1 /* system/debuggerd/utility.c
2 **
3 ** Copyright 2008, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17
18 #include <stddef.h>
19 #include <stdbool.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <errno.h>
23 #include <unistd.h>
24 #include <signal.h>
25 #include <log/logd.h>
26 #include <sys/ptrace.h>
27 #include <sys/wait.h>
28 #include <arpa/inet.h>
29 #include <assert.h>
30
31 #include "utility.h"
32
33 const int sleep_time_usec = 50000; /* 0.05 seconds */
34 const int max_total_sleep_usec = 10000000; /* 10 seconds */
35
write_to_am(int fd,const char * buf,int len)36 static int write_to_am(int fd, const char* buf, int len) {
37 int to_write = len;
38 while (to_write > 0) {
39 int written = TEMP_FAILURE_RETRY( write(fd, buf + len - to_write, to_write) );
40 if (written < 0) {
41 /* hard failure */
42 LOG("AM write failure (%d / %s)\n", errno, strerror(errno));
43 return -1;
44 }
45 to_write -= written;
46 }
47 return len;
48 }
49
_LOG(log_t * log,int scopeFlags,const char * fmt,...)50 void _LOG(log_t* log, int scopeFlags, const char *fmt, ...) {
51 char buf[512];
52 bool want_tfd_write;
53 bool want_log_write;
54 bool want_amfd_write;
55 int len = 0;
56
57 va_list ap;
58 va_start(ap, fmt);
59
60 // where is the information going to go?
61 want_tfd_write = log && log->tfd >= 0;
62 want_log_write = IS_AT_FAULT(scopeFlags) && (!log || !log->quiet);
63 want_amfd_write = IS_AT_FAULT(scopeFlags) && !IS_SENSITIVE(scopeFlags) && log && log->amfd >= 0;
64
65 // if we're going to need the literal string, generate it once here
66 if (want_tfd_write || want_amfd_write) {
67 vsnprintf(buf, sizeof(buf), fmt, ap);
68 len = strlen(buf);
69 }
70
71 if (want_tfd_write) {
72 write(log->tfd, buf, len);
73 }
74
75 if (want_log_write) {
76 // whatever goes to logcat also goes to the Activity Manager
77 __android_log_vprint(ANDROID_LOG_INFO, "DEBUG", fmt, ap);
78 if (want_amfd_write && len > 0) {
79 int written = write_to_am(log->amfd, buf, len);
80 if (written <= 0) {
81 // timeout or other failure on write; stop informing the activity manager
82 log->amfd = -1;
83 }
84 }
85 }
86 va_end(ap);
87 }
88
wait_for_signal(pid_t tid,int * total_sleep_time_usec)89 int wait_for_signal(pid_t tid, int* total_sleep_time_usec) {
90 for (;;) {
91 int status;
92 pid_t n = waitpid(tid, &status, __WALL | WNOHANG);
93 if (n < 0) {
94 if(errno == EAGAIN) continue;
95 LOG("waitpid failed: %s\n", strerror(errno));
96 return -1;
97 } else if (n > 0) {
98 XLOG("waitpid: n=%d status=%08x\n", n, status);
99 if (WIFSTOPPED(status)) {
100 return WSTOPSIG(status);
101 } else {
102 LOG("unexpected waitpid response: n=%d, status=%08x\n", n, status);
103 return -1;
104 }
105 }
106
107 if (*total_sleep_time_usec > max_total_sleep_usec) {
108 LOG("timed out waiting for tid=%d to die\n", tid);
109 return -1;
110 }
111
112 /* not ready yet */
113 XLOG("not ready yet\n");
114 usleep(sleep_time_usec);
115 *total_sleep_time_usec += sleep_time_usec;
116 }
117 }
118
wait_for_stop(pid_t tid,int * total_sleep_time_usec)119 void wait_for_stop(pid_t tid, int* total_sleep_time_usec) {
120 siginfo_t si;
121 while (TEMP_FAILURE_RETRY(ptrace(PTRACE_GETSIGINFO, tid, 0, &si)) < 0 && errno == ESRCH) {
122 if (*total_sleep_time_usec > max_total_sleep_usec) {
123 LOG("timed out waiting for tid=%d to stop\n", tid);
124 break;
125 }
126
127 usleep(sleep_time_usec);
128 *total_sleep_time_usec += sleep_time_usec;
129 }
130 }
131