xref: /qemu/bsd-user/strace.c (revision b2a3cbb8)
1 /*
2  *  System call tracing and debugging
3  *
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (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
13  *  GNU General Public License for more details.
14  *
15  *  You should have received a copy of the GNU General Public License
16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "qemu/osdep.h"
20 #include <sys/select.h>
21 #include <sys/syscall.h>
22 #include <sys/ioccom.h>
23 #include <ctype.h>
24 
25 #include "qemu.h"
26 
27 #include "os-strace.h"  /* OS dependent strace print functions */
28 
29 int do_strace;
30 
31 /*
32  * Utility functions
33  */
34 static const char *
35 get_comma(int last)
36 {
37     return (last) ? "" : ",";
38 }
39 
40 /*
41  * Prints out raw parameter using given format.  Caller needs
42  * to do byte swapping if needed.
43  */
44 static void
45 print_raw_param(const char *fmt, abi_long param, int last)
46 {
47     char format[64];
48 
49     (void)snprintf(format, sizeof(format), "%s%s", fmt, get_comma(last));
50     gemu_log(format, param);
51 }
52 
53 static void print_sysctl(const struct syscallname *name, abi_long arg1,
54         abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5,
55         abi_long arg6)
56 {
57     uint32_t i;
58     int32_t *namep;
59 
60     gemu_log("%s({ ", name->name);
61     namep = lock_user(VERIFY_READ, arg1, sizeof(int32_t) * arg2, 1);
62     if (namep) {
63         int32_t *p = namep;
64 
65         for (i = 0; i < (uint32_t)arg2; i++) {
66             gemu_log("%d ", tswap32(*p++));
67         }
68         unlock_user(namep, arg1, 0);
69     }
70     gemu_log("}, %u, 0x" TARGET_ABI_FMT_lx ", 0x" TARGET_ABI_FMT_lx ", 0x"
71         TARGET_ABI_FMT_lx ", 0x" TARGET_ABI_FMT_lx ")",
72         (uint32_t)arg2, arg3, arg4, arg5, arg6);
73 }
74 
75 static void print_execve(const struct syscallname *name, abi_long arg1,
76         abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5,
77         abi_long arg6)
78 {
79     abi_ulong arg_ptr_addr;
80     char *s;
81 
82     s = lock_user_string(arg1);
83     if (s == NULL) {
84         return;
85     }
86     gemu_log("%s(\"%s\",{", name->name, s);
87     unlock_user(s, arg1, 0);
88 
89     for (arg_ptr_addr = arg2; ; arg_ptr_addr += sizeof(abi_ulong)) {
90         abi_ulong *arg_ptr, arg_addr;
91 
92         arg_ptr = lock_user(VERIFY_READ, arg_ptr_addr, sizeof(abi_ulong), 1);
93         if (!arg_ptr) {
94             return;
95         }
96         arg_addr = tswapl(*arg_ptr);
97         unlock_user(arg_ptr, arg_ptr_addr, 0);
98         if (!arg_addr) {
99             break;
100         }
101         if ((s = lock_user_string(arg_addr))) {
102             gemu_log("\"%s\",", s);
103             unlock_user(s, arg_addr, 0);
104         }
105     }
106     gemu_log("NULL})");
107 }
108 
109 static void print_ioctl(const struct syscallname *name,
110         abi_long arg1, abi_long arg2, abi_long arg3, abi_long arg4,
111         abi_long arg5, abi_long arg6)
112 {
113     /* Decode the ioctl request */
114     gemu_log("%s(%d, 0x%0lx { IO%s%s GRP:0x%x('%c') CMD:%d LEN:%d }, 0x"
115             TARGET_ABI_FMT_lx ", ...)",
116             name->name,
117             (int)arg1,
118             (unsigned long)arg2,
119             arg2 & IOC_OUT ? "R" : "",
120             arg2 & IOC_IN ? "W" : "",
121             (unsigned)IOCGROUP(arg2),
122             isprint(IOCGROUP(arg2)) ? (char)IOCGROUP(arg2) : '?',
123             (int)arg2 & 0xFF,
124             (int)IOCPARM_LEN(arg2),
125             arg3);
126 }
127 
128 static void print_sysarch(const struct syscallname *name, abi_long arg1,
129         abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5,
130         abi_long arg6)
131 {
132     /* This is os dependent. */
133     do_os_print_sysarch(name, arg1, arg2, arg3, arg4, arg5, arg6);
134 }
135 
136 /*
137  * Variants for the return value output function
138  */
139 
140 static void print_syscall_ret_addr(const struct syscallname *name, abi_long ret)
141 {
142     if (ret == -1) {
143         gemu_log(" = -1 errno=%d (%s)\n", errno, strerror(errno));
144     } else {
145         gemu_log(" = 0x" TARGET_ABI_FMT_lx "\n", ret);
146     }
147 }
148 
149 /*
150  * An array of all of the syscalls we know about
151  */
152 
153 static const struct syscallname freebsd_scnames[] = {
154 #include "freebsd/strace.list"
155 };
156 static const struct syscallname netbsd_scnames[] = {
157 #include "netbsd/strace.list"
158 };
159 static const struct syscallname openbsd_scnames[] = {
160 #include "openbsd/strace.list"
161 };
162 
163 static void print_syscall(int num, const struct syscallname *scnames,
164         unsigned int nscnames, abi_long arg1, abi_long arg2, abi_long arg3,
165         abi_long arg4, abi_long arg5, abi_long arg6)
166 {
167     unsigned int i;
168     const char *format="%s(" TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld ","
169         TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld ","
170         TARGET_ABI_FMT_ld ")";
171 
172     gemu_log("%d ", getpid() );
173 
174     for (i = 0; i < nscnames; i++) {
175         if (scnames[i].nr == num) {
176             if (scnames[i].call != NULL) {
177                 scnames[i].call(&scnames[i], arg1, arg2, arg3, arg4, arg5,
178                         arg6);
179             } else {
180                 /* XXX: this format system is broken because it uses
181                    host types and host pointers for strings */
182                 if (scnames[i].format != NULL) {
183                     format = scnames[i].format;
184                 }
185                 gemu_log(format, scnames[i].name, arg1, arg2, arg3, arg4, arg5,
186                         arg6);
187             }
188             return;
189         }
190     }
191     gemu_log("Unknown syscall %d\n", num);
192 }
193 
194 static void print_syscall_ret(int num, abi_long ret,
195         const struct syscallname *scnames, unsigned int nscnames)
196 {
197     unsigned int i;
198 
199     for (i = 0; i < nscnames; i++) {
200         if (scnames[i].nr == num) {
201             if (scnames[i].result != NULL) {
202                 scnames[i].result(&scnames[i], ret);
203             } else {
204                 if (ret < 0) {
205                     gemu_log(" = -1 errno=" TARGET_ABI_FMT_ld " (%s)\n", -ret,
206                              strerror(-ret));
207                 } else {
208                     gemu_log(" = " TARGET_ABI_FMT_ld "\n", ret);
209                 }
210             }
211             break;
212         }
213     }
214 }
215 
216 /*
217  * The public interface to this module.
