Revert "Fix very high interrupt rate for IRQ8 (rtc) unless pnpacpi=off"
[pv_ops_mirror.git] / arch / um / os-Linux / main.c
blob82c3778627b8e91e448e969022c7b06e1a2241ab
1 /*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <unistd.h>
9 #include <errno.h>
10 #include <signal.h>
11 #include <string.h>
12 #include <sys/resource.h>
13 #include "as-layout.h"
14 #include "init.h"
15 #include "kern_constants.h"
16 #include "kern_util.h"
17 #include "os.h"
18 #include "um_malloc.h"
20 #define PGD_BOUND (4 * 1024 * 1024)
21 #define STACKSIZE (8 * 1024 * 1024)
22 #define THREAD_NAME_LEN (256)
24 static void set_stklim(void)
26 struct rlimit lim;
28 if (getrlimit(RLIMIT_STACK, &lim) < 0) {
29 perror("getrlimit");
30 exit(1);
32 if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
33 lim.rlim_cur = STACKSIZE;
34 if (setrlimit(RLIMIT_STACK, &lim) < 0) {
35 perror("setrlimit");
36 exit(1);
41 static __init void do_uml_initcalls(void)
43 initcall_t *call;
45 call = &__uml_initcall_start;
46 while (call < &__uml_initcall_end) {
47 (*call)();
48 call++;
52 static void last_ditch_exit(int sig)
54 uml_cleanup();
55 exit(1);
58 static void install_fatal_handler(int sig)
60 struct sigaction action;
62 /* All signals are enabled in this handler ... */
63 sigemptyset(&action.sa_mask);
66 * ... including the signal being handled, plus we want the
67 * handler reset to the default behavior, so that if an exit
68 * handler is hanging for some reason, the UML will just die
69 * after this signal is sent a second time.
71 action.sa_flags = SA_RESETHAND | SA_NODEFER;
72 action.sa_restorer = NULL;
73 action.sa_handler = last_ditch_exit;
74 if (sigaction(sig, &action, NULL) < 0) {
75 printf("failed to install handler for signal %d - errno = %d\n",
76 errno);
77 exit(1);
81 #define UML_LIB_PATH ":/usr/lib/uml"
83 static void setup_env_path(void)
85 char *new_path = NULL;
86 char *old_path = NULL;
87 int path_len = 0;
89 old_path = getenv("PATH");
91 * if no PATH variable is set or it has an empty value
92 * just use the default + /usr/lib/uml
94 if (!old_path || (path_len = strlen(old_path)) == 0) {
95 putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH);
96 return;
99 /* append /usr/lib/uml to the existing path */
100 path_len += strlen("PATH=" UML_LIB_PATH) + 1;
101 new_path = malloc(path_len);
102 if (!new_path) {
103 perror("coudn't malloc to set a new PATH");
104 return;
106 snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
107 putenv(new_path);
110 extern int uml_exitcode;
112 extern void scan_elf_aux( char **envp);
114 int __init main(int argc, char **argv, char **envp)
116 char **new_argv;
117 int ret, i, err;
119 set_stklim();
121 setup_env_path();
123 new_argv = malloc((argc + 1) * sizeof(char *));
124 if (new_argv == NULL) {
125 perror("Mallocing argv");
126 exit(1);
128 for (i = 0; i < argc; i++) {
129 new_argv[i] = strdup(argv[i]);
130 if (new_argv[i] == NULL) {
131 perror("Mallocing an arg");
132 exit(1);
135 new_argv[argc] = NULL;
138 * Allow these signals to bring down a UML if all other
139 * methods of control fail.
141 install_fatal_handler(SIGINT);
142 install_fatal_handler(SIGTERM);
143 install_fatal_handler(SIGHUP);
145 scan_elf_aux(envp);
147 do_uml_initcalls();
148 ret = linux_main(argc, argv);
151 * Disable SIGPROF - I have no idea why libc doesn't do this or turn
152 * off the profiling time, but UML dies with a SIGPROF just before
153 * exiting when profiling is active.
155 change_sig(SIGPROF, 0);
158 * This signal stuff used to be in the reboot case. However,
159 * sometimes a SIGVTALRM can come in when we're halting (reproducably
160 * when writing out gcov information, presumably because that takes
161 * some time) and cause a segfault.
164 /* stop timers and set SIGVTALRM to be ignored */
165 disable_timer();
167 /* disable SIGIO for the fds and set SIGIO to be ignored */
168 err = deactivate_all_fds();
169 if (err)
170 printf("deactivate_all_fds failed, errno = %d\n", -err);
173 * Let any pending signals fire now. This ensures
174 * that they won't be delivered after the exec, when
175 * they are definitely not expected.
177 unblock_signals();
179 /* Reboot */
180 if (ret) {
181 printf("\n");
182 execvp(new_argv[0], new_argv);
183 perror("Failed to exec kernel");
184 ret = 1;
186 printf("\n");
187 return uml_exitcode;
190 extern void *__real_malloc(int);
192 void *__wrap_malloc(int size)
194 void *ret;
196 if (!kmalloc_ok)
197 return __real_malloc(size);
198 else if (size <= UM_KERN_PAGE_SIZE)
199 /* finding contiguous pages can be hard*/
200 ret = kmalloc(size, UM_GFP_KERNEL);
201 else ret = vmalloc(size);
204 * glibc people insist that if malloc fails, errno should be
205 * set by malloc as well. So we do.
207 if (ret == NULL)
208 errno = ENOMEM;
210 return ret;
213 void *__wrap_calloc(int n, int size)
215 void *ptr = __wrap_malloc(n * size);
217 if (ptr == NULL)
218 return NULL;
219 memset(ptr, 0, n * size);
220 return ptr;
223 extern void __real_free(void *);
225 extern unsigned long high_physmem;
227 void __wrap_free(void *ptr)
229 unsigned long addr = (unsigned long) ptr;
232 * We need to know how the allocation happened, so it can be correctly
233 * freed. This is done by seeing what region of memory the pointer is
234 * in -
235 * physical memory - kmalloc/kfree
236 * kernel virtual memory - vmalloc/vfree
237 * anywhere else - malloc/free
238 * If kmalloc is not yet possible, then either high_physmem and/or
239 * end_vm are still 0 (as at startup), in which case we call free, or
240 * we have set them, but anyway addr has not been allocated from those
241 * areas. So, in both cases __real_free is called.
243 * CAN_KMALLOC is checked because it would be bad to free a buffer
244 * with kmalloc/vmalloc after they have been turned off during
245 * shutdown.
246 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
247 * there is a possibility for memory leaks.
250 if ((addr >= uml_physmem) && (addr < high_physmem)) {
251 if (kmalloc_ok)
252 kfree(ptr);
254 else if ((addr >= start_vm) && (addr < end_vm)) {
255 if (kmalloc_ok)
256 vfree(ptr);
258 else __real_free(ptr);