debuggers.hg

annotate 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
rev   line source
kaf24@5862 1 /*
kaf24@5862 2 * symbols.c: in-kernel printing of symbolic oopses and stack traces.
kaf24@5862 3 *
kaf24@5862 4 * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
kaf24@5862 5 *
kaf24@5862 6 * ChangeLog:
kaf24@5862 7 *
kaf24@5862 8 * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com>
kaf24@5862 9 * Changed the compression method from stem compression to "table lookup"
kaf24@5862 10 * compression (see tools/symbols.c for a more complete description)
kaf24@5862 11 */
kaf24@5862 12
kaf24@5862 13 #include <xen/config.h>
kaf24@5862 14 #include <xen/symbols.h>
kaf24@13252 15 #include <xen/kernel.h>
kaf24@5862 16 #include <xen/init.h>
kaf24@5862 17 #include <xen/lib.h>
kaf24@5862 18 #include <xen/string.h>
keir@14721 19 #include <xen/spinlock.h>
kaf24@5862 20
keir@19971 21 #ifdef SYMBOLS_ORIGIN
keir@19971 22 extern const unsigned int symbols_offsets[1];
keir@19971 23 #define symbols_address(n) (SYMBOLS_ORIGIN + symbols_offsets[n])
keir@19971 24 #else
keir@19971 25 extern const unsigned long symbols_addresses[];
keir@19971 26 #define symbols_address(n) symbols_addresses[n]
keir@19971 27 #endif
keir@19971 28 extern const unsigned int symbols_num_syms;
keir@19971 29 extern const u8 symbols_names[];
kaf24@5862 30
keir@19971 31 extern const u8 symbols_token_table[];
keir@19971 32 extern const u16 symbols_token_index[];
kaf24@5862 33
keir@19971 34 extern const unsigned int symbols_markers[];
kaf24@5862 35
kaf24@5862 36 /* expand a compressed symbol data into the resulting uncompressed string,
kaf24@5862 37 given the offset to where the symbol is in the compressed stream */
kaf24@5862 38 static unsigned int symbols_expand_symbol(unsigned int off, char *result)
kaf24@5862 39 {
kaf24@5862 40 int len, skipped_first = 0;
keir@19971 41 const u8 *tptr, *data;
kaf24@5862 42
kaf24@5862 43 /* get the compressed symbol length from the first symbol byte */
kaf24@5862 44 data = &symbols_names[off];
kaf24@5862 45 len = *data;
kaf24@5862 46 data++;
kaf24@5862 47
kaf24@5862 48 /* update the offset to return the offset for the next symbol on
kaf24@5862 49 * the compressed stream */
kaf24@5862 50 off += len + 1;
kaf24@5862 51
kaf24@5862 52 /* for every byte on the compressed symbol data, copy the table
kaf24@5862 53 entry for that byte */
kaf24@5862 54 while(len) {
kaf24@5862 55 tptr = &symbols_token_table[ symbols_token_index[*data] ];
kaf24@5862 56 data++;
kaf24@5862 57 len--;
kaf24@5862 58
kaf24@5862 59 while (*tptr) {
kaf24@5862 60 if(skipped_first) {
kaf24@5862 61 *result = *tptr;
kaf24@5862 62 result++;
kaf24@5862 63 } else
kaf24@5862 64 skipped_first = 1;
kaf24@5862 65 tptr++;
kaf24@5862 66 }
kaf24@5862 67 }
kaf24@5862 68
kaf24@5862 69 *result = '\0';
kaf24@5862 70
kaf24@5862 71 /* return to offset to the next symbol */
kaf24@5862 72 return off;
kaf24@5862 73 }
kaf24@5862 74
kaf24@5862 75 /* find the offset on the compressed stream given and index in the
kaf24@5862 76 * symbols array */
kaf24@5862 77 static unsigned int get_symbol_offset(unsigned long pos)
kaf24@5862 78 {
keir@19971 79 const u8 *name;
kaf24@5862 80 int i;
kaf24@5862 81
kaf24@5862 82 /* use the closest marker we have. We have markers every 256 positions,
kaf24@5862 83 * so that should be close enough */
kaf24@5862 84 name = &symbols_names[ symbols_markers[pos>>8] ];
kaf24@5862 85
kaf24@5862 86 /* sequentially scan all the symbols up to the point we're searching for.
