fix merge

1 files changed, 15 insertions, 0 deletions

diff --git a/hurd/hurd/threadvar.h b/hurd/hurd/threadvar.h
index c61e3bb9d9..414e452db5 100644
--- a/hurd/hurd/threadvar.h
+++ b/hurd/hurd/threadvar.h
@@ -22,6 +22,21 @@
 #include <features.h>
 #include <tls.h>
 
+/* The per-thread variables are found by ANDing this mask
+   with the value of the stack pointer and then adding this offset.
+
+   In the multi-threaded case, cthreads initialization sets
+   __hurd_threadvar_stack_mask to ~(cthread_stack_size - 1), a mask which
+   finds the base of the fixed-size cthreads stack; and
+   __hurd_threadvar_stack_offset to a small offset that skips the data
+   cthreads itself maintains at the base of each thread's stack.
+
+   In the single-threaded or libpthread case, __hurd_threadvar_stack_mask is
+   zero, so the stack pointer is ignored. */
+
+extern unsigned long int __hurd_threadvar_stack_mask;
+extern unsigned long int __hurd_threadvar_stack_offset;
+
 /* The variables __hurd_sigthread_stack_base and
    __hurd_sigthread_stack_end define the bounds of the stack used by the
    signal thread, so that thread can always be specifically identified.  */