minix/commands/swifi/extra.c

   1 /*
   2 Declaration for Linux kernel compatibility
   3 */
   4
   5 #include <assert.h>
   6 #include <stdarg.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <sys/types.h>
  10 #include <sys/ptrace.h>
  11
  12 #include "extra.h"
  13
  14 pid_t victim_pid= -1;
  15 char *victim_exe= NULL;
  16
  17 #define TRAP_BIT        (0x80000000)
  18
  19 static struct nlist *exe_nlist;
  20 static int exe_nlist_n;
  21
  22 void printk(char *fmt, ...)
  23 {
  24         va_list ap;
  25
  26         va_start(ap, fmt);
  27         vfprintf(stderr, fmt, ap);
  28         va_end(ap);
  29 }
  30
  31 int kallsyms_address_to_symbol(db_expr_t off,
  32     const char * *mod_name, unsigned long *mod_start, unsigned long *mod_end,
  33     const char * *sec_name, unsigned long *sec_start, unsigned long *sec_end,
  34     const char * *sym_name, unsigned long *sym_start, unsigned long *sym_end)
  35 {
  36         static char name[64];
  37
  38         int i;
  39         unsigned long btext, etext;
  40         struct nlist *below, *above;
  41
  42         off &= ~TRAP_BIT;
  43         load_nlist(victim_exe, &btext, &etext);
  44         below= above= NULL;
  45         for (i= 0; i<exe_nlist_n; i++)
  46         {
  47                 if (exe_nlist[i].n_type != N_TEXT)
  48                         continue;
  49                 if (exe_nlist[i].n_value <= off)
  50                 {
  51                         if (!below || exe_nlist[i].n_value > below->n_value)
  52                                 below= &exe_nlist[i];
  53                 }
  54                 if (exe_nlist[i].n_value > off)
  55                 {
  56                         if (!above || exe_nlist[i].n_value < above->n_value)
  57                                 above= &exe_nlist[i];
  58                 }
  59         }
  60
  61         btext |= TRAP_BIT;
  62         etext |= TRAP_BIT;
  63
  64         *mod_name = victim_exe;
  65         *mod_start = btext;
  66         *mod_end = etext;
  67         *sec_name = ".text";
  68         *sec_start = btext;
  69         *sec_end = etext;
  70
  71         assert(below && above);
  72
  73         strncpy(name, below->n_name, sizeof(name)-1);
  74         name[sizeof(name)-1]= '\0';
  75         *sym_name= name;
  76
  77         *sym_start= below->n_value | TRAP_BIT;
  78         *sym_end= above->n_value | TRAP_BIT;
  79
  80         return 1;
  81 }
  82
  83 unsigned long text_read_ul(void *addr)
  84 {
  85         int i;
  86         unsigned long value;
  87
  88         for (i= 0; i<sizeof(value); i++)
  89         {
  90                 ((unsigned char *)&value)[i]= text_read_ub((char *)addr+i);
  91         }
  92         return value;
  93 }
  94
  95 unsigned char text_read_ub(void *addr)
  96 {
  97         int v;
  98         unsigned long vaddr;
  99
 100         vaddr= (unsigned long)addr;
 101         vaddr &= ~TRAP_BIT;
 102         v= ptrace(T_READB_INS, victim_pid, (void *)vaddr, 0);
 103         if (v < 0)
 104         {
 105                 fprintf(stderr,
 106         "text_read_ub: trace T_READB_INS failed on pid %d, addr 0x%lx: %s\n",
 107                         victim_pid, vaddr, strerror(errno));
 108                 exit(1);
 109         }
 110         return v;
 111 }
 112
 113 void text_write_ul(void *addr, unsigned long value)
 114 {
 115         int i;
 116
 117         for (i= 0; i<sizeof(value); i++)
 118         {
 119                 text_write_ub((char *)addr+i, ((unsigned char *)&value)[i]);
 120         }
 121 }
 122
 123 void text_write_ub(void *addr, unsigned char value)
 124 {
 125         int v;
 126         unsigned long vaddr;
 127
 128         vaddr= (unsigned long)addr;
 129         vaddr &= ~TRAP_BIT;
 130         v= ptrace(T_WRITEB_INS, victim_pid, (void *)vaddr, value);
 131         if (v < 0)
 132         {
 133                 fprintf(stderr,
 134         "text_read_ub: trace T_WRITEB_INS failed on pid %d, addr 0x%lx: %s\n",
 135                         victim_pid, vaddr, strerror(errno));
 136                 exit(1);
 137         }
 138 }
 139
 140 void load_nlist(exe_name, btextp, etextp)
 141 char *exe_name;
 142 unsigned long *btextp;
 143 unsigned long *etextp;
 144 {
 145         int i;
 146         unsigned long btext, etext;
 147
 148         if (!exe_nlist)
 149         {
 150                 exe_nlist_n= read_nlist(exe_name, &exe_nlist);
 151                 if (exe_nlist_n <= 0)
 152                 {
 153                         if (exe_nlist_n == -1)
 154                         {
 155                                 fprintf(stderr,
 156                                 "error reading name list from '%s': %s\n",
 157                                         exe_name, strerror(errno));
 158                         }
 159                         else
 160                                 fprintf(stderr, "no name list in '%s'\n",
 161                                         exe_name);
 162                         exit(1);
 163                 }
 164         }
 165
 166         if (!btextp && !etextp)
 167                 return;
 168
 169         etext= 0;
 170         btext= (unsigned long)-1;
 171         for (i= 0; i<exe_nlist_n; i++)
 172         {
 173                 if (exe_nlist[i].n_type != N_TEXT)
 174                         continue;
 175                 if (exe_nlist[i].n_value < btext)
 176                         btext= exe_nlist[i].n_value;
 177                 if (exe_nlist[i].n_value > etext)
 178                         etext= exe_nlist[i].n_value;
 179         }
 180
 181         if (btext >= etext)
 182         {
 183                 fprintf(stderr, "Bad btext (0x%lx) or etext (0x%lx) in %s\n",
 184                         btext, etext, exe_name);
 185                 exit(1);
 186         }
 187
 188         btext |= TRAP_BIT;
 189         etext |= TRAP_BIT;
 190
 191         if (btextp)
 192                 *btextp= btext;
 193         if (etextp)
 194                 *etextp= etext;
 195 }