1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
3 */
4
5 #include <rte_debug.h>
6
7 #ifdef RTE_BACKTRACE
8
9 #include <dlfcn.h>
10 #include <execinfo.h>
11 #include <string.h>
12 #include <sys/uio.h>
13 #include <unistd.h>
14
15 #define BACKTRACE_SIZE 256
16
17 /*
18 * Convert number to string and return start of string.
19 * Note: string does not start at beginning of buffer.
20 */
safe_itoa(long val,char * buf,size_t len,unsigned int radix)21 static char *safe_itoa(long val, char *buf, size_t len, unsigned int radix)
22 {
23 char *bp = buf + len;
24 static const char hexdigit[] = "0123456789abcdef";
25
26 *--bp = '\0'; /* Null terminate the string */
27 do {
28 /* if buffer is not big enough, then truncate */
29 if (bp == buf)
30 return bp;
31
32 *--bp = hexdigit[val % radix];
33 val /= radix;
34 } while (val != 0);
35
36 return bp;
37 }
38
39 /*
40 * Dump the stack of the calling core
41 *
42 * To be safe in signal handler requires limiting what functions are
43 * used in this code since may be called from inside libc or
44 * when malloc poll is corrupt.
45 *
46 * Most of libc is therefore not safe, include RTE_LOG (calls syslog);
47 * backtrace_symbols (calls malloc), etc.
48 */
rte_dump_stack(void)49 void rte_dump_stack(void)
50 {
51 void *func[BACKTRACE_SIZE];
52 Dl_info info;
53 char buf1[8], buf2[32], buf3[32], buf4[32];
54 struct iovec iov[10];
55 int i, size;
56
57 size = backtrace(func, BACKTRACE_SIZE);
58
59 for (i = 0; i < size; i++) {
60 struct iovec *io = iov;
61 char *str;
62 uintptr_t base;
63 long offset;
64 void *pc = func[i];
65
66 /*
67 * Macro to put string onto set of iovecs.
68 * cast is to suppress warnings about lose of const qualifier.
69 */
70 #define PUSH_IOV(io, str) { \
71 (io)->iov_base = (char *)(uintptr_t)str; \
72 (io)->iov_len = strlen(str); \
73 ++io; }
74
75 /* output stack frame number */
76 str = safe_itoa(i, buf1, sizeof(buf1), 10);
77 PUSH_IOV(io, str); /* iov[0] */
78 PUSH_IOV(io, ": "); /* iov[1] */
79
80 /* Lookup the symbol information */
81 if (dladdr(pc, &info) == 0) {
82 PUSH_IOV(io, "?? [");
83 } else {
84 const char *fname;
85
86 if (info.dli_fname && *info.dli_fname)
87 fname = info.dli_fname;
88 else
89 fname = "(vdso)";
90 PUSH_IOV(io, fname); /* iov[2] */
91 PUSH_IOV(io, " ("); /* iov[3] */
92
93 if (info.dli_saddr != NULL) {
94 PUSH_IOV(io, info.dli_sname); /* iov[4] */
95 base = (uintptr_t)info.dli_saddr;
96 } else {
97 str = safe_itoa((unsigned long)info.dli_fbase,
98 buf3, sizeof(buf3), 16);
99 PUSH_IOV(io, str);
100 base = (uintptr_t)info.dli_fbase;
101 }
102
103 PUSH_IOV(io, "+0x"); /* iov[5] */
104
105 offset = (uintptr_t)pc - base;
106 str = safe_itoa(offset, buf4, sizeof(buf4), 16);
107 PUSH_IOV(io, str); /* iov[6] */
108
109 PUSH_IOV(io, ") ["); /* iov[7] */
110 }
111
112 str = safe_itoa((unsigned long)pc, buf2, sizeof(buf2), 16);
113 PUSH_IOV(io, str); /* iov[8] */
114 PUSH_IOV(io, "]\n"); /* iov[9] */
115
116 if (writev(STDERR_FILENO, iov, io - iov) < 0)
117 break;
118 #undef PUSH_IOV
119 }
120 }
121
122 #else /* !RTE_BACKTRACE */
123
124 /* stub if not enabled */
rte_dump_stack(void)125 void rte_dump_stack(void) { }
126
127 #endif /* RTE_BACKTRACE */
128