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>
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ax25_dev.c
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/spinlock.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>
ax25_dev *ax25_dev_list;
DEFINE_SPINLOCK(ax25_dev_lock);
ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
{
ax25_dev *ax25_dev, *res = NULL;
spin_lock_bh(&ax25_dev_lock);
for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
res = ax25_dev;
}
spin_unlock_bh(&ax25_dev_lock);
return res;
}
/*
* This is called when an interface is brought up. These are
* reasonable defaults.
*/
void ax25_dev_device_up(struct net_device *dev)
{
ax25_dev *ax25_dev;
if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
return;
}
dev->ax25_ptr = ax25_dev;
ax25_dev->dev = dev;
dev_hold(dev);
ax25_dev->forward = NULL;
ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
ax25_dev->values[AX25_VALUES_BACKOFF] = AX25_DEF_BACKOFF;
ax25_dev->values[AX25_VALUES_CONMODE] = AX25_DEF_CONMODE;
ax25_dev->values[AX25_VALUES_WINDOW] = AX25_DEF_WINDOW;
ax25_dev->values[AX25_VALUES_EWINDOW] = AX25_DEF_EWINDOW;
ax25_dev->values[AX25_VALUES_T1] = AX25_DEF_T1;
ax25_dev->values[AX25_VALUES_T2] = AX25_DEF_T2;
ax25_dev->values[AX25_VALUES_T3] = AX25_DEF_T3;
ax25_dev->values[AX25_VALUES_IDLE] = AX25_DEF_IDLE;
ax25_dev->values[AX25_VALUES_N2] = AX25_DEF_N2;
ax25_dev->values[AX25_VALUES_PACLEN] = AX25_DEF_PACLEN;
ax25_dev->values[AX25_VALUES_PROTOCOL] = AX25_DEF_PROTOCOL;
ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
#if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
ax25_ds_setup_timer(ax25_dev);
#endif
spin_lock_bh(&ax25_dev_lock);
ax25_dev->next = ax25_dev_list;
ax25_dev_list = ax25_dev;
spin_unlock_bh(&ax25_dev_lock);
ax25_register_dev_sysctl(ax25_dev);
}
void ax25_dev_device_down(struct net_device *dev)
{
ax25_dev *s, *ax25_dev;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
return;
ax25_unregister_dev_sysctl(ax25_dev);
spin_lock_bh(&ax25_dev_lock);
#ifdef CONFIG_AX25_DAMA_SLAVE
ax25_ds_del_timer(ax25_dev);
#endif
/*
* Remove any packet forwarding that points to this device.
*/
for (s = ax25_dev_list; s != NULL; s = s->next)
if (s->forward == dev)
s->forward = NULL;
if ((s = ax25_dev_list) == ax25_dev) {
ax25_dev_list = s->next;
spin_unlock_bh(&ax25_dev_lock);
dev_put(dev);
kfree(ax25_dev);
return;
}
while (s != NULL && s->next != NULL) {
if (s->next == ax25_dev) {
s->next = ax25_dev->next;
spin_unlock_bh(&ax25_dev_lock);
dev_put(dev);
kfree(ax25_dev);
return;
}
s = s->next;
}
spin_unlock_bh(&ax25_dev_lock);
dev->ax25_ptr = NULL;
}
int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
{
ax25_dev *ax25_dev, *fwd_dev;
if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
return -EINVAL;
switch (cmd) {
case SIOCAX25ADDFWD:
if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
return -EINVAL;
if (ax25_dev->forward != NULL)
return -EINVAL;
ax25_dev->forward = fwd_dev->dev;
break;
case SIOCAX25DELFWD:
if (ax25_dev->forward == NULL)
return -EINVAL;
ax25_dev->forward = NULL;
break;
default:
return -EINVAL;
}
return 0;
}
struct net_device *ax25_fwd_dev(struct net_device *dev)
{
ax25_dev *ax25_dev;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
return dev;
if (ax25_dev->forward == NULL)
return dev;
return ax25_dev->forward;
}
/*
* Free all memory associated with device structures.
*/
void __exit ax25_dev_free(void)
{
ax25_dev *s, *ax25_dev;
spin_lock_bh(&ax25_dev_lock);
ax25_dev = ax25_dev_list;
while (ax25_dev != NULL) {
s = ax25_dev;
dev_put(ax25_dev->dev);
ax25_dev = ax25_dev->next;
kfree(s);
}
ax25_dev_list = NULL;
spin_unlock_bh(&ax25_dev_lock);
}
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