Only process clone results in the parent thread

Fixes BZ#423963

diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index 5ae4e66132d513f6f14e4e85e66ef06b1e8e93e5..c59d8ee26b3f82d15a6e2b76f7ce99d26e15a8b1 100644 (file)
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -940,7 +940,7 @@ PRE(sys_clone)
          ("Valgrind does not support general clone().");
    }
 
-   if (SUCCESS) {
+   if (SUCCESS && RES != 0) {
       if (ARG_FLAGS & (VKI_CLONE_PARENT_SETTID | VKI_CLONE_PIDFD))
          POST_MEM_WRITE(ARG3, sizeof(Int));
       if (ARG_FLAGS & (VKI_CLONE_CHILD_SETTID | VKI_CLONE_CHILD_CLEARTID))