xref: /aosp_15_r20/bionic/libc/bionic/strsignal.cpp (revision 8d67ca893c1523eb926b9080dbe4e2ffd2a27ba1)
1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <signal.h>
30 #include <stdlib.h>
31 #include <string.h>
32 
33 #include "bionic/pthread_internal.h"
34 
35 // Maps regular signals like SIGSEGV to strings like "Segmentation fault".
36 // Signal 0 and all the real-time signals are just nullptr, but that's the ABI.
37 const char* const sys_siglist[NSIG] = {
38 #define __BIONIC_SIGDEF(signal_number, signal_description) [signal_number] = signal_description,
39 #include "private/bionic_sigdefs.h"
40 };
41 
42 // Maps regular signals like SIGSEGV to strings like "SEGV".
43 // Signal 0 and all the real-time signals are just nullptr, but that's the ABI.
44 const char* const sys_signame[NSIG] = {
45 #define __BIONIC_SIGDEF(signal_number, unused) [signal_number] = &(#signal_number)[3],
46 #include "private/bionic_sigdefs.h"
47 };
48 
__strsignal(int signal_number,char * buf,size_t buf_len)49 extern "C" __LIBC_HIDDEN__ const char* __strsignal(int signal_number, char* buf, size_t buf_len) {
50   if (signal_number >= SIGHUP && signal_number < SIGSYS) {
51     return sys_siglist[signal_number];
52   }
53   const char* prefix = "Unknown";
54   if (signal_number >= SIGRTMIN && signal_number <= SIGRTMAX) {
55     prefix = "Real-time";
56     signal_number -= SIGRTMIN;
57   }
58   size_t length = snprintf(buf, buf_len, "%s signal %d", prefix, signal_number);
59   if (length >= buf_len) {
60     return nullptr;
61   }
62   return buf;
63 }
64 
strsignal(int signal_number)65 char* strsignal(int signal_number) {
66   bionic_tls& tls = __get_bionic_tls();
67   return const_cast<char*>(__strsignal(signal_number, tls.strsignal_buf, sizeof(tls.strsignal_buf)));
68 }
69 
sig2str(int sig,char * str)70 int sig2str(int sig, char* str) {
71   if (sig >= SIGHUP && sig <= SIGSYS) {
72     strcpy(str, sys_signame[sig]);
73     return 0;
74   }
75   if (sig == SIGRTMIN) {
76     strcpy(str, "RTMIN");
77     return 0;
78   }
79   if (sig == SIGRTMAX) {
80     strcpy(str, "RTMAX");
81     return 0;
82   }
83   if (sig > SIGRTMIN && sig < SIGRTMAX) {
84     if (sig - SIGRTMIN <= SIGRTMAX - sig) {
85       sprintf(str, "RTMIN+%d", sig - SIGRTMIN);
86     } else {
87       sprintf(str, "RTMAX-%d", SIGRTMAX - sig);
88     }
89     return 0;
90   }
91   return -1;
92 }
93 
str2sig(const char * str,int * sig)94 int str2sig(const char* str, int* sig) {
95   // A name in our list, like "SEGV"?
96   for (size_t i = SIGHUP; i <= SIGSYS; ++i) {
97     if (!strcmp(str, sys_signame[i])) {
98       *sig = i;
99       return 0;
100     }
101   }
102 
103   // The two named special cases?
104   if (!strcmp(str, "RTMIN")) {
105     *sig = SIGRTMIN;
106     return 0;
107   }
108   if (!strcmp(str, "RTMAX")) {
109     *sig = SIGRTMAX;
110     return 0;
111   }
112 
113   // Must be either an integer corresponding to a regular signal such as "9",
114   // or a string of the form "RTMIN+%d" or "RTMAX-%d".
115   int base = 0;
116   if (!strncmp(str, "RTMIN+", 6)) {
117     base = SIGRTMIN;
118     str += 5;
119   } else if (!strncmp(str, "RTMAX-", 6)) {
120     base = SIGRTMAX;
121     str += 5;
122   }
123   char* end = nullptr;
124   errno = 0;
125   int offset = strtol(str, &end, 10);
126   if (errno || *end) return -1;
127 
128   // Reject out of range integers (like "666"),
129   // and out of range real-time signals (like "RTMIN+666" or "RTMAX-666").
130   int result = base + offset;
131   bool regular = (base == 0 && result >= SIGHUP && result <= SIGSYS);
132   bool realtime = (result >= SIGRTMIN && result <= SIGRTMAX);
133   if (!regular && !realtime) return -1;
134 
135   *sig = result;
136   return 0;
137 }
138