diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /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.c | 222 |
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 */ | ||
20 | int host_has_cmov = 1; | ||
21 | int host_has_xmm = 0; | ||
22 | |||
23 | static 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 | |||
51 | static 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 | |||
81 | int 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 | |||
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]); | ||
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 | */ | ||
147 | static 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 | |||
162 | void arch_init_thread(void) | ||
163 | { | ||
164 | #if 0 | ||
165 | disable_lcall(); | ||
166 | #endif | ||
167 | } | ||
168 | |||
169 | void 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 | |||
184 | int 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 | */ | ||