From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Tue, 5 Dec 2017 08:14:20 +0000 (-0800)
Subject: rtld - Fix ifunc relocations
X-Git-Tag: v5.3.0~728
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/adb072584ea04a3358cc137eb6714046f3d31266

rtld - Fix ifunc relocations

* ifunc relocations had a bug that caused an immediate seg-fault.
  Apparently this type of relocation is not used very much, we've
  never encountered it before.  But the qemu port uses it.

* Fix the bug.  Basically missing lockstate and the top level in
  rtld was expected to hold the bind lock.
---

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 16d5ba7111..1680ab1ef0 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -674,10 +674,19 @@ resident_skip2:
     map_stacks_exec(NULL);
 
     dbg("resolving ifuncs");
-    if (resolve_objects_ifunc(obj_main,
-      ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
-      NULL) == -1)
-	die();
+    {
+	    RtldLockState lockstate;
+
+	    wlock_acquire(rtld_bind_lock, &lockstate);
+	    if (resolve_objects_ifunc(
+		    obj_main,
+		    (ld_bind_now != NULL && *ld_bind_now != '\0'),
+		    SYMLOOK_EARLY,
+		    &lockstate) == -1) {
+		    die();
+	    }
+	    lock_release(rtld_bind_lock, &lockstate);
+    }
 
     /*
      * Do NOT call the initlist here, give libc a chance to set up