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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Jeff Dikeba180fd2007-10-16 01:27:00 -07002 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * Licensed under the GPL
4 */
5
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include <stdio.h>
7#include <stdlib.h>
Jeff Dikeba180fd2007-10-16 01:27:00 -07008#include <unistd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <errno.h>
Jeff Dikeba180fd2007-10-16 01:27:00 -070010#include <signal.h>
11#include <string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <sys/resource.h>
Al Viro37185b32012-10-08 03:27:32 +010013#include <as-layout.h>
14#include <init.h>
15#include <kern_util.h>
16#include <os.h>
17#include <um_malloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#define PGD_BOUND (4 * 1024 * 1024)
20#define STACKSIZE (8 * 1024 * 1024)
21#define THREAD_NAME_LEN (256)
22
Richard Weinbergerb743ac52011-07-25 17:12:52 -070023long elf_aux_hwcap;
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025static void set_stklim(void)
26{
27 struct rlimit lim;
28
Jeff Dikeba180fd2007-10-16 01:27:00 -070029 if (getrlimit(RLIMIT_STACK, &lim) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 perror("getrlimit");
31 exit(1);
32 }
Jeff Dikeba180fd2007-10-16 01:27:00 -070033 if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 lim.rlim_cur = STACKSIZE;
Jeff Dikeba180fd2007-10-16 01:27:00 -070035 if (setrlimit(RLIMIT_STACK, &lim) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 perror("setrlimit");
37 exit(1);
38 }
39 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070040}
41
42static __init void do_uml_initcalls(void)
43{
44 initcall_t *call;
45
46 call = &__uml_initcall_start;
Jeff Dikeba180fd2007-10-16 01:27:00 -070047 while (call < &__uml_initcall_end) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 (*call)();
49 call++;
50 }
51}
52
53static void last_ditch_exit(int sig)
54{
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 uml_cleanup();
56 exit(1);
57}
58
Jeff Dike4b84c692006-09-25 23:33:04 -070059static void install_fatal_handler(int sig)
60{
61 struct sigaction action;
62
63 /* All signals are enabled in this handler ... */
64 sigemptyset(&action.sa_mask);
65
Jeff Dikeba180fd2007-10-16 01:27:00 -070066 /*
67 * ... including the signal being handled, plus we want the
Jeff Dike4b84c692006-09-25 23:33:04 -070068 * handler reset to the default behavior, so that if an exit
69 * handler is hanging for some reason, the UML will just die
70 * after this signal is sent a second time.
71 */
72 action.sa_flags = SA_RESETHAND | SA_NODEFER;
73 action.sa_restorer = NULL;
74 action.sa_handler = last_ditch_exit;
Jeff Dikeba180fd2007-10-16 01:27:00 -070075 if (sigaction(sig, &action, NULL) < 0) {
Jeff Dike4b84c692006-09-25 23:33:04 -070076 printf("failed to install handler for signal %d - errno = %d\n",
WANG Congc9a30722008-02-04 22:30:35 -080077 sig, errno);
Jeff Dike4b84c692006-09-25 23:33:04 -070078 exit(1);
79 }
80}
81
Richard Weinberger0ce451a2011-05-24 17:13:00 -070082#define UML_LIB_PATH ":" OS_LIB_PATH "/uml"
Mattia Dongilicb98cdc2006-05-01 12:16:01 -070083
84static void setup_env_path(void)
85{
86 char *new_path = NULL;
87 char *old_path = NULL;
88 int path_len = 0;
89
90 old_path = getenv("PATH");
Jeff Dikeba180fd2007-10-16 01:27:00 -070091 /*
92 * if no PATH variable is set or it has an empty value
Mattia Dongilicb98cdc2006-05-01 12:16:01 -070093 * just use the default + /usr/lib/uml
94 */
95 if (!old_path || (path_len = strlen(old_path)) == 0) {
WANG Congc9a30722008-02-04 22:30:35 -080096 if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
97 perror("couldn't putenv");
Mattia Dongilicb98cdc2006-05-01 12:16:01 -070098 return;
99 }
100
101 /* append /usr/lib/uml to the existing path */
