Setting up TLS block for the main thread must be done after the

relocations are processed, since tls initialization section might be
itself subject for relocations. Only set up of the block is postponed,
the tls block offsets are allocated before relocation processing, since
TLS-related relocations may need offsets ready.

Reported by:	ale
PR:	threads/161344
Reviewed by:	kan
MFC after:	1 week

1 files changed, 14 insertions, 3 deletions

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 65eadb5..36102ba 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -495,8 +495,12 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
        exit (0);
     }
 
-    /* setup TLS for main thread */
-    dbg("initializing initial thread local storage");
+    /*
+     * Processing tls relocations requires having the tls offsets
+     * initialized.  Prepare offsets before starting initial
+     * relocation processing.
+     */
+    dbg("initializing initial thread local storage offsets");
     STAILQ_FOREACH(entry, &list_main, link) {
 	/*
 	 * Allocate all the initial objects out of the static TLS
@@ -504,7 +508,6 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
 	 */
 	allocate_tls_offset(entry->obj);
     }
-    allocate_initial_tls(obj_list);
 
     if (relocate_objects(obj_main,
       ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, NULL) == -1)
@@ -519,6 +522,14 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
        exit (0);
     }
 
+    /*
+     * Setup TLS for main thread.  This must be done after the
+     * relocations are processed, since tls initialization section
+     * might be the subject for relocations.
+     */
+    dbg("initializing initial thread local storage");
+    allocate_initial_tls(obj_list);
+
     dbg("initializing key program variables");
     set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
     set_program_var("environ", env);