2 * Copyright (c) 2011 Comtrol Corp.
3 * Copyright (c) 2011-2018 The strace developers.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 struct path_set global_path_set;
40 * Return true if specified path matches one that we're tracing.
43 pathmatch(const char *path, struct path_set *set)
47 for (i = 0; i < set->num_selected; ++i) {
48 if (strcmp(path, set->paths_selected[i]) == 0)
55 * Return true if specified path (in user-space) matches.
58 upathmatch(struct tcb *const tcp, const kernel_ulong_t upath,
61 char path[PATH_MAX + 1];
63 return umovestr(tcp, upath, sizeof(path), path) > 0 &&
68 * Return true if specified fd maps to a path we're tracing.
71 fdmatch(struct tcb *tcp, int fd, struct path_set *set)
73 char path[PATH_MAX + 1];
74 int n = getfdpath(tcp, fd, path, sizeof(path));
76 return n >= 0 && pathmatch(path, set);
80 * Add a path to the set we're tracing.
81 * Specifying NULL will delete all paths.
84 storepath(const char *path, struct path_set *set)
86 if (pathmatch(path, set))
87 return; /* already in table */
89 if (set->num_selected >= set->size)
91 xgrowarray(set->paths_selected, &set->size,
92 sizeof(set->paths_selected[0]));
94 set->paths_selected[set->num_selected++] = path;
98 * Get path associated with fd.
101 getfdpath(struct tcb *tcp, int fd, char *buf, unsigned bufsize)
103 char linkpath[sizeof("/proc/%u/fd/%u") + 2 * sizeof(int)*3];
109 xsprintf(linkpath, "/proc/%u/fd/%u", tcp->pid, fd);
110 n = readlink(linkpath, buf, bufsize - 1);
112 * NB: if buf is too small, readlink doesn't fail,
113 * it returns truncated result (IOW: n == bufsize - 1).
121 * Add a path to the set we're tracing. Also add the canonicalized
122 * version of the path. Specifying NULL will delete all paths.
125 pathtrace_select_set(const char *path, struct path_set *set)
129 storepath(path, set);
131 rpath = realpath(path, NULL);
136 /* if realpath and specified path are same, we're done */
137 if (strcmp(path, rpath) == 0) {
142 error_msg("Requested path '%s' resolved into '%s'", path, rpath);
143 storepath(rpath, set);
147 match_xselect_args(struct tcb *tcp, const kernel_ulong_t *args,
148 struct path_set *set)
150 /* Kernel truncates arg[0] to int, we do the same. */
151 int nfds = (int) args[0];
152 /* Kernel rejects negative nfds, so we don't parse it either. */
155 /* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
156 if (nfds > 1024*1024)
158 unsigned int fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;
159 fd_set *fds = xmalloc(fdsize);
161 for (unsigned int i = 1; i <= 3; ++i) {
164 if (umoven(tcp, args[i], fdsize, fds) < 0)
166 for (int j = 0;; ++j) {
167 j = next_set_bit(fds, j, nfds);
170 if (fdmatch(tcp, j, set)) {
182 * Return true if syscall accesses a selected path
183 * (or if no paths have been specified for tracing).
186 pathtrace_match_set(struct tcb *tcp, struct path_set *set)
188 const struct_sysent *s;
192 if (!(s->sys_flags & (TRACE_FILE | TRACE_DESC | TRACE_NETWORK)))
196 * Check for special cases where we need to do something
197 * other than test arg[0].
203 case SEN_kexec_file_load:
208 return fdmatch(tcp, tcp->u_arg[0], set) ||
209 fdmatch(tcp, tcp->u_arg[1], set);
217 case SEN_inotify_add_watch:
220 case SEN_name_to_handle_at:
228 return fdmatch(tcp, tcp->u_arg[0], set) ||
229 upathmatch(tcp, tcp->u_arg[1], set);
235 return upathmatch(tcp, tcp->u_arg[0], set) ||
236 upathmatch(tcp, tcp->u_arg[1], set);
241 return upathmatch(tcp, tcp->u_arg[1], set);
246 /* fd, path, fd, path */
247 return fdmatch(tcp, tcp->u_arg[0], set) ||
248 fdmatch(tcp, tcp->u_arg[2], set) ||
249 upathmatch(tcp, tcp->u_arg[1], set) ||
250 upathmatch(tcp, tcp->u_arg[3], set);
252 #if HAVE_ARCH_OLD_MMAP
254 # if HAVE_ARCH_OLD_MMAP_PGOFF
255 case SEN_old_mmap_pgoff:
258 kernel_ulong_t *args =
259 fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 6);
261 return args && fdmatch(tcp, args[4], set);
263 #endif /* HAVE_ARCH_OLD_MMAP */
270 return fdmatch(tcp, tcp->u_arg[4], set);
274 return fdmatch(tcp, tcp->u_arg[1], set) ||
275 upathmatch(tcp, tcp->u_arg[2], set);
277 case SEN_copy_file_range:
279 /* fd, x, fd, x, x, x */
280 return fdmatch(tcp, tcp->u_arg[0], set) ||
281 fdmatch(tcp, tcp->u_arg[2], set);
285 return fdmatch(tcp, tcp->u_arg[2], set);
288 case SEN_fanotify_mark:
290 /* x, x, mask (64 bit), fd, path */
291 unsigned long long mask = 0;
292 int argn = getllval(tcp, &mask, 2);
293 return fdmatch(tcp, tcp->u_arg[argn], set) ||
294 upathmatch(tcp, tcp->u_arg[argn + 1], set);
296 #if HAVE_ARCH_OLD_SELECT
299 kernel_ulong_t *args =
300 fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 5);
302 return args && match_xselect_args(tcp, args, set);
307 return match_xselect_args(tcp, tcp->u_arg, set);
313 kernel_ulong_t start, cur, end;
315 start = tcp->u_arg[0];
316 nfds = tcp->u_arg[1];
318 if (nfds > 1024 * 1024)
320 end = start + sizeof(fds) * nfds;
322 if (nfds == 0 || end < start)
325 for (cur = start; cur < end; cur += sizeof(fds)) {
326 if (umove(tcp, cur, &fds))
328 if (fdmatch(tcp, fds.fd, set))
338 case SEN_epoll_create:
339 case SEN_epoll_create1:
342 case SEN_fanotify_init:
343 case SEN_inotify_init:
344 case SEN_inotify_init1:
345 case SEN_memfd_create:
346 case SEN_mq_getsetattr:
349 case SEN_mq_timedreceive:
350 case SEN_mq_timedsend:
351 case SEN_perf_event_open:
359 case SEN_timerfd_create:
360 case SEN_timerfd_gettime:
361 case SEN_timerfd_settime:
362 case SEN_userfaultfd:
364 * These have TRACE_FILE or TRACE_DESCRIPTOR or TRACE_NETWORK set,
365 * but they don't have any file descriptor or path args to test.
371 * Our fallback position for calls that haven't already
372 * been handled is to just check arg[0].
375 if (s->sys_flags & TRACE_FILE)
376 return upathmatch(tcp, tcp->u_arg[0], set);
378 if (s->sys_flags & (TRACE_DESC | TRACE_NETWORK))
379 return fdmatch(tcp, tcp->u_arg[0], set);