1 /*
2 * Copyright (C) 2012-2013 ProFUSION embedded systems
3 * Copyright (C) 2012-2013 Lucas De Marchi <lucas.de.marchi@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #ifndef HAVE_FINIT_MODULE
20 #define HAVE_FINIT_MODULE 1
21 #endif
22
23 #include <assert.h>
24 #include <dirent.h>
25 #include <dlfcn.h>
26 #include <elf.h>
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <limits.h>
30 #include <stdarg.h>
31 #include <stddef.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
36 #include <sys/mman.h>
37 #include <sys/stat.h>
38 #include <sys/syscall.h>
39 #include <sys/types.h>
40 #include <sys/utsname.h>
41
42 #include <shared/util.h>
43
44 /* kmod_elf_get_section() is not exported, we need the private header */
45 #include <libkmod/libkmod-internal.h>
46
47 /* FIXME: hack, change name so we don't clash */
48 #undef ERR
49 #include "testsuite.h"
50 #include "stripped-module.h"
51
52 struct mod {
53 struct mod *next;
54 int ret;
55 int errcode;
56 char name[];
57 };
58
59 static struct mod *modules;
60 static bool need_init = true;
61 static struct kmod_ctx *ctx;
62
parse_retcodes(struct mod * _modules,const char * s)63 static void parse_retcodes(struct mod *_modules, const char *s)
64 {
65 const char *p;
66
67 if (s == NULL)
68 return;
69
70 for (p = s;;) {
71 struct mod *mod;
72 const char *modname;
73 char *end;
74 size_t modnamelen;
75 int ret, errcode;
76 long l;
77
78 modname = p;
79 if (modname == NULL || modname[0] == '\0')
80 break;
81
82 modnamelen = strcspn(s, ":");
83 if (modname[modnamelen] != ':')
84 break;
85
86 p = modname + modnamelen + 1;
87 if (p == NULL)
88 break;
89
90 l = strtol(p, &end, 0);
91 if (end == p || *end != ':')
92 break;
93 ret = (int) l;
94 p = end + 1;
95
96 l = strtol(p, &end, 0);
97 if (*end == ':')
98 p = end + 1;
99 else if (*end != '\0')
100 break;
101
102 errcode = (int) l;
103
104 mod = malloc(sizeof(*mod) + modnamelen + 1);
105 if (mod == NULL)
106 break;
107
108 memcpy(mod->name, modname, modnamelen);
109 mod->name[modnamelen] = '\0';
110 mod->ret = ret;
111 mod->errcode = errcode;
112 mod->next = _modules;
113 _modules = mod;
114 }
115 }
116
write_one_line_file(const char * fn,const char * line,int len)117 static int write_one_line_file(const char *fn, const char *line, int len)
118 {
119 FILE *f;
120 int r;
121
122 assert(fn);
123 assert(line);
124
125 f = fopen(fn, "we");
126 if (!f)
127 return -errno;
128
129 errno = 0;
130 if (fputs(line, f) < 0) {
131 r = -errno;
132 goto finish;
133 }
134
135 fflush(f);
136
137 if (ferror(f)) {
138 if (errno != 0)
139 r = -errno;
140 else
141 r = -EIO;
142 } else
143 r = 0;
144
145 finish:
146 fclose(f);
147 return r;
148 }
149
create_sysfs_files(const char * modname)150 static int create_sysfs_files(const char *modname)
151 {
152 char buf[PATH_MAX];
153 const char *sysfsmod = "/sys/module/";
154 int len = strlen(sysfsmod);
155
156 memcpy(buf, sysfsmod, len);
157 strcpy(buf + len, modname);
158 len += strlen(modname);
159
160 assert(mkdir_p(buf, len, 0755) >= 0);
161
162 strcpy(buf + len, "/initstate");
163 return write_one_line_file(buf, "live\n", strlen("live\n"));
164 }
165
find_module(struct mod * _modules,const char * modname)166 static struct mod *find_module(struct mod *_modules, const char *modname)
167 {
168 struct mod *mod;
169
170 for (mod = _modules; mod != NULL; mod = mod->next) {
171 if (streq(mod->name, modname))
172 return mod;
173 }
174
175 return NULL;
176 }
177
init_retcodes(void)178 static void init_retcodes(void)
179 {
180 const char *s;
181
182 if (!need_init)
183 return;
184
185 need_init = false;
186 s = getenv(S_TC_INIT_MODULE_RETCODES);
187 if (s == NULL) {
188 fprintf(stderr, "TRAP init_module(): missing export %s?\n",
189 S_TC_INIT_MODULE_RETCODES);
190 }
191
192 ctx = kmod_new(NULL, NULL);
193
194 parse_retcodes(modules, s);
195 }
196
module_is_inkernel(const char * modname)197 static inline bool module_is_inkernel(const char *modname)
198 {
199 struct kmod_module *mod;
200 int state;
201 bool ret;
202
203 if (kmod_module_new_from_name(ctx, modname, &mod) < 0)
204 return false;
205
206 state = kmod_module_get_initstate(mod);
207
208 if (state == KMOD_MODULE_LIVE ||
209 state == KMOD_MODULE_BUILTIN)
210 ret = true;
211 else
212 ret = false;
213
214 kmod_module_unref(mod);
215
216 return ret;
217 }
218
elf_identify(void * mem)219 static uint8_t elf_identify(void *mem)
220 {
221 uint8_t *p = mem;
222 return p[EI_CLASS];
223 }
224
225 TS_EXPORT long init_module(void *mem, unsigned long len, const char *args);
226
227 /*
228 * Default behavior is to try to mimic init_module behavior inside the kernel.
