Changeset 0f792c28 in mainline

Timestamp:

2016-04-12T16:59:41Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e2e9a8a

Parents:

3b0f1b9a

Message:

Source for R_*_COPY relocations must be searched for everywhere except for the executable itself (Thanks Jakub)

Location:

uspace/lib/c

Files:

• arch/ia32/src/rtld/reloc.c (modified) (5 diffs)
• generic/dlfcn.c (modified) (1 diff)
• generic/rtld/symbol.c (modified) (5 diffs)
• include/rtld/symbol.h (modified) (1 diff)

uspace/lib/c/arch/ia32/src/rtld/reloc.c

@@ -69 +69 @@
         uint32_t sym_size;
         char *str_tab;
-        
+
         elf_symbol_t *sym_def;
         module_t *dest;
@@ -80 +80 @@
 
         DPRINTF("address: 0x%x, entries: %d\n", (uintptr_t)rt, rt_entries);
-        
+
         for (i = 0; i < rt_entries; ++i) {
 //              DPRINTF("symbol %d: ", i);
@@ -100 +100 @@
 //                      DPRINTF("rel_type: %x, rel_offset: 0x%x\n", rel_type, r_offset);
                         sym_def = symbol_def_find(str_tab + sym->st_name,
-                            m, &dest);
+                            m, ssf_none, &dest);
 //                      DPRINTF("dest name: '%s'\n", dest->dyn.soname);
 //                      DPRINTF("dest bias: 0x%x\n", dest->bias);
@@ -137 +137 @@
                         /*
                          * Copy symbol data from shared object to specified
-                         * location.
+                         * location. Need to find the 'source', i.e. the
+                         * other instance of the object than the one in the
+                         * executable program.
                          */
                         DPRINTF("fixup R_386_COPY (s)\n");
+
+                        sym_def = symbol_def_find(str_tab + sym->st_name,
+                            m, ssf_noroot, &dest);
+
+                        if (sym_def) {
+                                sym_addr = (uint32_t)
+                                    symbol_get_addr(sym_def, dest);
+                        } else {
+                                printf("Source definition of '%s' not found.\n",
+                                    str_tab + sym->st_name);
+                                continue;
+                        }
+
                         sym_size = sym->st_size;
                         if (sym_size != sym_def->st_size) {
@@ -147 +162 @@
                                         sym_size = sym_def->st_size;
                         }
+
                         memcpy(r_ptr, (const void *)sym_addr, sym_size);
                         break;
-                        
+
                 case R_386_RELATIVE:
                         DPRINTF("fixup R_386_RELATIVE (b+a)\n");

uspace/lib/c/generic/dlfcn.c

@@ -81 +81 @@
 
         printf("dlsym(0x%lx, \"%s\")\n", (long)mod, sym_name);
-        sd = symbol_bfs_find(sym_name, (module_t *) mod, &sm);
+        sd = symbol_bfs_find(sym_name, (module_t *) mod, ssf_none, &sm);
         if (sd != NULL) {
                 return symbol_get_addr(sd, sm);

uspace/lib/c/generic/rtld/symbol.c

@@ -111 +111 @@
  * @param name          Name of the symbol to search for.
  * @param start         Module in which to start the search..
+ * @param flags         @c ssf_none or @c ssf_noroot to not look for the symbol
+ *                      in @a start
  * @param mod           (output) Will be filled with a pointer to the module 
  *                      that contains the symbol.
  */
-elf_symbol_t *symbol_bfs_find(const char *name, module_t *start, module_t **mod)
+elf_symbol_t *symbol_bfs_find(const char *name, module_t *start,
+    symbol_search_flags_t flags, module_t **mod)
 {
         module_t *m, *dm;
@@ -145 +148 @@
                 list_remove(&m->queue_link);
 
-                s = def_find_in_module(name, m);
-                if (s != NULL) {
-                        /* Symbol found */
-                        sym = s;
-                        *mod = m;
-                        break;
+                /* If ssf_noroot is specified, do not look in start module */
+                if (m != start || (flags & ssf_noroot) == 0) { 
+                        s = def_find_in_module(name, m);
+                        if (s != NULL) {
+                                /* Symbol found */
+                                sym = s;
+                                *mod = m;
+                                break;
+                        }
                 }
 
@@ -179 +185 @@
 
 
-/** Find the definition of a symbol..
+/** Find the definition of a symbol.
  *
  * By definition in System V ABI, if module origin has the flag DT_SYMBOLIC,
@@ -188 +194 @@
  * @param name          Name of the symbol to search for.
  * @param origin        Module in which the dependency originates.
+ * @param flags         @c ssf_none or @c ssf_noroot to not look for the symbol
+ *                      in the executable program.
  * @param mod           (output) Will be filled with a pointer to the module 
  *                      that contains the symbol.
  */
-elf_symbol_t *symbol_def_find(const char *name, module_t *origin, module_t **mod)
+elf_symbol_t *symbol_def_find(const char *name, module_t *origin,
+    symbol_search_flags_t flags, module_t **mod)
 {
         elf_symbol_t *s;
@@ -212 +221 @@
         if (runtime_env->program) {
                 /* Program is dynamic -- start with program as root. */
-                return symbol_bfs_find(name, runtime_env->program, mod);
+                return symbol_bfs_find(name, runtime_env->program, flags, mod);
         } else {
                 /* Program is static -- start with @a origin as root. */
-                return symbol_bfs_find(name, origin, mod);
+                return symbol_bfs_find(name, origin, ssf_none, mod);
         }
 }

uspace/lib/c/include/rtld/symbol.h

@@ -39 +39 @@
 #include <rtld/rtld.h>
 
-elf_symbol_t *symbol_bfs_find(const char *name, module_t *start, module_t **mod);
-elf_symbol_t *symbol_def_find(const char *name, module_t *origin, module_t **mod);
-void *symbol_get_addr(elf_symbol_t *sym, module_t *m);
+/** Symbol search flags */
+typedef enum {
+        /** No flags */
+        ssf_none = 0,
+        /** Do not search tree root */
+        ssf_noroot = 0x1
+} symbol_search_flags_t;
+
+extern elf_symbol_t *symbol_bfs_find(const char *, module_t *,
+    symbol_search_flags_t, module_t **);
+extern elf_symbol_t *symbol_def_find(const char *, module_t *,
+    symbol_search_flags_t, module_t **);
+extern void *symbol_get_addr(elf_symbol_t *, module_t *);
 
 #endif