Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int Presumably the (nid < 0) case has never happened. We do know that it is happening on one system while creating a symlink for a memory section so it should also happen on the same system if unregister_mem_sect_under_nodes() were called to remove the same symlink. The test was actually added in response to a problem with an earlier version reported by Yasunori Goto where one or more of the leading pages of a memory section on the 2nd node of one of his systems was uninitialized because I believe they coincided with a memory hole. That earlier version did not ignore uninitialized pages and determined the nid by considering only the 1st page of each memory section. This caused the symlink to the 1st memory section on the 2nd node to be incorrectly created in /sys/devices/system/node/node0 instead of /sys/devices/system/node/node1. The problem was fixed by adding the test to skip over uninitialized pages. I suspect we have not seen any reports of the non-removal of a symlink due to the incorrect declaration of the nid variable in unregister_mem_sect_under_nodes() because - systems where a memory section could have an uninitialized range of leading pages are probably rare. - memory remove is probably not done very frequently on the systems that are capable of demonstrating the problem. - lingering symlink(s) that should have been removed may have simply gone unnoticed. [garyhade@us.ibm.com: wrote changelog] Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1abaf33
hvc_beat.c
/*
* Beat hypervisor console driver
*
* (C) Copyright 2006 TOSHIBA CORPORATION
*
* This code is based on drivers/char/hvc_rtas.c:
* (C) Copyright IBM Corporation 2001-2005
* (C) Copyright Red Hat, Inc. 2005
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/console.h>
#include <asm/prom.h>
#include <asm/hvconsole.h>
#include <asm/firmware.h>
#include "hvc_console.h"
extern int64_t beat_get_term_char(uint64_t, uint64_t *, uint64_t *, uint64_t *);
extern int64_t beat_put_term_char(uint64_t, uint64_t, uint64_t, uint64_t);
struct hvc_struct *hvc_beat_dev = NULL;
/* bug: only one queue is available regardless of vtermno */
static int hvc_beat_get_chars(uint32_t vtermno, char *buf, int cnt)
{
static unsigned char q[sizeof(unsigned long) * 2]
__attribute__((aligned(sizeof(unsigned long))));
static int qlen = 0;
u64 got;
again:
if (qlen) {
if (qlen > cnt) {
memcpy(buf, q, cnt);
qlen -= cnt;
memmove(q + cnt, q, qlen);
return cnt;
} else { /* qlen <= cnt */
int r;
memcpy(buf, q, qlen);
r = qlen;
qlen = 0;
return r;
}
}
if (beat_get_term_char(vtermno, &got,
((u64 *)q), ((u64 *)q) + 1) == 0) {
qlen = got;
goto again;
}
return 0;
}
static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
{
unsigned long kb[2];
int rest, nlen;
for (rest = cnt; rest > 0; rest -= nlen) {
nlen = (rest > 16) ? 16 : rest;
memcpy(kb, buf, nlen);
beat_put_term_char(vtermno, nlen, kb[0], kb[1]);
buf += nlen;
}
return cnt;
}
static struct hv_ops hvc_beat_get_put_ops = {
.get_chars = hvc_beat_get_chars,
.put_chars = hvc_beat_put_chars,
};
static int hvc_beat_useit = 1;
static int hvc_beat_config(char *p)
{
hvc_beat_useit = simple_strtoul(p, NULL, 0);
return 0;
}
static int __init hvc_beat_console_init(void)
{
if (hvc_beat_useit && machine_is_compatible("Beat")) {
hvc_instantiate(0, 0, &hvc_beat_get_put_ops);
}
return 0;
}
/* temp */
static int __init hvc_beat_init(void)
{
struct hvc_struct *hp;
if (!firmware_has_feature(FW_FEATURE_BEAT))
return -ENODEV;
hp = hvc_alloc(0, NO_IRQ, &hvc_beat_get_put_ops, 16);
if (IS_ERR(hp))
return PTR_ERR(hp);
hvc_beat_dev = hp;
return 0;
}
static void __exit hvc_beat_exit(void)
{
if (hvc_beat_dev)
hvc_remove(hvc_beat_dev);
}
module_init(hvc_beat_init);
module_exit(hvc_beat_exit);
__setup("hvc_beat=", hvc_beat_config);
console_initcall(hvc_beat_console_init);
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