229 * If it is a simple test that you know the error code, set the return code
230 * in TESTSUITE_INIT_MODULE_RETCODES env var instead.
231 *
232 * The exception is when the module name is not find in the memory passed.
233 * This is because we want to be able to pass dummy modules (and not real
234 * ones) and it still work.
235 */
init_module(void * mem,unsigned long len,const char * args)236 long init_module(void *mem, unsigned long len, const char *args)
237 {
238 const char *modname;
239 struct kmod_elf *elf;
240 struct mod *mod;
241 const void *buf;
242 uint64_t bufsize;
243 int err;
244 uint8_t class;
245 off_t offset;
246
247 init_retcodes();
248
249 elf = kmod_elf_new(mem, len);
250 if (elf == NULL)
251 return 0;
252
253 err = kmod_elf_get_section(elf, ".gnu.linkonce.this_module", &buf,
254 &bufsize);
255 kmod_elf_unref(elf);
256
257 /* We couldn't parse the ELF file. Just exit as if it was successful */
258 if (err < 0)
259 return 0;
260
261 /* We need to open both 32 and 64 bits module - hack! */
262 class = elf_identify(mem);
263 if (class == ELFCLASS64)
264 offset = MODULE_NAME_OFFSET_64;
265 else
266 offset = MODULE_NAME_OFFSET_32;
267
268 modname = (char *)buf + offset;
269 mod = find_module(modules, modname);
270 if (mod != NULL) {
271 errno = mod->errcode;
272 err = mod->ret;
273 } else if (module_is_inkernel(modname)) {
274 err = -1;
275 errno = EEXIST;
276 } else
277 err = 0;
278
279 if (err == 0)
280 create_sysfs_files(modname);
281
282 return err;
283 }
284
check_kernel_version(int major,int minor)285 static int check_kernel_version(int major, int minor)
286 {
287 struct utsname u;
288 const char *p;
289 int maj = 0, min = 0;
290
291 if (uname(&u) < 0)
292 return false;
293 for (p = u.release; *p >= '0' && *p <= '9'; p++)
294 maj = maj * 10 + *p - '0';
295 if (*p == '.')
296 for (p++; *p >= '0' && *p <= '9'; p++)
297 min = min * 10 + *p - '0';
298 if (maj > major || (maj == major && min >= minor))
299 return true;
300 return false;
301 }
302
303
304 TS_EXPORT int finit_module(const int fd, const char *args, const int flags);
305
finit_module(const int fd,const char * args,const int flags)306 int finit_module(const int fd, const char *args, const int flags)
307 {
308 int err;
309 void *mem;
310 unsigned long len;
311 struct stat st;
312
313 if (!check_kernel_version(3, 8)) {
314 errno = ENOSYS;
315 return -1;
316 }
317 if (fstat(fd, &st) < 0)
318 return -1;
319
320 len = st.st_size;
321 mem = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
322 if (mem == MAP_FAILED)
323 return -1;
324
325 err = init_module(mem, len, args);
326 munmap(mem, len);
327
328 return err;
329 }
330
syscall(long int __sysno,...)331 TS_EXPORT long int syscall(long int __sysno, ...)
332 {
333 va_list ap;
334 long ret;
335
336 if (__sysno == -1) {
337 errno = ENOSYS;
338 return -1;
339 }
340
341 if (__sysno == __NR_finit_module) {
342 const char *args;
343 int flags;
344 int fd;
345
346 va_start(ap, __sysno);
347
348 fd = va_arg(ap, int);
349 args = va_arg(ap, const char *);
350 flags = va_arg(ap, int);
351
352 ret = finit_module(fd, args, flags);
353
354 va_end(ap);
355 return ret;
356 }
357
358 if (__sysno == __NR_gettid) {
359 static void *nextlib = NULL;
360 static long (*nextlib_syscall)(long number, ...);
361
362 if (nextlib_syscall == NULL) {
363 #ifdef RTLD_NEXT
364 nextlib = RTLD_NEXT;
365 #else
366 nextlib = dlopen("libc.so.6", RTLD_LAZY);
367 #endif
368 nextlib_syscall = dlsym(nextlib, "syscall");
369 if (nextlib_syscall == NULL) {
370 fprintf(stderr, "FIXME FIXME FIXME: could not load syscall symbol: %s\n",
371 dlerror());
372 abort();
373 }
374 }
375
376 return nextlib_syscall(__NR_gettid);
377 }
378
379 /*
380 * FIXME: no way to call the libc function due since this is a
381 * variadic argument function and we don't have a vsyscall() variant
382 * this may fail if a library or process is trying to call syscall()
383 * directly, for example to implement gettid().
384 */
385 fprintf(stderr, "FIXME FIXME FIXME: could not wrap call to syscall(%ld), this should not happen\n",
386 __sysno);
387
388 abort();
389 }
390
391 /* the test is going away anyway, but lets keep valgrind happy */
392 void free_resources(void) __attribute__((destructor));
free_resources(void)393 void free_resources(void)
394 {
395 while (modules) {
396 struct mod *mod = modules->next;
397 free(modules);
398 modules = mod;
399 }
400
401 if (ctx)
402 kmod_unref(ctx);
403 }
404