Revision 8ad9219e08af12a5652892e273336dbd31b25b03 authored by Stephane Eranian on 17 January 2014, 15:34:06 UTC, committed by Arnaldo Carvalho de Melo on 20 January 2014, 19:19:09 UTC
This patch fixes a memory corruption problem with the xyarray when the evsel fds get closed at the end of the run_perf_stat() call. It could be triggered with: # perf stat -a -e power/energy-cores/ ls When cpumask are used by events (.e.g, RAPL or uncores) then the evsel fds are allocated based on the actual number of CPUs monitored. That number can be smaller than the total number of CPUs on the system. The problem arises at the end by perf stat closes the fds twice. When fds are closed, their entry in the xyarray are set to -1. The first close() on the evsel is made from __run_perf_stat() and it uses the actual number of CPUS for the event which is how the xyarray was allocated for. The second is from perf_evlist_close() but that one is on the total number of CPUs in the system, so it assume the xyarray was allocated to cover it. However it was not, and some writes corrupt memory. The fix is in perf_evlist_close() is to first try with the evsel->cpus if present, if not use the evlist->cpus. That fixes the problem. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389972846-6566-3-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 parent de256a4
loop.c
/*
* Copyright (c) 2006 Oracle. 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/slab.h>
#include <linux/in.h>
#include "rds.h"
#include "loop.h"
static DEFINE_SPINLOCK(loop_conns_lock);
static LIST_HEAD(loop_conns);
/*
* This 'loopback' transport is a special case for flows that originate
* and terminate on the same machine.
*
* Connection build-up notices if the destination address is thought of
* as a local address by a transport. At that time it decides to use the
* loopback transport instead of the bound transport of the sending socket.
*
* The loopback transport's sending path just hands the sent rds_message
* straight to the receiving path via an embedded rds_incoming.
*/
/*
* Usually a message transits both the sender and receiver's conns as it
* flows to the receiver. In the loopback case, though, the receive path
* is handed the sending conn so the sense of the addresses is reversed.
*/
static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
unsigned int hdr_off, unsigned int sg,
unsigned int off)
{
struct scatterlist *sgp = &rm->data.op_sg[sg];
int ret = sizeof(struct rds_header) +
be32_to_cpu(rm->m_inc.i_hdr.h_len);
/* Do not send cong updates to loopback */
if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off);
goto out;
}
BUG_ON(hdr_off || sg || off);
rds_inc_init(&rm->m_inc, conn, conn->c_laddr);
/* For the embedded inc. Matching put is in loop_inc_free() */
rds_message_addref(rm);
rds_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
GFP_KERNEL);
rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence),
NULL);
rds_inc_put(&rm->m_inc);
out:
return ret;
}
/*
* See rds_loop_xmit(). Since our inc is embedded in the rm, we
* make sure the rm lives at least until the inc is done.
*/
static void rds_loop_inc_free(struct rds_incoming *inc)
{
struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
rds_message_put(rm);
}
/* we need to at least give the thread something to succeed */
static int rds_loop_recv(struct rds_connection *conn)
{
return 0;
}
struct rds_loop_connection {
struct list_head loop_node;
struct rds_connection *conn;
};
/*
* Even the loopback transport needs to keep track of its connections,
* so it can call rds_conn_destroy() on them on exit. N.B. there are
* 1+ loopback addresses (127.*.*.*) so it's not a bug to have
* multiple loopback conns allocated, although rather useless.
*/
static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp)
{
struct rds_loop_connection *lc;
unsigned long flags;
lc = kzalloc(sizeof(struct rds_loop_connection), gfp);
if (!lc)
return -ENOMEM;
INIT_LIST_HEAD(&lc->loop_node);
lc->conn = conn;
conn->c_transport_data = lc;
spin_lock_irqsave(&loop_conns_lock, flags);
list_add_tail(&lc->loop_node, &loop_conns);
spin_unlock_irqrestore(&loop_conns_lock, flags);
return 0;
}
static void rds_loop_conn_free(void *arg)
{
struct rds_loop_connection *lc = arg;
unsigned long flags;
rdsdebug("lc %p\n", lc);
spin_lock_irqsave(&loop_conns_lock, flags);
list_del(&lc->loop_node);
spin_unlock_irqrestore(&loop_conns_lock, flags);
kfree(lc);
}
static int rds_loop_conn_connect(struct rds_connection *conn)
{
rds_connect_complete(conn);
return 0;
}
static void rds_loop_conn_shutdown(struct rds_connection *conn)
{
}
void rds_loop_exit(void)
{
struct rds_loop_connection *lc, *_lc;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
spin_lock_irq(&loop_conns_lock);
list_splice(&loop_conns, &tmp_list);
INIT_LIST_HEAD(&loop_conns);
spin_unlock_irq(&loop_conns_lock);
list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {
WARN_ON(lc->conn->c_passive);
rds_conn_destroy(lc->conn);
}
}
/*
* This is missing .xmit_* because loop doesn't go through generic
* rds_send_xmit() and doesn't call rds_recv_incoming(). .listen_stop and
* .laddr_check are missing because transport.c doesn't iterate over
* rds_loop_transport.
*/
struct rds_transport rds_loop_transport = {
.xmit = rds_loop_xmit,
.recv = rds_loop_recv,
.conn_alloc = rds_loop_conn_alloc,
.conn_free = rds_loop_conn_free,
.conn_connect = rds_loop_conn_connect,
.conn_shutdown = rds_loop_conn_shutdown,
.inc_copy_to_user = rds_message_inc_copy_to_user,
.inc_free = rds_loop_inc_free,
.t_name = "loopback",
};
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...