First big update b.cc (gnu coreutils)

research/custom_loader/b.cc

@@ -127,8 +127,8 @@ uint32_t calculate_libname_hash(const libcache *cache, const char *name) {
       char* p = realpath(rpath, 0);
       hash = hash_func(p);
       hash = fnv_hash_extend(&name[6], hash);
-      for (size_t i = 0; i < cache->size; i++) {
+      for (size_t j = 0; j < cache->size; j++) {
-        if (cache->libs[i].hash == hash) {
+        if (cache->libs[j].hash == hash) {
           free(p);
           return hash;
         }
@@ -389,12 +389,29 @@ void *get_export_trie(const void *header, uint32_t &size) {
       const uint32_t offset = *((uint32_t *)ptr + 2);
       size = *((uint32_t *)ptr + 3);
       uint64_t offset_in_linkedit = (uint64_t)offset - linkedit_fileoffset;
+
+      printf("trie: %p\n",linkedit_vmaddr + slice + offset_in_linkedit );
+      if (linkedit_vmaddr + slice + offset_in_linkedit == 0x7ff888187f78) {
+        FILE* f = fopen("../scripts/libsystem_c.dylib", "wb");
+        // fwrite(header, size + linkedit_vmaddr + slice + offset_in_linkedit, 1, f);
+        // fwrite((char*)linkedit_vmaddr + slice + offset_in_linkedit, size, 1, f);
+        fclose(f);
+      }
+
       return (void *)(linkedit_vmaddr + slice + offset_in_linkedit);
     }
     if (cmd == LC_DYLD_INFO_ONLY) {
       const uint32_t offset = *((uint32_t *)ptr + 10);
       size = *((uint32_t *)ptr + 11);
       uint64_t offset_in_linkedit = (uint64_t)offset - linkedit_fileoffset;
+
+      printf("trie: %p\n",linkedit_vmaddr + slice + offset_in_linkedit );
+      if (linkedit_vmaddr + slice + offset_in_linkedit == 0x7ff888187f78) {
+        FILE* f = fopen("../scripts/libsystem_c.bin", "wb");
+        fwrite((char*)linkedit_vmaddr + slice + offset_in_linkedit, size, 1, f);
+        fclose(f);
+      }
+
       return (void *)(linkedit_vmaddr + slice + offset_in_linkedit);
     }
     if (cmd == LC_SEGMENT_64) {
@@ -448,7 +465,7 @@ uint32_t should_follow_symbol(char *&buffer, char *&_find) {
   return is_prefix;
 }
 
-void *find_in_export_trie(const void *header, void *trie, const char *symbol) {
+void *find_in_export_trie(const void *header, void *trie, char *& symbol) {
   uint32_t func = 0;
 
   char *ptr = (char *)trie;
@@ -485,17 +502,23 @@ void *find_in_export_trie(const void *header, void *trie, const char *symbol) {
   }
 
   char count = *(ptr - 1);
-  ptr++; // flags
+  uint8_t flag = *ptr++; // flags
   // uleb128 offset
   decode_uleb128(ptr, &func);
+
+  if (flag == 0x8 /*re-export*/) {
+    symbol = ptr;
+    printf("re-export %s\n", symbol);
+    return 0;
+  }
   return (void *)((char *)header + func);
 }
 
 void *find_in_lib(struct libcache *cache, struct libcache_item *lib,
-                  const char *symbol);
+                  char *& symbol);
 
 void *find_in_reexport(struct libcache *cache, struct libcache_item *lib,
-                       const char *symbol) {
+                       char *& symbol) {
   void *header = lib->header;
   const uint32_t magic = *(uint32_t *)header;
   char *ptr = (char *)header;
@@ -531,12 +554,13 @@ void *find_in_reexport(struct libcache *cache, struct libcache_item *lib,
 }
 
 void *find_in_lib(struct libcache *cache, struct libcache_item *lib,
-                  const char *symbol) {
+                  char *& symbol) {
   void *direct = find_in_export_trie(lib->header, lib->trie, symbol);
   if (direct) {
     return direct;
   }
   // cannot find in directly exported trie, loop through all reexport libs
+  // printf("looking for symbol: %s\n", symbol);
   return find_in_reexport(cache, lib, symbol);
 }
 
@@ -544,7 +568,16 @@ void *custom_dlsym(struct libcache *cache, uint32_t hash, const char *symbol) {
   for (size_t i = 0; i < cache->size; i++) {
     struct libcache_item *cache_lib = &cache->libs[i];
     if (cache_lib->hash == hash) {
-      return find_in_lib(cache, cache_lib, symbol);
+      // if (custom_strcmp(symbol, "_strlen") == 0) {
+      //   return find_in_lib(cache, cache_lib, "__platform_strlen");
+      // }
+      char**  symbol_copy = (char**)&symbol;
+      void* func = find_in_lib(cache, cache_lib, *symbol_copy);
+      if (*symbol_copy != symbol) {
+        printf("symbol found %p %s %s\n", func, *symbol_copy, symbol);
+        func = find_in_lib(cache, cache_lib, *symbol_copy);
+      }
+      return func;
     }
   }
   return 0;
@@ -864,14 +897,20 @@ void build_cache(struct libcache &cache, void *main) {
   typedef int (*dyld_image_count_t)(void);
   typedef char *(*dyld_get_image_name_t)(int);
   typedef void *(*dyld_get_image_header_t)(int);
+
+  char* dyld_image_count_s = "__dyld_image_count";
   int (*dyld_image_count_func)(void) = (dyld_image_count_t)find_in_export_trie(
-      libdyld, libdyld_export_trie, "__dyld_image_count");
+      libdyld, libdyld_export_trie, dyld_image_count_s);
+      
+  char* dyld_get_image_header_s = "__dyld_get_image_header";
   void *(*dyld_get_image_header_func)(int) =
       (dyld_get_image_header_t)find_in_export_trie(libdyld, libdyld_export_trie,
-                                                   "__dyld_get_image_header");
+                                                   dyld_get_image_header_s);
+                                            
+  char* dyld_get_image_name_s = "__dyld_get_image_name";
   char *(*dyld_get_image_name_func)(int) =
       (dyld_get_image_name_t)find_in_export_trie(libdyld, libdyld_export_trie,
-                                                 "__dyld_get_image_name");
+                                                 dyld_get_image_name_s);
 
   cache.size = dyld_image_count_func();
   cache.libs =
@@ -881,7 +920,7 @@ void build_cache(struct libcache &cache, void *main) {
     char *name = dyld_get_image_name_func(i);
     bootstrap_libcache_item(&cache.libs[i], header, name);
     cache.libs[i].hash = calculate_libname_hash(&cache, name);
-    // printf("%p %s\n", header, name);
+    printf("%p %s\n", header, name);
   }
 }
 
@@ -1212,6 +1251,7 @@ void volatile custom_initializer(int argc, const char *const argv[],
     free(custom_initializer_i->constructors);
   }
 
+  printf("initializers completed\n");
   free(custom_initializer_i);
 }