debuggers.hg

view xen/common/symbols.c @ 22848:6341fe0f4e5a

Added tag 4.1.0-rc2 for changeset 9dca60d88c63
author Keir Fraser <keir@xen.org>
date Tue Jan 25 14:06:55 2011 +0000 (2011-01-25)
parents 75e63b73075a
children f5390bd0666b 700ac6445812
line source
1 /*
2 * symbols.c: in-kernel printing of symbolic oopses and stack traces.
3 *
4 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5 *
6 * ChangeLog:
7 *
8 * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
9 * Changed the compression method from stem compression to "table lookup"
10 * compression (see tools/symbols.c for a more complete description)
11 */
13 #include <xen/config.h>
14 #include <xen/symbols.h>
15 #include <xen/kernel.h>
16 #include <xen/init.h>
17 #include <xen/lib.h>
18 #include <xen/string.h>
19 #include <xen/spinlock.h>
21 #ifdef SYMBOLS_ORIGIN
22 extern const unsigned int symbols_offsets[1];
23 #define symbols_address(n) (SYMBOLS_ORIGIN + symbols_offsets[n])
24 #else
25 extern const unsigned long symbols_addresses[];
26 #define symbols_address(n) symbols_addresses[n]
27 #endif
28 extern const unsigned int symbols_num_syms;
29 extern const u8 symbols_names[];
31 extern const u8 symbols_token_table[];
32 extern const u16 symbols_token_index[];
34 extern const unsigned int symbols_markers[];
36 /* expand a compressed symbol data into the resulting uncompressed string,
37 given the offset to where the symbol is in the compressed stream */
38 static unsigned int symbols_expand_symbol(unsigned int off, char *result)
39 {
40 int len, skipped_first = 0;
41 const u8 *tptr, *data;
43 /* get the compressed symbol length from the first symbol byte */
44 data = &symbols_names[off];
45 len = *data;
46 data++;
48 /* update the offset to return the offset for the next symbol on
49 * the compressed stream */
50 off += len + 1;
52 /* for every byte on the compressed symbol data, copy the table
53 entry for that byte */
54 while(len) {
55 tptr = &symbols_token_table[ symbols_token_index[*data] ];
56 data++;
57 len--;
59 while (*tptr) {
60 if(skipped_first) {
61 *result = *tptr;
62 result++;
63 } else
64 skipped_first = 1;
65 tptr++;
66 }
67 }
69 *result = '\0';
71 /* return to offset to the next symbol */
72 return off;
73 }
75 /* find the offset on the compressed stream given and index in the
76 * symbols array */
77 static unsigned int get_symbol_offset(unsigned long pos)
78 {
79 const u8 *name;
80 int i;
82 /* use the closest marker we have. We have markers every 256 positions,
83 * so that should be close enough */
84 name = &symbols_names[ symbols_markers[pos>>8] ];
86 /* sequentially scan all the symbols up to the point we're searching for.
87 * Every symbol is stored in a [<len>][<len> bytes of data] format, so we
88 * just need to add the len to the current pointer for every symbol we
89 * wish to skip */
90 for(i = 0; i < (pos&0xFF); i++)
91 name = name + (*name) + 1;
93 return name - symbols_names;
94 }
96 const char *symbols_lookup(unsigned long addr,
97 unsigned long *symbolsize,
98 unsigned long *offset,
99 char *namebuf)
100 {
101 unsigned long i, low, high, mid;
102 unsigned long symbol_end = 0;
104 namebuf[KSYM_NAME_LEN] = 0;
105 namebuf[0] = 0;
107 if (!is_kernel_text(addr) && !is_kernel_inittext(addr))
108 return NULL;
110 /* do a binary search on the sorted symbols_addresses array */
111 low = 0;
112 high = symbols_num_syms;
114 while (high-low > 1) {
115 mid = (low + high) / 2;
116 if (symbols_address(mid) <= addr) low = mid;
117 else high = mid;
118 }
120 /* search for the first aliased symbol. Aliased symbols are
121 symbols with the same address */
122 while (low && symbols_address(low - 1) == symbols_address(low))
123 --low;
125 /* Grab name */
126 symbols_expand_symbol(get_symbol_offset(low), namebuf);
128 /* Search for next non-aliased symbol */
129 for (i = low + 1; i < symbols_num_syms; i++) {
130 if (symbols_address(i) > symbols_address(low)) {
131 symbol_end = symbols_address(i);
132 break;
133 }
134 }
136 /* if we found no next symbol, we use the end of the section */
137 if (!symbol_end)
138 symbol_end = is_kernel_inittext(addr) ?
139 (unsigned long)_einittext : (unsigned long)_etext;
141 *symbolsize = symbol_end - symbols_address(low);
142 *offset = addr - symbols_address(low);
143 return namebuf;
144 }
146 /* Replace "%s" in format with address, or returns -errno. */
147 void __print_symbol(const char *fmt, unsigned long address)
148 {
149 const char *name;
150 unsigned long offset, size, flags;
152 static DEFINE_SPINLOCK(lock);
153 static char namebuf[KSYM_NAME_LEN+1];
154 #define BUFFER_SIZE sizeof("%s+%#lx/%#lx [%s]") + KSYM_NAME_LEN + \
155 2*(BITS_PER_LONG*3/10) + 1
156 static char buffer[BUFFER_SIZE];
158 spin_lock_irqsave(&lock, flags);
160 name = symbols_lookup(address, &size, &offset, namebuf);
162 if (!name)
163 snprintf(buffer, BUFFER_SIZE, "???");
164 else
165 snprintf(buffer, BUFFER_SIZE, "%s+%#lx/%#lx", name, offset, size);
167 printk(fmt, buffer);
169 spin_unlock_irqrestore(&lock, flags);
170 }