Revision 92a8109e4d3a34fb6b115c9098b51767dc933444 authored by Ross Lagerwall on 08 January 2019, 18:30:56 UTC, committed by Steve French on 11 January 2019, 13:14:40 UTC
The code tries to allocate a contiguous buffer with a size supplied by the server (maxBuf). This could fail if memory is fragmented since it results in high order allocations for commonly used server implementations. It is also wasteful since there are probably few locks in the usual case. Limit the buffer to be no larger than a page to avoid memory allocation failures due to fragmentation. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Steve French <stfrench@microsoft.com>
1 parent 15bc77f
transport.c
/*
* Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/in.h>
#include <linux/ipv6.h>
#include "rds.h"
#include "loop.h"
static struct rds_transport *transports[RDS_TRANS_COUNT];
static DECLARE_RWSEM(rds_trans_sem);
void rds_trans_register(struct rds_transport *trans)
{
BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ);
down_write(&rds_trans_sem);
if (transports[trans->t_type])
printk(KERN_ERR "RDS Transport type %d already registered\n",
trans->t_type);
else {
transports[trans->t_type] = trans;
printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
}
up_write(&rds_trans_sem);
}
EXPORT_SYMBOL_GPL(rds_trans_register);
void rds_trans_unregister(struct rds_transport *trans)
{
down_write(&rds_trans_sem);
transports[trans->t_type] = NULL;
printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
up_write(&rds_trans_sem);
}
EXPORT_SYMBOL_GPL(rds_trans_unregister);
void rds_trans_put(struct rds_transport *trans)
{
if (trans)
module_put(trans->t_owner);
}
struct rds_transport *rds_trans_get_preferred(struct net *net,
const struct in6_addr *addr,
__u32 scope_id)
{
struct rds_transport *ret = NULL;
struct rds_transport *trans;
unsigned int i;
if (ipv6_addr_v4mapped(addr)) {
if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET)
return &rds_loop_transport;
} else if (ipv6_addr_loopback(addr)) {
return &rds_loop_transport;
}
down_read(&rds_trans_sem);
for (i = 0; i < RDS_TRANS_COUNT; i++) {
trans = transports[i];
if (trans && (trans->laddr_check(net, addr, scope_id) == 0) &&
(!trans->t_owner || try_module_get(trans->t_owner))) {
ret = trans;
break;
}
}
up_read(&rds_trans_sem);
return ret;
}
struct rds_transport *rds_trans_get(int t_type)
{
struct rds_transport *ret = NULL;
struct rds_transport *trans;
unsigned int i;
down_read(&rds_trans_sem);
for (i = 0; i < RDS_TRANS_COUNT; i++) {
trans = transports[i];
if (trans && trans->t_type == t_type &&
(!trans->t_owner || try_module_get(trans->t_owner))) {
ret = trans;
break;
}
}
up_read(&rds_trans_sem);
return ret;
}
/*
* This returns the number of stats entries in the snapshot and only
* copies them using the iter if there is enough space for them. The
* caller passes in the global stats so that we can size and copy while
* holding the lock.
*/
unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
unsigned int avail)
{
struct rds_transport *trans;
unsigned int total = 0;
unsigned int part;
int i;
rds_info_iter_unmap(iter);
down_read(&rds_trans_sem);
for (i = 0; i < RDS_TRANS_COUNT; i++) {
trans = transports[i];
if (!trans || !trans->stats_info_copy)
continue;
part = trans->stats_info_copy(iter, avail);
avail -= min(avail, part);
total += part;
}
up_read(&rds_trans_sem);
return total;
}
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