Changeset d2bb25e7 in mainline for uspace/lib/c/generic/rtld/rtld.c

Timestamp:

2016-05-17T22:51:37Z (9 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

9c07c3d

Parents:

e2f26002

Message:

Use DTVs. symbol_get_addr() should not implicitly read current thread pointer.

File:

• uspace/lib/c/generic/rtld/rtld.c (modified) (6 diffs)

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

@@ -143 +143 @@
         tcb_t *tcb;
         size_t offset;
+        void **dtv;
+        size_t nmods;
+        size_t i;
 
         tcb = tls_alloc_arch(&data, rtld->tls_size);
@@ -148 +151 @@
                 return NULL;
 
-        /*
-         * Copy thread local data from the modules' initialization images.
-         * Zero out thread-local uninitialized data.
+        /** Allocate dynamic thread vector */
+        nmods = list_count(&rtld->imodules);
+        dtv = malloc((nmods + 1) * sizeof(void *));
+        if (dtv == NULL) {
+                tls_free(tcb);
+                return NULL;
+        }
+
+        /*
+         * We define generation number to be equal to vector length.
+         * We start with a vector covering the initially loaded modules.
+         */
+        DTV_GN(dtv) = nmods;
+
+        /*
+         * Copy thread local data from the initialization images of initial
+         * modules. Zero out thread-local uninitialized data.
          */
 
@@ -157 +174 @@
          * Ascending addresses
          */
-        offset = 0;
+        offset = 0; i = 1;
         list_foreach(rtld->imodules, imodules_link, module_t, m) {
+                assert(i == m->id);
                 assert(offset + m->tdata_size + m->tbss_size <= rtld->tls_size);
+                dtv[i++] = data + offset;
                 memcpy(data + offset, m->tdata, m->tdata_size);
                 offset += m->tdata_size;
@@ -169 +188 @@
          * Descending addresses
          */
-        offset = 0;
+        offset = 0; i = 1;
         list_foreach(rtld->imodules, imodules_link, module_t, m) {
+                assert(i == m->id);
                 assert(offset + m->tdata_size + m->tbss_size <= rtld->tls_size);
                 offset += m->tbss_size;
@@ -176 +196 @@
                 offset += m->tdata_size;
                 memcpy(data + rtld->tls_size - offset, m->tdata, m->tdata_size);
+                dtv[i++] = data + rtld->tls_size - offset;
         }
 #endif
 
+        tcb->dtv = dtv;
         return tcb;
 }
@@ -187 +209 @@
 }
 
-void *rtld_tls_get_addr(rtld_t *rtld, unsigned long mod_id,
+/** Get address of thread-local variable.
+ *
+ * @param rtld RTLD instance
+ * @param tcb TCB of the thread whose instance to return
+ * @param mod_id Module ID
+ * @param offset Offset within TLS block of the module
+ *
+ * @return Address of thread-local variable
+ */
+void *rtld_tls_get_addr(rtld_t *rtld, tcb_t *tcb, unsigned long mod_id,
     unsigned long offset)
 {
-        module_t *m;
-        uint8_t *tls;
-
-        m = module_by_id(rtld, mod_id);
-        assert(m != NULL);
-
-        if (!link_used(&m->imodules_link)) {
-                printf("module '%s' is not initial. aborting.\n",
-                    m->dyn.soname);
+        if (DTV_GN(tcb->dtv) < mod_id || tcb->dtv[mod_id] == NULL) {
+                printf("Module is not initial. aborting.\n");
                 abort();
         }
 
-        tls = tls_get();
-        return tls + m->ioffs + offset;
-}
-
+        return (uint8_t *)(tcb->dtv[mod_id]) + offset;
+}
 
 /** @}