICAL advertises in the clear on the network fabric an R_key
that is good for all of the client's memory. No known exploit
exists, but theoretically any user on the server can use that R_key
on the client's QP to read or update any part of the client's memory.

ALLPHYSICAL exposes the client to server bugs, including:
 o base/bounds errors causing data outside the i/o buffer to be
   accessed
 o RDMA access after reply causing data corruption and/or integrity
   fail

ALLPHYSICAL can't protect application memory regions from server
update after a local signal or soft timeout has terminated an RPC.

ALLPHYSICAL chunks are no larger than a page. Special cases to
handle small chunks and long chunk lists have been a source of
implementation complexity and bugs.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
上级 42fe28f6
obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o
rpcrdma-y := transport.o rpc_rdma.o verbs.o \
fmr_ops.o frwr_ops.o physical_ops.o \
fmr_ops.o frwr_ops.o \
svc_rdma.o svc_rdma_backchannel.o svc_rdma_transport.o \
svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \
module.o
......
/*
* Copyright (c) 2015 Oracle. All rights reserved.
* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
*/
/* No-op chunk preparation. All client memory is pre-registered.
* Sometimes referred to as ALLPHYSICAL mode.
*
* Physical registration is simple because all client memory is
* pre-registered and never deregistered. This mode is good for
* adapter bring up, but is considered not safe: the server is
* trusted not to abuse its access to client memory not involved
* in RDMA I/O.
*/
#include "xprt_rdma.h"
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
static int
physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
struct rpcrdma_create_data_internal *cdata)
{
struct ib_mr *mr;
/* Obtain an rkey to use for RPC data payloads.
*/
mr = ib_get_dma_mr(ia->ri_pd,
IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);
if (IS_ERR(mr)) {
pr_err("%s: ib_get_dma_mr for failed with %lX\n",
__func__, PTR_ERR(mr));
return -ENOMEM;
}
ia->ri_dma_mr = mr;
rpcrdma_set_max_header_sizes(ia, cdata, min_t(unsigned int,
RPCRDMA_MAX_DATA_SEGS,
RPCRDMA_MAX_HDR_SEGS));
return 0;
}
/* PHYSICAL memory registration conveys one page per chunk segment.
*/
static size_t
physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
RPCRDMA_MAX_HDR_SEGS);
}
static int
physical_op_init(struct rpcrdma_xprt *r_xprt)
{
return 0;
}
/* The client's physical memory is already exposed for
* remote access via RDMA READ or RDMA WRITE.
*/
static int
physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
int nsegs, bool writing)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
seg->mr_rkey = ia->ri_dma_mr->rkey;
seg->mr_base = seg->mr_dma;
return 1;
}
/* DMA unmap all memory regions that were mapped for "req".
*/
static void
physical_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
{
struct ib_device *device = r_xprt->rx_ia.ri_device;
unsigned int i;
for (i = 0; req->rl_nchunks; --req->rl_nchunks)
rpcrdma_unmap_one(device, &req->rl_segments[i++]);
}
/* Use a slow, safe mechanism to invalidate all memory regions
* that were registered for "req".
*
* For physical memory registration, there is no good way to
* fence a single MR that has been advertised to the server. The
* client has already handed the server an R_key that cannot be
* invalidated and is shared by all MRs on this connection.
* Tearing down the PD might be the only safe choice, but it's
* not clear that a freshly acquired DMA R_key would be different
* than the one used by the PD that was just destroyed.
* FIXME.
*/
static void
physical_op_unmap_safe(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
bool sync)
{
physical_op_unmap_sync(r_xprt, req);
}
static void
physical_op_destroy(struct rpcrdma_buffer *buf)
{
}
const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
.ro_map = physical_op_map,
.ro_unmap_sync = physical_op_unmap_sync,
.ro_unmap_safe = physical_op_unmap_safe,
.ro_open = physical_op_open,
.ro_maxpages = physical_op_maxpages,
.ro_init = physical_op_init,
.ro_destroy = physical_op_destroy,
.ro_displayname = "physical",
};
......@@ -379,8 +379,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
struct rpcrdma_ia *ia = &xprt->rx_ia;
int rc;
ia->ri_dma_mr = NULL;
ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
if (IS_ERR(ia->ri_id)) {
rc = PTR_ERR(ia->ri_id);
......@@ -418,9 +416,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
case RPCRDMA_FRMR:
ia->ri_ops = &rpcrdma_frwr_memreg_ops;
break;
case RPCRDMA_ALLPHYSICAL:
ia->ri_ops = &rpcrdma_physical_memreg_ops;
break;
case RPCRDMA_MTHCAFMR:
ia->ri_ops = &rpcrdma_fmr_memreg_ops;
break;
......@@ -585,8 +580,6 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
out2:
ib_free_cq(sendcq);
out1:
if (ia->ri_dma_mr)
ib_dereg_mr(ia->ri_dma_mr);
return rc;
}
......@@ -600,8 +593,6 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
void
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
int rc;
dprintk("RPC: %s: entering, connected is %d\n",
__func__, ep->rep_connected);
......@@ -615,12 +606,6 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
ib_free_cq(ep->rep_attr.recv_cq);
ib_free_cq(ep->rep_attr.send_cq);
if (ia->ri_dma_mr) {
rc = ib_dereg_mr(ia->ri_dma_mr);
dprintk("RPC: %s: ib_dereg_mr returned %i\n",
__func__, rc);
}
}
/*
......
......@@ -68,7 +68,6 @@ struct rpcrdma_ia {
struct ib_device *ri_device;
struct rdma_cm_id *ri_id;
struct ib_pd *ri_pd;
struct ib_mr *ri_dma_mr;
struct completion ri_done;
int ri_async_rc;
unsigned int ri_max_frmr_depth;
......@@ -269,8 +268,7 @@ struct rpcrdma_mw {
* NOTES:
* o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
* marshal. The number needed varies depending on the iov lists that
* are passed to us, the memory registration mode we are in, and if
* physical addressing is used, the layout.
* are passed to us and the memory registration mode we are in.
*/
struct rpcrdma_mr_seg { /* chunk descriptors */
......@@ -417,7 +415,6 @@ struct rpcrdma_memreg_ops {
extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
/*
* RPCRDMA transport -- encapsulates the structures above for
......
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