ia64/linux-2.6.18-xen.hg

view arch/um/sys-i386/bugs.c @ 647:a5bb490065f6

Fix the build after public header sync.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Aug 13 14:01:49 2008 +0100 (2008-08-13)
parents 831230e53067
children
line source
1 /*
2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
6 #include <unistd.h>
7 #include <errno.h>
8 #include <string.h>
9 #include <sys/signal.h>
10 #include <asm/ldt.h>
11 #include "kern_util.h"
12 #include "user.h"
13 #include "sysdep/ptrace.h"
14 #include "task.h"
15 #include "os.h"
17 #define MAXTOKEN 64
19 /* Set during early boot */
20 int host_has_cmov = 1;
21 int host_has_xmm = 0;
23 static char token(int fd, char *buf, int len, char stop)
24 {
25 int n;
26 char *ptr, *end, c;
28 ptr = buf;
29 end = &buf[len];
30 do {
31 n = os_read_file(fd, ptr, sizeof(*ptr));
32 c = *ptr++;
33 if(n != sizeof(*ptr)){
34 if(n == 0) return(0);
35 printk("Reading /proc/cpuinfo failed, err = %d\n", -n);
36 if(n < 0)
37 return(n);
38 else
39 return(-EIO);
40 }
41 } while((c != '\n') && (c != stop) && (ptr < end));
43 if(ptr == end){
44 printk("Failed to find '%c' in /proc/cpuinfo\n", stop);
45 return(-1);
46 }
47 *(ptr - 1) = '\0';
48 return(c);
49 }
51 static int find_cpuinfo_line(int fd, char *key, char *scratch, int len)
52 {
53 int n;
54 char c;
56 scratch[len - 1] = '\0';
57 while(1){
58 c = token(fd, scratch, len - 1, ':');
59 if(c <= 0)
60 return(0);
61 else if(c != ':'){
62 printk("Failed to find ':' in /proc/cpuinfo\n");
63 return(0);
64 }
66 if(!strncmp(scratch, key, strlen(key)))
67 return(1);
69 do {
70 n = os_read_file(fd, &c, sizeof(c));
71 if(n != sizeof(c)){
72 printk("Failed to find newline in "
73 "/proc/cpuinfo, err = %d\n", -n);
74 return(0);
75 }
76 } while(c != '\n');
77 }
78 return(0);
79 }
81 int cpu_feature(char *what, char *buf, int len)
82 {
83 int fd, ret = 0;
85 fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0);
86 if(fd < 0){
87 printk("Couldn't open /proc/cpuinfo, err = %d\n", -fd);
88 return(0);
89 }
91 if(!find_cpuinfo_line(fd, what, buf, len)){
92 printk("Couldn't find '%s' line in /proc/cpuinfo\n", what);
93 goto out_close;
94 }
96 token(fd, buf, len, '\n');
97 ret = 1;
99 out_close:
100 os_close_file(fd);
101 return(ret);
102 }
104 static int check_cpu_flag(char *feature, int *have_it)
105 {
106 char buf[MAXTOKEN], c;
107 int fd, len = sizeof(buf)/sizeof(buf[0]);
109 printk("Checking for host processor %s support...", feature);
110 fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0);
111 if(fd < 0){
112 printk("Couldn't open /proc/cpuinfo, err = %d\n", -fd);
113 return(0);
114 }
116 *have_it = 0;
117 if(!find_cpuinfo_line(fd, "flags", buf, sizeof(buf) / sizeof(buf[0])))
118 goto out;
120 c = token(fd, buf, len - 1, ' ');
121 if(c < 0) goto out;
122 else if(c != ' '){
123 printk("Failed to find ' ' in /proc/cpuinfo\n");
124 goto out;
125 }
127 while(1){
128 c = token(fd, buf, len - 1, ' ');
129 if(c < 0) goto out;
130 else if(c == '\n') break;
132 if(!strcmp(buf, feature)){
133 *have_it = 1;
134 goto out;
135 }
136 }
137 out:
138 if(*have_it == 0) printk("No\n");
139 else if(*have_it == 1) printk("Yes\n");
140 os_close_file(fd);
141 return(1);
142 }
144 #if 0 /* This doesn't work in tt mode, plus it's causing compilation problems
145 * for some people.
146 */
147 static void disable_lcall(void)
148 {
149 struct modify_ldt_ldt_s ldt;
150 int err;
152 bzero(&ldt, sizeof(ldt));
153 ldt.entry_number = 7;
154 ldt.base_addr = 0;
155 ldt.limit = 0;
156 err = modify_ldt(1, &ldt, sizeof(ldt));
157 if(err)
158 printk("Failed to disable lcall7 - errno = %d\n", errno);
159 }
160 #endif
162 void arch_init_thread(void)
163 {
164 #if 0
165 disable_lcall();
166 #endif
167 }
169 void arch_check_bugs(void)
170 {
171 int have_it;
173 if(os_access("/proc/cpuinfo", OS_ACC_R_OK) < 0){
174 printk("/proc/cpuinfo not available - skipping CPU capability "
175 "checks\n");
176 return;
177 }
178 if(check_cpu_flag("cmov", &have_it))
179 host_has_cmov = have_it;
180 if(check_cpu_flag("xmm", &have_it))
181 host_has_xmm = have_it;
182 }
184 int arch_handle_signal(int sig, union uml_pt_regs *regs)
185 {
186 unsigned char tmp[2];
188 /* This is testing for a cmov (0x0f 0x4x) instruction causing a
189 * SIGILL in init.
190 */
191 if((sig != SIGILL) || (TASK_PID(get_current()) != 1)) return(0);
193 if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2))
194 panic("SIGILL in init, could not read instructions!\n");
195 if((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
196 return(0);
198 if(host_has_cmov == 0)
199 panic("SIGILL caused by cmov, which this processor doesn't "
200 "implement, boot a filesystem compiled for older "
201 "processors");
202 else if(host_has_cmov == 1)
203 panic("SIGILL caused by cmov, which this processor claims to "
204 "implement");
205 else if(host_has_cmov == -1)
206 panic("SIGILL caused by cmov, couldn't tell if this processor "
207 "implements it, boot a filesystem compiled for older "
208 "processors");
209 else panic("Bad value for host_has_cmov (%d)", host_has_cmov);
210 return(0);
211 }
213 /*
214 * Overrides for Emacs so that we follow Linus's tabbing style.
215 * Emacs will notice this stuff at the end of the file and automatically
216 * adjust the settings for this buffer only. This must remain at the end
217 * of the file.
218 * ---------------------------------------------------------------------------
219 * Local variables:
220 * c-file-style: "linux"
221 * End:
222 */