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_addr.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/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.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>
/*
* The default broadcast address of an interface is QST-0; the default address
* is LINUX-1. The null address is defined as a callsign of all spaces with
* an SSID of zero.
*/
const ax25_address ax25_bcast =
{{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
const ax25_address ax25_defaddr =
{{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
const ax25_address null_ax25_address =
{{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
EXPORT_SYMBOL_GPL(ax25_bcast);
EXPORT_SYMBOL_GPL(ax25_defaddr);
EXPORT_SYMBOL(null_ax25_address);
/*
* ax25 -> ascii conversion
*/
char *ax2asc(char *buf, const ax25_address *a)
{
char c, *s;
int n;
for (n = 0, s = buf; n < 6; n++) {
c = (a->ax25_call[n] >> 1) & 0x7F;
if (c != ' ') *s++ = c;
}
*s++ = '-';
if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
*s++ = '1';
n -= 10;
}
*s++ = n + '0';
*s++ = '\0';
if (*buf == '\0' || *buf == '-')
return "*";
return buf;
}
EXPORT_SYMBOL(ax2asc);
/*
* ascii -> ax25 conversion
*/
void asc2ax(ax25_address *addr, const char *callsign)
{
const char *s;
int n;
for (s = callsign, n = 0; n < 6; n++) {
if (*s != '\0' && *s != '-')
addr->ax25_call[n] = *s++;
else
addr->ax25_call[n] = ' ';
addr->ax25_call[n] <<= 1;
addr->ax25_call[n] &= 0xFE;
}
if (*s++ == '\0') {
addr->ax25_call[6] = 0x00;
return;
}
addr->ax25_call[6] = *s++ - '0';
if (*s != '\0') {
addr->ax25_call[6] *= 10;
addr->ax25_call[6] += *s++ - '0';
}
addr->ax25_call[6] <<= 1;
addr->ax25_call[6] &= 0x1E;
}
EXPORT_SYMBOL(asc2ax);
/*
* Compare two ax.25 addresses
*/
int ax25cmp(const ax25_address *a, const ax25_address *b)
{
int ct = 0;
while (ct < 6) {
if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE)) /* Clean off repeater bits */
return 1;
ct++;
}
if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E)) /* SSID without control bit */
return 0;
return 2; /* Partial match */
}
EXPORT_SYMBOL(ax25cmp);
/*
* Compare two AX.25 digipeater paths.
*/
int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
{
int i;
if (digi1->ndigi != digi2->ndigi)
return 1;
if (digi1->lastrepeat != digi2->lastrepeat)
return 1;
for (i = 0; i < digi1->ndigi; i++)
if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
return 1;
return 0;
}
/*
* Given an AX.25 address pull of to, from, digi list, command/response and the start of data
*
*/
const unsigned char *ax25_addr_parse(const unsigned char *buf, int len,
ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags,
int *dama)
{
int d = 0;
if (len < 14) return NULL;
if (flags != NULL) {
*flags = 0;
if (buf[6] & AX25_CBIT)
*flags = AX25_COMMAND;
if (buf[13] & AX25_CBIT)
*flags = AX25_RESPONSE;
}
if (dama != NULL)
*dama = ~buf[13] & AX25_DAMA_FLAG;
/* Copy to, from */
if (dest != NULL)
memcpy(dest, buf + 0, AX25_ADDR_LEN);
if (src != NULL)
memcpy(src, buf + 7, AX25_ADDR_LEN);
buf += 2 * AX25_ADDR_LEN;
len -= 2 * AX25_ADDR_LEN;
digi->lastrepeat = -1;
digi->ndigi = 0;
while (!(buf[-1] & AX25_EBIT)) {
if (d >= AX25_MAX_DIGIS)
return NULL;
if (len < AX25_ADDR_LEN)
return NULL;
memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
digi->ndigi = d + 1;
if (buf[6] & AX25_HBIT) {
digi->repeated[d] = 1;
digi->lastrepeat = d;
} else {
digi->repeated[d] = 0;
}
buf += AX25_ADDR_LEN;
len -= AX25_ADDR_LEN;
d++;
}
return buf;
}
/*
* Assemble an AX.25 header from the bits
*/
int ax25_addr_build(unsigned char *buf, const ax25_address *src,
const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
{
int len = 0;
int ct = 0;
memcpy(buf, dest, AX25_ADDR_LEN);
buf[6] &= ~(AX25_EBIT | AX25_CBIT);
buf[6] |= AX25_SSSID_SPARE;
if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
buf += AX25_ADDR_LEN;
len += AX25_ADDR_LEN;
memcpy(buf, src, AX25_ADDR_LEN);
buf[6] &= ~(AX25_EBIT | AX25_CBIT);
buf[6] &= ~AX25_SSSID_SPARE;
if (modulus == AX25_MODULUS)
buf[6] |= AX25_SSSID_SPARE;
else
buf[6] |= AX25_ESSID_SPARE;
if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
/*
* Fast path the normal digiless path
*/
if (d == NULL || d->ndigi == 0) {
buf[6] |= AX25_EBIT;
return 2 * AX25_ADDR_LEN;
}
buf += AX25_ADDR_LEN;
len += AX25_ADDR_LEN;
while (ct < d->ndigi) {
memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
if (d->repeated[ct])
buf[6] |= AX25_HBIT;
else
buf[6] &= ~AX25_HBIT;
buf[6] &= ~AX25_EBIT;
buf[6] |= AX25_SSSID_SPARE;
buf += AX25_ADDR_LEN;
len += AX25_ADDR_LEN;
ct++;
}
buf[-1] |= AX25_EBIT;
return len;
}
int ax25_addr_size(const ax25_digi *dp)
{
if (dp == NULL)
return 2 * AX25_ADDR_LEN;
return AX25_ADDR_LEN * (2 + dp->ndigi);
}
/*
* Reverse Digipeat List. May not pass both parameters as same struct
*/
void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
{
int ct;
out->ndigi = in->ndigi;
out->lastrepeat = in->ndigi - in->lastrepeat - 2;
/* Invert the digipeaters */
for (ct = 0; ct < in->ndigi; ct++) {
out->calls[ct] = in->calls[in->ndigi - ct - 1];
if (ct <= out->lastrepeat) {
out->calls[ct].ax25_call[6] |= AX25_HBIT;
out->repeated[ct] = 1;
} else {
out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
out->repeated[ct] = 0;
}
}
}
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