2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
9 #include "kern_constants.h"
16 /* Set during early boot */
17 int host_has_cmov = 1;
19 static char token(int fd, char *buf, int len, char stop)
27 n = os_read_file(fd, ptr, sizeof(*ptr));
29 if (n != sizeof(*ptr)) {
32 printk(UM_KERN_ERR "Reading /proc/cpuinfo failed, "
38 } while ((c != '\n') && (c != stop) && (ptr < end));
41 printk(UM_KERN_ERR "Failed to find '%c' in /proc/cpuinfo\n",
49 static int find_cpuinfo_line(int fd, char *key, char *scratch, int len)
54 scratch[len - 1] = '\0';
56 c = token(fd, scratch, len - 1, ':');
60 printk(UM_KERN_ERR "Failed to find ':' in "
65 if (!strncmp(scratch, key, strlen(key)))
69 n = os_read_file(fd, &c, sizeof(c));
71 printk(UM_KERN_ERR "Failed to find newline in "
72 "/proc/cpuinfo, err = %d\n", -n);
80 static int check_cpu_flag(char *feature, int *have_it)
82 char buf[MAXTOKEN], c;
83 int fd, len = ARRAY_SIZE(buf);
85 printk(UM_KERN_INFO "Checking for host processor %s support...",
87 fd = os_open_file("/proc/cpuinfo", of_read(OPENFLAGS()), 0);
89 printk(UM_KERN_ERR "Couldn't open /proc/cpuinfo, err = %d\n",
95 if (!find_cpuinfo_line(fd, "flags", buf, ARRAY_SIZE(buf)))
98 c = token(fd, buf, len - 1, ' ');
102 printk(UM_KERN_ERR "Failed to find ' ' in /proc/cpuinfo\n");
107 c = token(fd, buf, len - 1, ' ');
113 if (!strcmp(buf, feature)) {
121 else if (*have_it == 1)
128 * This doesn't work in tt mode, plus it's causing compilation problems
131 static void disable_lcall(void)
133 struct modify_ldt_ldt_s ldt;
136 bzero(&ldt, sizeof(ldt));
137 ldt.entry_number = 7;
140 err = modify_ldt(1, &ldt, sizeof(ldt));
142 printk(UM_KERN_ERR "Failed to disable lcall7 - errno = %d\n",
147 void arch_init_thread(void)
154 void arch_check_bugs(void)
158 if (os_access("/proc/cpuinfo", OS_ACC_R_OK) < 0) {
159 printk(UM_KERN_ERR "/proc/cpuinfo not available - skipping CPU "
160 "capability checks\n");
163 if (check_cpu_flag("cmov", &have_it))
164 host_has_cmov = have_it;
167 int arch_handle_signal(int sig, struct uml_pt_regs *regs)
169 unsigned char tmp[2];
172 * This is testing for a cmov (0x0f 0x4x) instruction causing a
175 if ((sig != SIGILL) || (TASK_PID(get_current()) != 1))
178 if (copy_from_user_proc(tmp, (void *) UPT_IP(regs), 2))
179 panic("SIGILL in init, could not read instructions!\n");
180 if ((tmp[0] != 0x0f) || ((tmp[1] & 0xf0) != 0x40))
183 if (host_has_cmov == 0)
184 panic("SIGILL caused by cmov, which this processor doesn't "
185 "implement, boot a filesystem compiled for older "
187 else if (host_has_cmov == 1)
188 panic("SIGILL caused by cmov, which this processor claims to "
190 else if (host_has_cmov == -1)
191 panic("SIGILL caused by cmov, couldn't tell if this processor "
192 "implements it, boot a filesystem compiled for older "
194 else panic("Bad value for host_has_cmov (%d)", host_has_cmov);