Changeset 6adb775f in mainline for uspace/lib/c/generic/rtld

Timestamp:

2016-04-25T16:46:31Z (9 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

32573ff

Parents:

dc0d8b52

Message:

TLS for dynamically linked executables and initially loaded DSOs (but must not call dlopen or there will be trouble).

Location:

uspace/lib/c/generic/rtld

Files:

• module.c (modified) (6 diffs)
• rtld.c (modified) (7 diffs)

uspace/lib/c/generic/rtld/module.c

@@ -37 +37 @@
 #include <adt/list.h>
 #include <elf/elf_load.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <loader/pcb.h>
@@ -129 +130 @@
         int rc;
         
-        m = malloc(sizeof(module_t));
-        if (!m) {
+        m = calloc(1, sizeof(module_t));
+        if (m == NULL) {
                 printf("malloc failed\n");
                 exit(1);
@@ -136 +137 @@
 
         m->rtld = rtld;
+        m->id = rtld_get_next_id(rtld);
 
         if (str_size(name) > NAME_BUF_SIZE - 2) {
@@ -174 +176 @@
         /* Insert into the list of loaded modules */
         list_append(&m->modules_link, &rtld->modules);
+
+        /* Copy TLS info */
+        m->tdata = info.tls.tdata;
+        m->tdata_size = info.tls.tdata_size;
+        m->tbss_size = info.tls.tbss_size;
+
+        printf("tdata at %p size %zu, tbss size %zu\n",
+            m->tdata, m->tdata_size, m->tbss_size);
 
         return m;
@@ -236 +246 @@
 }
 
+/** Find module structure by ID. */
+module_t *module_by_id(rtld_t *rtld, unsigned long id)
+{
+        list_foreach(rtld->modules, modules_link, module_t, m) {
+                if (m->id == id)
+                        return m;
+        }
+
+        return NULL;
+}
+
 /** Process relocations in modules.
  *
@@ -253 +274 @@
 }
 
+void modules_process_tls(rtld_t *rtld)
+{
+        list_foreach(rtld->modules, modules_link, module_t, m) {
+                m->ioffs = rtld->tls_size;
+                rtld->tls_size += m->tdata_size + m->tbss_size;
+        }
+}
+
 /** Clear BFS tags of all modules.
  */

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

@@ -43 +43 @@
 rtld_t *runtime_env;
 static rtld_t rt_env_static;
-static module_t prog_mod;
 
 /** Initialize the runtime linker for use in a statically-linked executable. */
@@ -62 +61 @@
 {
         rtld_t *env;
+        module_t *prog;
 
         DPRINTF("Load dynamically linked program.\n");
@@ -70 +70 @@
                 return ENOMEM;
 
+        env->next_id = 1;
+
+        prog = calloc(1, sizeof(module_t));
+        if (prog == NULL) {
+                free(env);
+                return ENOMEM;
+        }
+
         /*
          * First we need to process dynamic sections of the executable
@@ -76 +84 @@
 
         DPRINTF("Parse program .dynamic section at %p\n", p_info->dynamic);
-        dynamic_parse(p_info->dynamic, 0, &prog_mod.dyn);
-        prog_mod.bias = 0;
-        prog_mod.dyn.soname = "[program]";
-        prog_mod.rtld = env;
+        dynamic_parse(p_info->dynamic, 0, &prog->dyn);
+        prog->bias = 0;
+        prog->dyn.soname = "[program]";
+        prog->rtld = env;
+        prog->id = rtld_get_next_id(env);
+
+        prog->tdata = p_info->tls.tdata;
+        prog->tdata_size = p_info->tls.tdata_size;
+        prog->tbss_size = p_info->tls.tbss_size;
+
+        printf("prog tdata at %p size %zu, tbss size %zu\n",
+            prog->tdata, prog->tdata_size, prog->tbss_size);
 
         /* Initialize list of loaded modules */
         list_initialize(&env->modules);
-        list_append(&prog_mod.modules_link, &env->modules);
+        list_append(&prog->modules_link, &env->modules);
 
         /* Pointer to program module. Used as root of the module graph. */
-        env->program = &prog_mod;
+        env->program = prog;
 
         /* Work around non-existent memory space allocation. */
@@ -96 +112 @@
 
         DPRINTF("Load all program dependencies\n");
-        module_load_deps(&prog_mod);
+        module_load_deps(prog);
 
         /*
@@ -104 +120 @@
         /* Process relocations in all modules */
         DPRINTF("Relocate all modules\n");
-        modules_process_relocs(env, &prog_mod);
+        modules_process_relocs(env, prog);
+
+        modules_process_tls(env);
 
         *rre = env;
@@ -110 +128 @@
 }
 
+/** Create TLS (Thread Local Storage) data structures.
+ *
+ * @return Pointer to TCB.
+ */
+tcb_t *rtld_tls_make(rtld_t *rtld)
+{
+        void *data;
+        tcb_t *tcb;
+        size_t offset;
+
+        tcb = tls_alloc_arch(&data, rtld->tls_size);
+        if (tcb == NULL)
+                return NULL;
+
+        /*
+         * Copy thread local data from the modules' initialization images.
+         * Zero out thread-local uninitialized data.
+         */
+
+        offset = 0;
+        list_foreach(rtld->modules, modules_link, module_t, m) {
+                memcpy(data + offset, m->tdata, m->tdata_size);
+                offset += m->tdata_size;
+                memset(data + offset, 0, m->tbss_size);
+                offset += m->tbss_size;
+        }
+
+        return tcb;
+}
+
+unsigned long rtld_get_next_id(rtld_t *rtld)
+{
+        return rtld->next_id++;
+}
+
+void *rtld_tls_get_addr(rtld_t *rtld, void *tls, unsigned long mod_id,
+    unsigned long offset)
+{
+        module_t *m;
+
+        m = module_by_id(rtld, mod_id);
+        assert(m != NULL);
+
+        return tls + m->ioffs + offset;
+}
+
+
 /** @}
  */