102 path_len += strlen("PATH=" UML_LIB_PATH) + 1;
103 new_path = malloc(path_len);
104 if (!new_path) {
WANG Congc9a30722008-02-04 22:30:35 -0800105 perror("couldn't malloc to set a new PATH");
Mattia Dongilicb98cdc2006-05-01 12:16:01 -0700106 return;
107 }
108 snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
WANG Congc9a30722008-02-04 22:30:35 -0800109 if (putenv(new_path)) {
110 perror("couldn't putenv to set a new PATH");
111 free(new_path);
112 }
Mattia Dongilicb98cdc2006-05-01 12:16:01 -0700113}
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115extern void scan_elf_aux( char **envp);
116
Jeff Dike36e45462007-05-06 14:51:11 -0700117int __init main(int argc, char **argv, char **envp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
119 char **new_argv;
Jeff Dike92515da2005-05-28 15:51:56 -0700120 int ret, i, err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 set_stklim();
123
Mattia Dongilicb98cdc2006-05-01 12:16:01 -0700124 setup_env_path();
125
Richard Weinberger25012722013-08-18 13:30:09 +0200126 setsid();
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 new_argv = malloc((argc + 1) * sizeof(char *));
Jeff Dikeba180fd2007-10-16 01:27:00 -0700129 if (new_argv == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 perror("Mallocing argv");
131 exit(1);
132 }
Jeff Dikeba180fd2007-10-16 01:27:00 -0700133 for (i = 0; i < argc; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 new_argv[i] = strdup(argv[i]);
Jeff Dikeba180fd2007-10-16 01:27:00 -0700135 if (new_argv[i] == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 perror("Mallocing an arg");
137 exit(1);
138 }
139 }
140 new_argv[argc] = NULL;
141
Jeff Dikeba180fd2007-10-16 01:27:00 -0700142 /*
143 * Allow these signals to bring down a UML if all other
Jeff Dike4b84c692006-09-25 23:33:04 -0700144 * methods of control fail.
145 */
146 install_fatal_handler(SIGINT);
147 install_fatal_handler(SIGTERM);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Richard Weinbergerb743ac52011-07-25 17:12:52 -0700149#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
Jeff Dikeba180fd2007-10-16 01:27:00 -0700150 scan_elf_aux(envp);
Richard Weinbergerb743ac52011-07-25 17:12:52 -0700151#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 do_uml_initcalls();
154 ret = linux_main(argc, argv);
155
Jeff Dikeba180fd2007-10-16 01:27:00 -0700156 /*
157 * Disable SIGPROF - I have no idea why libc doesn't do this or turn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 * off the profiling time, but UML dies with a SIGPROF just before
159 * exiting when profiling is active.
160 */
161 change_sig(SIGPROF, 0);
162
Jeff Dikeba180fd2007-10-16 01:27:00 -0700163 /*
164 * This signal stuff used to be in the reboot case. However,
Jeff Dike52c653b2005-11-07 00:58:50 -0800165 * sometimes a SIGVTALRM can come in when we're halting (reproducably
166 * when writing out gcov information, presumably because that takes
167 * some time) and cause a segfault.
168 */
Jeff Dike92515da2005-05-28 15:51:56 -0700169
Jeff Dike61b63c52007-10-16 01:27:27 -0700170 /* stop timers and set SIGVTALRM to be ignored */
Jeff Dike52c653b2005-11-07 00:58:50 -0800171 disable_timer();
Jeff Dike92515da2005-05-28 15:51:56 -0700172
Jeff Dike52c653b2005-11-07 00:58:50 -0800173 /* disable SIGIO for the fds and set SIGIO to be ignored */
174 err = deactivate_all_fds();
Jeff Dikeba180fd2007-10-16 01:27:00 -0700175 if (err)
Jeff Dike52c653b2005-11-07 00:58:50 -0800176 printf("deactivate_all_fds failed, errno = %d\n", -err);
Jeff Dike92515da2005-05-28 15:51:56 -0700177
Jeff Dikeba180fd2007-10-16 01:27:00 -0700178 /*
179 * Let any pending signals fire now. This ensures
Jeff Dike52c653b2005-11-07 00:58:50 -0800180 * that they won't be delivered after the exec, when
181 * they are definitely not expected.