kaf24@5862 87 * Every symbol is stored in a [<len>][<len> bytes of data] format, so we
kaf24@5862 88 * just need to add the len to the current pointer for every symbol we
kaf24@5862 89 * wish to skip */
kaf24@5862 90 for(i = 0; i < (pos&0xFF); i++)
kaf24@5862 91 name = name + (*name) + 1;
kaf24@5862 92
kaf24@5862 93 return name - symbols_names;
kaf24@5862 94 }
kaf24@5862 95
kaf24@5862 96 const char *symbols_lookup(unsigned long addr,
kaf24@5862 97 unsigned long *symbolsize,
kaf24@5862 98 unsigned long *offset,
kaf24@5862 99 char *namebuf)
kaf24@5862 100 {
kaf24@5862 101 unsigned long i, low, high, mid;
kaf24@5862 102 unsigned long symbol_end = 0;
kaf24@5862 103
kaf24@5862 104 namebuf[KSYM_NAME_LEN] = 0;
kaf24@5862 105 namebuf[0] = 0;
kaf24@5862 106
kaf24@13252 107 if (!is_kernel_text(addr) && !is_kernel_inittext(addr))
kaf24@5862 108 return NULL;
kaf24@5862 109
kaf24@5862 110 /* do a binary search on the sorted symbols_addresses array */
kaf24@5862 111 low = 0;
kaf24@5862 112 high = symbols_num_syms;
kaf24@5862 113
kaf24@5862 114 while (high-low > 1) {
kaf24@5862 115 mid = (low + high) / 2;
keir@19971 116 if (symbols_address(mid) <= addr) low = mid;
kaf24@5862 117 else high = mid;
kaf24@5862 118 }
kaf24@5862 119
kaf24@5862 120 /* search for the first aliased symbol. Aliased symbols are
kaf24@5862 121 symbols with the same address */
keir@19971 122 while (low && symbols_address(low - 1) == symbols_address(low))
kaf24@5862 123 --low;
kaf24@5862 124
kaf24@5862 125 /* Grab name */
kaf24@5862 126 symbols_expand_symbol(get_symbol_offset(low), namebuf);
kaf24@5862 127
kaf24@5862 128 /* Search for next non-aliased symbol */
kaf24@5862 129 for (i = low + 1; i < symbols_num_syms; i++) {
keir@19971 130 if (symbols_address(i) > symbols_address(low)) {
keir@19971 131 symbol_end = symbols_address(i);
kaf24@5862 132 break;
kaf24@5862 133 }
kaf24@5862 134 }
kaf24@5862 135
kaf24@5862 136 /* if we found no next symbol, we use the end of the section */
kaf24@5862 137 if (!symbol_end)
kaf24@13252 138 symbol_end = is_kernel_inittext(addr) ?
kaf24@13252 139 (unsigned long)_einittext : (unsigned long)_etext;
kaf24@5862 140
keir@19971 141 *symbolsize = symbol_end - symbols_address(low);
keir@19971 142 *offset = addr - symbols_address(low);
kaf24@5862 143 return namebuf;
kaf24@5862 144 }
kaf24@5862 145
kaf24@5862 146 /* Replace "%s" in format with address, or returns -errno. */
kaf24@5862 147 void __print_symbol(const char *fmt, unsigned long address)
kaf24@5862 148 {
kaf24@5862 149 const char *name;
keir@14721 150 unsigned long offset, size, flags;
kfraser@13697 151
keir@14721 152 static DEFINE_SPINLOCK(lock);
keir@14721 153 static char namebuf[KSYM_NAME_LEN+1];
kfraser@13697 154 #define BUFFER_SIZE sizeof("%s+%#lx/%#lx [%s]") + KSYM_NAME_LEN + \
kfraser@13697 155 2*(BITS_PER_LONG*3/10) + 1
keir@14721 156 static char buffer[BUFFER_SIZE];
keir@14721 157
keir@14721 158 spin_lock_irqsave(&lock, flags);
kaf24@5862 159
kaf24@5862 160 name = symbols_lookup(address, &size, &offset, namebuf);
kaf24@5862 161
kaf24@5862 162 if (!name)
kfraser@13697 163 snprintf(buffer, BUFFER_SIZE, "???");
kaf24@5862 164 else
kfraser@13697 165 snprintf(buffer, BUFFER_SIZE, "%s+%#lx/%#lx", name, offset, size);
kaf24@5862 166
kaf24@5862 167 printk(fmt, buffer);
keir@14721 168
keir@14721 169 spin_unlock_irqrestore(&lock, flags);
kaf24@5862 170 }