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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/sys-i386/bugs.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/um/sys-i386/bugs.c')
-rw-r--r--arch/um/sys-i386/bugs.c222
1 files changed, 222 insertions, 0 deletions
diff --git a/arch/um/sys-i386/bugs.c b/arch/um/sys-i386/bugs.c
new file mode 100644
index 000000000000..41b0ab2fe830
--- /dev/null
+++ b/arch/um/sys-i386/bugs.c
@@ -0,0 +1,222 @@
1/*
2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
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"
16
17#define MAXTOKEN 64
18
19/* Set during early boot */
20int host_has_cmov = 1;
21int host_has_xmm = 0;
22
23static char token(int fd, char *buf, int len, char stop)
24{
25 int n;
26 char *ptr, *end, c;
27
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));
42
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}
50
51static int find_cpuinfo_line(int fd, char *key, char *scratch, int len)
52{
53 int n;
54 char c;
55
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 }
65
66 if(!strncmp(scratch, key, strlen(key)))
67 return(1);
68
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}
80
81int cpu_feature(char *what, char *buf, int len)
82{
83 int fd, ret = 0;
84
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 }
90
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 }
95
96 token(fd, buf, len, '\n');
97 ret = 1;
98
99 out_close:
100 os_close_file(fd);
101 return(ret);
102}
103
104static int check_cpu_flag(char *feature, int *have_it)
105{
106 char buf[MAXTOKEN], c;
107 int fd, len = sizeof(buf)/sizeof(buf[0]);
108
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 }
115
116 *have_it = 0;
117 if(!find_cpuinfo_line(fd, "flags", buf, sizeof(buf) / sizeof(buf[0])))
118 goto out;
119
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 }
126
127 while(1){
128 c = token(fd, buf, len - 1, ' ');
129 if(c < 0) goto out;
130 else if(c == '\n') break;
131
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}
143
144#if 0 /* This doesn't work in tt mode, plus it's causing compilation problems
145 * for some people.
146 */
147static void disable_lcall(void)
148{
149 struct modify_ldt_ldt_s ldt;
150 int err;
151
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
161
162void arch_init_thread(void)
163{
164#if 0
165 disable_lcall();
166#endif
167}
168
169void arch_check_bugs(void)
170{
171 int have_it;
172
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}
183
184int arch_handle_signal(int sig, union uml_pt_regs *regs)
185{
186 unsigned char tmp[2];
187
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);
192
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);
197
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}
212
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 */