1 #include <prelinkmap.h> 2 #include <debug.h> 3 #include <errno.h> 4 #include <string.h> 5 #include <libgen.h> 6 #include <ctype.h> 7 8 typedef struct mapentry mapentry; 9 10 #define MAX_ALIASES 10 11 12 struct mapentry 13 { 14 mapentry *next; 15 unsigned base; 16 char *names[MAX_ALIASES]; 17 int num_names; 18 }; 19 20 static mapentry *maplist = 0; 21 22 /* These values limit the address range within which we prelinked libraries 23 reside. The limit is not set in stone, but should be observed in the 24 prelink map, or the prelink step will fail. 25 */ 26 27 #define PRELINK_MIN 0x90000000 28 #define PRELINK_MAX 0xBFFFFFFF 29 30 void pm_init(const char *file) 31 { 32 unsigned line = 0; 33 char buf[256]; 34 char *x; 35 FILE *fp; 36 mapentry *me; 37 unsigned last = -1UL; 38 39 fp = fopen(file, "r"); 40 FAILIF(fp == NULL, "Error opening file %s: %s (%d)\n", 41 file, strerror(errno), errno); 42 43 while(fgets(buf, 256, fp)){ 44 x = buf; 45 line++; 46 47 /* eat leading whitespace */ 48 while(isspace(*x)) x++; 49 50 /* comment or blank line? skip! */ 51 if(*x == '#') continue; 52 if(*x == 0) continue; 53 54 /* skip name */ 55 while(*x && !isspace(*x)) x++; 56 57 if(*x) { 58 *x++ = 0; 59 /* skip space before address */ 60 while(*x && isspace(*x)) x++; 61 } 62 63 /* no address? complain. */ 64 if(*x == 0) { 65 fprintf(stderr,"warning: %s:%d no base address specified\n", 66 file, line); 67 continue; 68 } 69 70 if (isalpha(*x)) { 71 /* Assume that this is an alias, and look through the list of 72 already-installed libraries. 73 */ 74 me = maplist; 75 while(me) { 76 /* The strlen() call ignores the newline at the end of x */ 77 if (!strncmp(me->names[0], x, strlen(me->names[0]))) { 78 PRINT("Aliasing library %s to %s at %08x\n", 79 buf, x, me->base); 80 break; 81 } 82 me = me->next; 83 } 84 FAILIF(!me, "Nonexistent alias %s -> %s\n", buf, x); 85 } 86 else { 87 unsigned n = strtoul(x, 0, 16); 88 /* Note that this is not the only bounds check. If a library's 89 size exceeds its slot as defined in the prelink map, the 90 prelinker will exit with an error. See 91 pm_report_library_size_in_memory(). 92 */ 93 FAILIF((n < PRELINK_MIN) || (n > PRELINK_MAX), 94 "%s:%d base 0x%08x out of range.\n", 95 file, line, n); 96 97 me = malloc(sizeof(mapentry)); 98 FAILIF(me == NULL, "Out of memory parsing %s\n", file); 99 100 FAILIF(last <= n, "The prelink map is not in descending order " 101 "at entry %s (%08x)!\n", buf, n); 102 last = n; 103 104 me->base = n; 105 me->next = maplist; 106 me->num_names = 0; 107 maplist = me; 108 } 109 110 FAILIF(me->num_names >= MAX_ALIASES, 111 "Too many aliases for library %s, maximum is %d.\n", 112 me->names[0], 113 MAX_ALIASES); 114 me->names[me->num_names] = strdup(buf); 115 me->num_names++; 116 } 117 118 fclose(fp); 119 } 120 121 /* apriori() calls this function when it determine the size of a library 122 in memory. pm_report_library_size_in_memory() makes sure that the library 123 fits in the slot provided by the prelink map. 124 */ 125 void pm_report_library_size_in_memory(const char *name, 126 off_t fsize) 127 { 128 char *x; 129 mapentry *me; 130 int n; 131 132 x = strrchr(name,'/'); 133 if(x) name = x+1; 134 135 for(me = maplist; me; me = me->next){ 136 for (n = 0; n < me->num_names; n++) { 137 if(!strcmp(name, me->names[n])) { 138 off_t slot = me->next ? me->next->base : PRELINK_MAX; 139 slot -= me->base; 140 FAILIF(fsize > slot, 141 "prelink map error: library %s@0x%08x is too big " 142 "at %lld bytes, it runs %lld bytes into " 143 "library %s@0x%08x!\n", 144 me->names[0], me->base, fsize, fsize - slot, 145 me->next->names[0], me->next->base); 146 return; 147 } 148 } 149 } 150 151 FAILIF(1, "library '%s' not in prelink map\n", name); 152 } 153 154 unsigned pm_get_next_link_address(const char *lookup_name) 155 { 156 char *x; 157 mapentry *me; 158 int n; 159 160 x = strrchr(lookup_name,'/'); 161 if(x) lookup_name = x+1; 162 163 for(me = maplist; me; me = me->next) 164 for (n = 0; n < me->num_names; n++) 165 if(!strcmp(lookup_name, me->names[n])) 166 return me->base; 167 168 FAILIF(1, "library '%s' not in prelink map\n", lookup_name); 169 return 0; 170 } 171