Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
2eb5f31b | 2 | * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de) |
ba180fd4 | 3 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
4 | * Licensed under the GPL |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <stdio.h> |
8 | #include <stdlib.h> | |
ba180fd4 | 9 | #include <unistd.h> |
1da177e4 | 10 | #include <errno.h> |
ba180fd4 JD |
11 | #include <signal.h> |
12 | #include <string.h> | |
1da177e4 | 13 | #include <sys/resource.h> |
37185b33 AV |
14 | #include <as-layout.h> |
15 | #include <init.h> | |
16 | #include <kern_util.h> | |
17 | #include <os.h> | |
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 | ||
b743ac54 RW |
24 | long elf_aux_hwcap; |
25 | ||
1da177e4 LT |
26 | static void set_stklim(void) |
27 | { | |
28 | struct rlimit lim; | |
29 | ||
ba180fd4 | 30 | if (getrlimit(RLIMIT_STACK, &lim) < 0) { |
1da177e4 LT |
31 | perror("getrlimit"); |
32 | exit(1); | |
33 | } | |
ba180fd4 | 34 | if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) { |
1da177e4 | 35 | lim.rlim_cur = STACKSIZE; |
ba180fd4 | 36 | if (setrlimit(RLIMIT_STACK, &lim) < 0) { |
1da177e4 LT |
37 | perror("setrlimit"); |
38 | exit(1); | |
39 | } | |
40 | } | |
1da177e4 LT |
41 | } |
42 | ||
1da177e4 LT |
43 | static void last_ditch_exit(int sig) |
44 | { | |
1da177e4 LT |
45 | uml_cleanup(); |
46 | exit(1); | |
47 | } | |
48 | ||
4b84c69b JD |
49 | static void install_fatal_handler(int sig) |
50 | { | |
51 | struct sigaction action; | |
52 | ||
53 | /* All signals are enabled in this handler ... */ | |
54 | sigemptyset(&action.sa_mask); | |
55 | ||
ba180fd4 JD |
56 | /* |
57 | * ... including the signal being handled, plus we want the | |
4b84c69b JD |
58 | * handler reset to the default behavior, so that if an exit |
59 | * handler is hanging for some reason, the UML will just die | |
60 | * after this signal is sent a second time. | |
61 | */ | |
62 | action.sa_flags = SA_RESETHAND | SA_NODEFER; | |
63 | action.sa_restorer = NULL; | |
64 | action.sa_handler = last_ditch_exit; | |
ba180fd4 | 65 | if (sigaction(sig, &action, NULL) < 0) { |
0936d4f3 MH |
66 | os_warn("failed to install handler for signal %d " |
67 | "- errno = %d\n", sig, errno); | |
4b84c69b JD |
68 | exit(1); |
69 | } | |
70 | } | |
71 | ||
0ce451ac | 72 | #define UML_LIB_PATH ":" OS_LIB_PATH "/uml" |
cb98cdcd MD |
73 | |
74 | static void setup_env_path(void) | |
75 | { | |
76 | char *new_path = NULL; | |
77 | char *old_path = NULL; | |
78 | int path_len = 0; | |
79 | ||
80 | old_path = getenv("PATH"); | |
ba180fd4 JD |
81 | /* |
82 | * if no PATH variable is set or it has an empty value | |
cb98cdcd MD |
83 | * just use the default + /usr/lib/uml |
84 | */ | |
85 | if (!old_path || (path_len = strlen(old_path)) == 0) { | |
c9a3072d WC |
86 | if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH)) |
87 | perror("couldn't putenv"); | |
cb98cdcd MD |
88 | return; |
89 | } | |
90 | ||
91 | /* append /usr/lib/uml to the existing path */ | |
92 | path_len += strlen("PATH=" UML_LIB_PATH) + 1; | |
93 | new_path = malloc(path_len); | |
94 | if (!new_path) { | |
c9a3072d | 95 | perror("couldn't malloc to set a new PATH"); |
cb98cdcd MD |
96 | return; |
97 | } | |
98 | snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); | |
c9a3072d WC |
99 | if (putenv(new_path)) { |
100 | perror("couldn't putenv to set a new PATH"); | |
101 | free(new_path); | |
102 | } | |
cb98cdcd MD |
103 | } |
104 | ||
1da177e4 LT |
105 | extern void scan_elf_aux( char **envp); |
106 | ||
36e45463 | 107 | int __init main(int argc, char **argv, char **envp) |
1da177e4 LT |
108 | { |
109 | char **new_argv; | |
92515da7 | 110 | int ret, i, err; |
1da177e4 | 111 | |
1da177e4 LT |
112 | set_stklim(); |
113 | ||
cb98cdcd MD |
114 | setup_env_path(); |
115 | ||
25012721 RW |
116 | setsid(); |
117 | ||
1da177e4 | 118 | new_argv = malloc((argc + 1) * sizeof(char *)); |
ba180fd4 | 119 | if (new_argv == NULL) { |
1da177e4 LT |
120 | perror("Mallocing argv"); |
121 | exit(1); | |
122 | } | |
ba180fd4 | 123 | for (i = 0; i < argc; i++) { |
1da177e4 | 124 | new_argv[i] = strdup(argv[i]); |
ba180fd4 | 125 | if (new_argv[i] == NULL) { |
1da177e4 LT |
126 | perror("Mallocing an arg"); |
127 | exit(1); | |
128 | } | |
129 | } | |
130 | new_argv[argc] = NULL; | |
131 | ||
ba180fd4 JD |
132 | /* |
133 | * Allow these signals to bring down a UML if all other | |
4b84c69b JD |
134 | * methods of control fail. |
135 | */ | |
