Changes in uspace/lib/c/generic/rtld/module.c [ffccdff0:32254d6] in mainline

File:

• uspace/lib/c/generic/rtld/module.c (modified) (5 diffs)

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

@@ -1 +1 @@
 /*
- * Copyright (c) 2008 Jiri Svoboda
+ * Copyright (c) 2024 Jiri Svoboda
  * All rights reserved.
  *
@@ -55 +55 @@
 #include "../private/libc.h"
 
-/** Create module for static executable.
- *
+/** Create the "entrypoint" module, of the program executable
+ *
+ * @param p_info Program ELF file info
  * @param rtld Run-time dynamic linker
  * @param rmodule Place to store pointer to new module or @c NULL
  * @return EOK on success, ENOMEM if out of memory
  */
-errno_t module_create_static_exec(rtld_t *rtld, module_t **rmodule)
+errno_t module_create_entrypoint(elf_finfo_t *p_info, rtld_t *rtld, module_t **rmodule)
 {
         module_t *module;
+        bool is_dynamic = p_info->dynamic != NULL;
+        DPRINTF("module_create_entrypoint\n");
 
         module = calloc(1, sizeof(module_t));
-        if (module == NULL) {
-                DPRINTF("malloc failed\n");
+        if (module == NULL)
                 return ENOMEM;
-        }
-
+
+        uintptr_t bias = elf_get_bias(p_info->base);
+
+        /*
+         * First we need to process dynamic sections of the executable
+         * program and insert it into the module graph.
+         */
+        if (is_dynamic) {
+                DPRINTF("Parse program .dynamic section at %p\n", p_info->dynamic);
+                dynamic_parse(p_info->dynamic, bias, &module->dyn);
+        } else {
+                DPRINTF("Executable is not dynamically linked\n");
+        }
+
+        module->bias = bias;
         module->id = rtld_get_next_id(rtld);
         module->dyn.soname = "[program]";
@@ -76 +91 @@
         module->rtld = rtld;
         module->exec = true;
-        module->local = true;
-
-        const elf_segment_header_t *tls =
-            elf_get_phdr(__progsymbols.elfstart, PT_TLS);
-
-        if (tls) {
-                uintptr_t bias = elf_get_bias(__progsymbols.elfstart);
-                module->tdata = (void *) (tls->p_vaddr + bias);
-                module->tdata_size = tls->p_filesz;
-                module->tbss_size = tls->p_memsz - tls->p_filesz;
-                module->tls_align = tls->p_align;
-        } else {
-                module->tdata = NULL;
-                module->tdata_size = 0;
-                module->tbss_size = 0;
-                module->tls_align = 1;
-        }
+        module->local = !is_dynamic;
+
+        module->tdata = p_info->tls.tdata;
+        module->tdata_size = p_info->tls.tdata_size;
+        module->tbss_size = p_info->tls.tbss_size;
+        module->tls_align = p_info->tls.tls_align;
+
+        DPRINTF("prog tdata at %p size %zu, tbss size %zu\n",
+        module->tdata, module->tdata_size, module->tbss_size);
 
         list_append(&module->modules_link, &rtld->modules);
@@ -343 +350 @@
 {
         list_foreach(rtld->modules, modules_link, module_t, m) {
-                /* Skip rtld module, since it has already been processed */
-                if (m != &rtld->rtld) {
+                /*
+                 * Skip rtld module, since it has already been processed.
+                 * Skip start / main program -- leave it for later
+                 */
+                if (m != &rtld->rtld && m != start) {
                         module_process_relocs(m);
                 }
         }
+
+        /*
+         * Now that shared libraries have been processed and their variables
+         * are thus initialized, we can process the main program,
+         * which may contain COPY relocations that copy value from shared
+         * library variables to instances of those variables defined
+         * in the main program.
+         */
+        module_process_relocs(start);
 }
 
@@ -386 +405 @@
          * be correct, "zero" offset (i.e. the total size) must be aligned
          * to the strictest alignment present.
-         * Note that the padding is actually in front of the TLS data,
-         * not after it.
          */
         rtld->tls_size = ALIGN_UP(rtld->tls_size, rtld->tls_align);
 
-        /* Space for the TCB. */
+        /*
+         * Space for the TCB.
+         * Later, the TLS zero offset is equal to the pointer to tcb_t, so
+         * adding the sizeof(tcb_t) block AFTER we calculated the alignment
+         * of the remainder above is correct.
+         */
         rtld->tls_size += sizeof(tcb_t);
 #endif