182 */
183 unblock_signals();
Jeff Dike92515da2005-05-28 15:51:56 -0700184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 /* Reboot */
Jeff Dikeba180fd2007-10-16 01:27:00 -0700186 if (ret) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 printf("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 execvp(new_argv[0], new_argv);
189 perror("Failed to exec kernel");
190 ret = 1;
191 }
192 printf("\n");
Jeff Dikea5ed1ff2007-05-06 14:50:58 -0700193 return uml_exitcode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194}
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196extern void *__real_malloc(int);
197
198void *__wrap_malloc(int size)
199{
200 void *ret;
201
Jeff Dikeba180fd2007-10-16 01:27:00 -0700202 if (!kmalloc_ok)
Jeff Dikea5ed1ff2007-05-06 14:50:58 -0700203 return __real_malloc(size);
Jeff Dikeba180fd2007-10-16 01:27:00 -0700204 else if (size <= UM_KERN_PAGE_SIZE)
Jeff Dikec539ab72007-06-16 10:16:09 -0700205 /* finding contiguous pages can be hard*/
Jeff Dike43f5b302008-05-12 14:01:52 -0700206 ret = uml_kmalloc(size, UM_GFP_KERNEL);
Jeff Dikee4c4bf92007-07-15 23:38:56 -0700207 else ret = vmalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Jeff Dikeba180fd2007-10-16 01:27:00 -0700209 /*
210 * glibc people insist that if malloc fails, errno should be
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 * set by malloc as well. So we do.
212 */
Jeff Dikeba180fd2007-10-16 01:27:00 -0700213 if (ret == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 errno = ENOMEM;
215
Jeff Dikea5ed1ff2007-05-06 14:50:58 -0700216 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219void *__wrap_calloc(int n, int size)
220{
221 void *ptr = __wrap_malloc(n * size);
222
Jeff Dikeba180fd2007-10-16 01:27:00 -0700223 if (ptr == NULL)
Jeff Dikea5ed1ff2007-05-06 14:50:58 -0700224 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 memset(ptr, 0, n * size);
Jeff Dikea5ed1ff2007-05-06 14:50:58 -0700226 return ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
229extern void __real_free(void *);
230
231extern unsigned long high_physmem;
232
233void __wrap_free(void *ptr)
234{
235 unsigned long addr = (unsigned long) ptr;
236
Jeff Dikeba180fd2007-10-16 01:27:00 -0700237 /*
238 * We need to know how the allocation happened, so it can be correctly
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 * freed. This is done by seeing what region of memory the pointer is
240 * in -
241 * physical memory - kmalloc/kfree
242 * kernel virtual memory - vmalloc/vfree
243 * anywhere else - malloc/free
244 * If kmalloc is not yet possible, then either high_physmem and/or
245 * end_vm are still 0 (as at startup), in which case we call free, or
246 * we have set them, but anyway addr has not been allocated from those
247 * areas. So, in both cases __real_free is called.
248 *
249 * CAN_KMALLOC is checked because it would be bad to free a buffer
250 * with kmalloc/vmalloc after they have been turned off during
251 * shutdown.
252 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
253 * there is a possibility for memory leaks.
254 */
255
Jeff Dikeba180fd2007-10-16 01:27:00 -0700256 if ((addr >= uml_physmem) && (addr < high_physmem)) {
257 if (kmalloc_ok)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 kfree(ptr);
259 }
Jeff Dikeba180fd2007-10-16 01:27:00 -0700260 else if ((addr >= start_vm) && (addr < end_vm)) {
261 if (kmalloc_ok)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 vfree(ptr);
263 }
264 else __real_free(ptr);
265}