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Commit | Line | Data |
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1da177e4 | 1 | /* |
ba180fd4 | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
1da177e4 LT |
6 | #include <stdio.h> |
7 | #include <stdlib.h> | |
ba180fd4 | 8 | #include <unistd.h> |
1da177e4 | 9 | #include <errno.h> |
ba180fd4 JD |
10 | #include <signal.h> |
11 | #include <string.h> | |
1da177e4 | 12 | #include <sys/resource.h> |
4ff83ce1 | 13 | #include "as-layout.h" |
1da177e4 | 14 | #include "init.h" |
ba180fd4 JD |
15 | #include "kern_constants.h" |
16 | #include "kern_util.h" | |
1da177e4 | 17 | #include "os.h" |
c13e5690 | 18 | #include "um_malloc.h" |
1da177e4 | 19 | |
1da177e4 LT |
20 | #define PGD_BOUND (4 * 1024 * 1024) |
21 | #define STACKSIZE (8 * 1024 * 1024) | |
22 | #define THREAD_NAME_LEN (256) | |
23 | ||
24 | static void set_stklim(void) | |
25 | { | |
26 | struct rlimit lim; | |
27 | ||
ba180fd4 | 28 | if (getrlimit(RLIMIT_STACK, &lim) < 0) { |
1da177e4 LT |
29 | perror("getrlimit"); |
30 | exit(1); | |
31 | } | |
ba180fd4 | 32 | if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) { |
1da177e4 | 33 | lim.rlim_cur = STACKSIZE; |
ba180fd4 | 34 | if (setrlimit(RLIMIT_STACK, &lim) < 0) { |
1da177e4 LT |
35 | perror("setrlimit"); |
36 | exit(1); | |
37 | } | |
38 | } | |
1da177e4 LT |
39 | } |
40 | ||
41 | static __init void do_uml_initcalls(void) | |
42 | { | |
43 | initcall_t *call; | |
44 | ||
45 | call = &__uml_initcall_start; | |
ba180fd4 | 46 | while (call < &__uml_initcall_end) { |
1da177e4 LT |
47 | (*call)(); |
48 | call++; | |
49 | } | |
50 | } | |
51 | ||
52 | static void last_ditch_exit(int sig) | |
53 | { | |
1da177e4 LT |
54 | uml_cleanup(); |
55 | exit(1); | |
56 | } | |
57 | ||
4b84c69b JD |
58 | static void install_fatal_handler(int sig) |
59 | { | |
60 | struct sigaction action; | |
61 | ||
62 | /* All signals are enabled in this handler ... */ | |
63 | sigemptyset(&action.sa_mask); | |
64 | ||
ba180fd4 JD |
65 | /* |
66 | * ... including the signal being handled, plus we want the | |
4b84c69b JD |
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. | |
70 | */ | |
71 | action.sa_flags = SA_RESETHAND | SA_NODEFER; | |
72 | action.sa_restorer = NULL; | |
73 | action.sa_handler = last_ditch_exit; | |
ba180fd4 | 74 | if (sigaction(sig, &action, NULL) < 0) { |
4b84c69b JD |
75 | printf("failed to install handler for signal %d - errno = %d\n", |
76 | errno); | |
77 | exit(1); | |
78 | } | |
79 | } | |
80 | ||
cb98cdcd MD |
81 | #define UML_LIB_PATH ":/usr/lib/uml" |
82 | ||
83 | static void setup_env_path(void) | |
84 | { | |
85 | char *new_path = NULL; | |
86 | char *old_path = NULL; | |
87 | int path_len = 0; | |
88 | ||
89 | old_path = getenv("PATH"); | |
ba180fd4 JD |
90 | /* |
91 | * if no PATH variable is set or it has an empty value | |
cb98cdcd MD |
92 | * just use the default + /usr/lib/uml |
93 | */ | |
94 | if (!old_path || (path_len = strlen(old_path)) == 0) { | |
95 | putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH); | |
96 | return; | |
97 | } | |
98 | ||
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; | |
105 | } | |
106 | snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); | |
107 | putenv(new_path); | |
108 | } | |
109 | ||
1da177e4 LT |
110 | extern int uml_exitcode; |
111 | ||
112 | extern void scan_elf_aux( char **envp); | |
113 | ||
36e45463 | 114 | int __init main(int argc, char **argv, char **envp) |
1da177e4 LT |
115 | { |
116 | char **new_argv; | |
92515da7 | 117 | int ret, i, err; |
1da177e4 | 118 | |
1da177e4 LT |
119 | set_stklim(); |
120 | ||
cb98cdcd MD |
121 | setup_env_path(); |
122 | ||
1da177e4 | 123 | new_argv = malloc((argc + 1) * sizeof(char *)); |
ba180fd4 | 124 | if (new_argv == NULL) { |
1da177e4 LT |
125 | perror("Mallocing argv"); |
126 | exit(1); | |
127 | } | |
ba180fd4 | 128 | for (i = 0; i < argc; i++) { |
