1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/******************************************************************************
* fixup.c
*
* Binary-rewriting of certain IA32 instructions, on notification by Xen.
* Used to avoid repeated slow emulation of common instructions used by the
* user-space TLS (Thread-Local Storage) libraries.
*
* **** NOTE ****
* Issues with the binary rewriting have caused it to be removed. Instead
* we rely on Xen's emulator to boot the kernel, and then print a banner
* message recommending that the user disables /lib/tls.
*
* Copyright (c) 2004, K A Fraser
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/version.h>
#define DP(_f, _args...) printk(KERN_ALERT " " _f "\n" , ## _args )
fastcall void do_fixup_4gb_segment(struct pt_regs *regs, long error_code)
{
static unsigned long printed = 0;
char info[100];
int i;
if (test_and_set_bit(0, &printed))
return;
if (current->tgid == 1) /* Ignore statically linked init */
return;
HYPERVISOR_vm_assist(
VMASST_CMD_disable, VMASST_TYPE_4gb_segments_notify);
sprintf(info, "%s (pid=%d)", current->comm, current->tgid);
DP("");
DP("***************************************************************");
DP("***************************************************************");
DP("** WARNING: Currently emulating unsupported memory accesses **");
DP("** in /lib/tls glibc libraries. The emulation is **");
DP("** slow. To ensure full performance you should **");
DP("** install a 'xen-friendly' (nosegneg) version of **");
DP("** the library, or disable tls support by executing **");
DP("** the following as root: **");
DP("** mv /lib/tls /lib/tls.disabled **");
DP("** Offending process: %-38.38s **", info);
DP("***************************************************************");
DP("***************************************************************");
DP("");
for (i = 5; i > 0; i--) {
touch_softlockup_watchdog();
printk("Pausing... %d", i);
mdelay(1000);
printk("\b\b\b\b\b\b\b\b\b\b\b\b");
}
printk("Continuing...\n\n");
}
static int __init fixup_init(void)
{
HYPERVISOR_vm_assist(
VMASST_CMD_enable, VMASST_TYPE_4gb_segments_notify);
return 0;
}
__initcall(fixup_init);
|