136 | install_fatal_handler(SIGINT); | |
137 | install_fatal_handler(SIGTERM); | |
1da177e4 | 138 | |
b743ac54 | 139 | #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA |
ba180fd4 | 140 | scan_elf_aux(envp); |
b743ac54 | 141 | #endif |
1da177e4 | 142 | |
9fcb663b | 143 | change_sig(SIGPIPE, 0); |
1da177e4 LT |
144 | ret = linux_main(argc, argv); |
145 | ||
ba180fd4 JD |
146 | /* |
147 | * Disable SIGPROF - I have no idea why libc doesn't do this or turn | |
1da177e4 LT |
148 | * off the profiling time, but UML dies with a SIGPROF just before |
149 | * exiting when profiling is active. | |
150 | */ | |
151 | change_sig(SIGPROF, 0); | |
152 | ||
ba180fd4 JD |
153 | /* |
154 | * This signal stuff used to be in the reboot case. However, | |
2eb5f31b | 155 | * sometimes a timer signal can come in when we're halting (reproducably |
52c653b3 JD |
156 | * when writing out gcov information, presumably because that takes |
157 | * some time) and cause a segfault. | |
158 | */ | |
159 | ||
2eb5f31b AI |
160 | /* stop timers and set timer signal to be ignored */ |
161 | os_timer_disable(); | |
52c653b3 JD |
162 | |
163 | /* disable SIGIO for the fds and set SIGIO to be ignored */ | |
164 | err = deactivate_all_fds(); | |
ba180fd4 | 165 | if (err) |
0936d4f3 | 166 | os_warn("deactivate_all_fds failed, errno = %d\n", -err); |
52c653b3 | 167 | |
ba180fd4 JD |
168 | /* |
169 | * Let any pending signals fire now. This ensures | |
52c653b3 JD |
170 | * that they won't be delivered after the exec, when |
171 | * they are definitely not expected. | |
172 | */ | |
173 | unblock_signals(); | |
1da177e4 | 174 | |
d3878bb8 | 175 | os_info("\n"); |
92515da7 | 176 | /* Reboot */ |
ba180fd4 | 177 | if (ret) { |
1da177e4 LT |
178 | execvp(new_argv[0], new_argv); |
179 | perror("Failed to exec kernel"); | |
180 | ret = 1; | |
181 | } | |
a5ed1ffa | 182 | return uml_exitcode; |
1da177e4 LT |
183 | } |
184 | ||
1da177e4 LT |
185 | extern void *__real_malloc(int); |
186 | ||
187 | void *__wrap_malloc(int size) | |
188 | { | |
189 | void *ret; | |
190 | ||
ba180fd4 | 191 | if (!kmalloc_ok) |
a5ed1ffa | 192 | return __real_malloc(size); |
ba180fd4 | 193 | else if (size <= UM_KERN_PAGE_SIZE) |
c539ab73 | 194 | /* finding contiguous pages can be hard*/ |
43f5b308 | 195 | ret = uml_kmalloc(size, UM_GFP_KERNEL); |
e4c4bf99 | 196 | else ret = vmalloc(size); |
1da177e4 | 197 | |
ba180fd4 JD |
198 | /* |
199 | * glibc people insist that if malloc fails, errno should be | |
1da177e4 LT |
200 | * set by malloc as well. So we do. |
201 | */ | |
ba180fd4 | 202 | if (ret == NULL) |
1da177e4 LT |
203 | errno = ENOMEM; |
204 | ||
a5ed1ffa | 205 | return ret; |
1da177e4 LT |
206 | } |
207 | ||
208 | void *__wrap_calloc(int n, int size) | |
209 | { | |
210 | void *ptr = __wrap_malloc(n * size); | |
211 | ||
ba180fd4 | 212 | if (ptr == NULL) |
a5ed1ffa | 213 | return NULL; |
1da177e4 | 214 | memset(ptr, 0, n * size); |
a5ed1ffa | 215 | return ptr; |
1da177e4 LT |
216 | } |
217 | ||
218 | extern void __real_free(void *); | |
219 | ||
220 | extern unsigned long high_physmem; | |
221 | ||
222 | void __wrap_free(void *ptr) | |
223 | { | |
224 | unsigned long addr = (unsigned long) ptr; | |
225 | ||
ba180fd4 JD |
226 | /* |
227 | * We need to know how the allocation happened, so it can be correctly | |
1da177e4 LT |
228 | * freed. This is done by seeing what region of memory the pointer is |
229 | * in - | |
230 | * physical memory - kmalloc/kfree | |
231 | * kernel virtual memory - vmalloc/vfree | |
232 | * anywhere else - malloc/free | |
233 | * If kmalloc is not yet possible, then either high_physmem and/or | |
234 | * end_vm are still 0 (as at startup), in which case we call free, or | |
235 | * we have set them, but anyway addr has not been allocated from those | |
236 | * areas. So, in both cases __real_free is called. | |
237 | * | |
238 | * CAN_KMALLOC is checked because it would be bad to free a buffer | |
239 | * with kmalloc/vmalloc after they have been turned off during | |
240 | * shutdown. | |
241 | * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so | |
242 | * there is a possibility for memory leaks. | |
243 | */ | |
244 | ||
ba180fd4 JD |
245 | if ((addr >= uml_physmem) && (addr < high_physmem)) { |
246 | if (kmalloc_ok) | |
1da177e4 LT |
247 | kfree(ptr); |
248 | } | |
ba180fd4 JD |
249 | else if ((addr >= start_vm) && (addr < end_vm)) { |
250 | if (kmalloc_ok) | |
1da177e4 LT |
251 | vfree(ptr); |
252 | } | |
253 | else __real_free(ptr); | |
254 | } |