1da177e4 | 129 | new_argv[i] = strdup(argv[i]); |
ba180fd4 | 130 | if (new_argv[i] == NULL) { |
1da177e4 LT |
131 | perror("Mallocing an arg"); |
132 | exit(1); | |
133 | } | |
134 | } | |
135 | new_argv[argc] = NULL; | |
136 | ||
ba180fd4 JD |
137 | /* |
138 | * Allow these signals to bring down a UML if all other | |
4b84c69b JD |
139 | * methods of control fail. |
140 | */ | |
141 | install_fatal_handler(SIGINT); | |
142 | install_fatal_handler(SIGTERM); | |
143 | install_fatal_handler(SIGHUP); | |
1da177e4 | 144 | |
ba180fd4 | 145 | scan_elf_aux(envp); |
1da177e4 LT |
146 | |
147 | do_uml_initcalls(); | |
148 | ret = linux_main(argc, argv); | |
149 | ||
ba180fd4 JD |
150 | /* |
151 | * Disable SIGPROF - I have no idea why libc doesn't do this or turn | |
1da177e4 LT |
152 | * off the profiling time, but UML dies with a SIGPROF just before |
153 | * exiting when profiling is active. | |
154 | */ | |
155 | change_sig(SIGPROF, 0); | |
156 | ||
ba180fd4 JD |
157 | /* |
158 | * This signal stuff used to be in the reboot case. However, | |
52c653b3 JD |
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. | |
162 | */ | |
163 | ||
164 | /* stop timers and set SIG*ALRM to be ignored */ | |
165 | disable_timer(); | |
166 | ||
167 | /* disable SIGIO for the fds and set SIGIO to be ignored */ | |
168 | err = deactivate_all_fds(); | |
ba180fd4 | 169 | if (err) |
52c653b3 JD |
170 | printf("deactivate_all_fds failed, errno = %d\n", -err); |
171 | ||
ba180fd4 JD |
172 | /* |
173 | * Let any pending signals fire now. This ensures | |
52c653b3 JD |
174 | * that they won't be delivered after the exec, when |
175 | * they are definitely not expected. | |
176 | */ | |
177 | unblock_signals(); | |
1da177e4 | 178 | |
92515da7 | 179 | /* Reboot */ |
ba180fd4 | 180 | if (ret) { |
92515da7 | 181 | printf("\n"); |
1da177e4 LT |
182 | execvp(new_argv[0], new_argv); |
183 | perror("Failed to exec kernel"); | |
184 | ret = 1; | |
185 | } | |
186 | printf("\n"); | |
a5ed1ffa | 187 | return uml_exitcode; |
1da177e4 LT |
188 | } |
189 | ||
1da177e4 LT |
190 | extern void *__real_malloc(int); |
191 | ||
192 | void *__wrap_malloc(int size) | |
193 | { | |
194 | void *ret; | |
195 | ||
ba180fd4 | 196 | if (!kmalloc_ok) |
a5ed1ffa | 197 | return __real_malloc(size); |
ba180fd4 | 198 | else if (size <= UM_KERN_PAGE_SIZE) |
c539ab73 | 199 | /* finding contiguous pages can be hard*/ |
e4c4bf99 JD |
200 | ret = kmalloc(size, UM_GFP_KERNEL); |
201 | else ret = vmalloc(size); | |
1da177e4 | 202 | |
ba180fd4 JD |
203 | /* |
204 | * glibc people insist that if malloc fails, errno should be | |
1da177e4 LT |
205 | * set by malloc as well. So we do. |
206 | */ | |
ba180fd4 | 207 | if (ret == NULL) |
1da177e4 LT |
208 | errno = ENOMEM; |
209 | ||
a5ed1ffa | 210 | return ret; |
1da177e4 LT |
211 | } |
212 | ||
213 | void *__wrap_calloc(int n, int size) | |
214 | { | |
215 | void *ptr = __wrap_malloc(n * size); | |
216 | ||
ba180fd4 | 217 | if (ptr == NULL) |
a5ed1ffa | 218 | return NULL; |
1da177e4 | 219 | memset(ptr, 0, n * size); |
a5ed1ffa | 220 | return ptr; |
1da177e4 LT |
221 | } |
222 | ||
223 | extern void __real_free(void *); | |
224 | ||
225 | extern unsigned long high_physmem; | |
226 | ||
227 | void __wrap_free(void *ptr) | |
228 | { | |
229 | unsigned long addr = (unsigned long) ptr; | |
230 | ||
ba180fd4 JD |
231 | /* |
232 | * We need to know how the allocation happened, so it can be correctly | |
1da177e4 LT |
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. | |
242 | * | |
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. | |
248 | */ | |
249 | ||
ba180fd4 JD |
250 | if ((addr >= uml_physmem) && (addr < high_physmem)) { |
251 | if (kmalloc_ok) | |
1da177e4 LT |
252 | kfree(ptr); |
253 | } | |
ba180fd4 JD |
254 | else if ((addr >= start_vm) && (addr < end_vm)) { |
255 | if (kmalloc_ok) | |
1da177e4 LT |
256 | vfree(ptr); |
257 | } | |
258 | else __real_free(ptr); | |
259 | } |