218  */
219 void print_freebsd_syscall(int num, abi_long arg1, abi_long arg2, abi_long arg3,
220         abi_long arg4, abi_long arg5, abi_long arg6)
221 {
222 
223     print_syscall(num, freebsd_scnames, ARRAY_SIZE(freebsd_scnames), arg1, arg2,
224             arg3, arg4, arg5, arg6);
225 }
226 
227 void print_freebsd_syscall_ret(int num, abi_long ret)
228 {
229 
230     print_syscall_ret(num, ret, freebsd_scnames, ARRAY_SIZE(freebsd_scnames));
231 }
232 
233 void print_netbsd_syscall(int num, abi_long arg1, abi_long arg2, abi_long arg3,
234         abi_long arg4, abi_long arg5, abi_long arg6)
235 {
236 
237     print_syscall(num, netbsd_scnames, ARRAY_SIZE(netbsd_scnames),
238                   arg1, arg2, arg3, arg4, arg5, arg6);
239 }
240 
241 void print_netbsd_syscall_ret(int num, abi_long ret)
242 {
243 
244     print_syscall_ret(num, ret, netbsd_scnames, ARRAY_SIZE(netbsd_scnames));
245 }
246 
247 void print_openbsd_syscall(int num, abi_long arg1, abi_long arg2, abi_long arg3,
248         abi_long arg4, abi_long arg5, abi_long arg6)
249 {
250 
251     print_syscall(num, openbsd_scnames, ARRAY_SIZE(openbsd_scnames), arg1, arg2,
252             arg3, arg4, arg5, arg6);
253 }
254 
255 void print_openbsd_syscall_ret(int num, abi_long ret)
256 {
257 
258     print_syscall_ret(num, ret, openbsd_scnames, ARRAY_SIZE(openbsd_scnames));
259 }
260 
261 static void
262 print_signal(abi_ulong arg, int last)
263 {
264     const char *signal_name = NULL;
265     switch (arg) {
266     case TARGET_SIGHUP:
267         signal_name = "SIGHUP";
268         break;
269     case TARGET_SIGINT:
270         signal_name = "SIGINT";
271         break;
272     case TARGET_SIGQUIT:
273         signal_name = "SIGQUIT";
274         break;
275     case TARGET_SIGILL:
276         signal_name = "SIGILL";
277         break;
278     case TARGET_SIGABRT:
279         signal_name = "SIGABRT";
280         break;
281     case TARGET_SIGFPE:
282         signal_name = "SIGFPE";
283         break;
284     case TARGET_SIGKILL:
285         signal_name = "SIGKILL";
286         break;
287     case TARGET_SIGSEGV:
288         signal_name = "SIGSEGV";
289         break;
290     case TARGET_SIGPIPE:
291         signal_name = "SIGPIPE";
292         break;
293     case TARGET_SIGALRM:
294         signal_name = "SIGALRM";
295         break;
296     case TARGET_SIGTERM:
297         signal_name = "SIGTERM";
298         break;
299     case TARGET_SIGUSR1:
300         signal_name = "SIGUSR1";
301         break;
302     case TARGET_SIGUSR2:
303         signal_name = "SIGUSR2";
304         break;
305     case TARGET_SIGCHLD:
306         signal_name = "SIGCHLD";
307         break;
308     case TARGET_SIGCONT:
309         signal_name = "SIGCONT";
310         break;
311     case TARGET_SIGSTOP:
312         signal_name = "SIGSTOP";
313         break;
314     case TARGET_SIGTTIN:
315         signal_name = "SIGTTIN";
316         break;
317     case TARGET_SIGTTOU:
318         signal_name = "SIGTTOU";
319         break;
320     }
321     if (signal_name == NULL) {
322         print_raw_param("%ld", arg, last);
323         return;
324     }
325     gemu_log("%s%s", signal_name, get_comma(last));
326 }
327 
328 void print_taken_signal(int target_signum, const target_siginfo_t *tinfo)
329 {
330     /*
331      * Print the strace output for a signal being taken:
332      * --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
333      */
334     gemu_log("%d ", getpid());
335     gemu_log("--- ");
336     print_signal(target_signum, 1);
337     gemu_log(" ---\n");
338 }
339