2 files changed, 19 insertions, 0 deletions

diff --git a/arch/i386/xen/setup.c b/arch/i386/xen/setup.c
index 2fe6eac510f0..f84e77226646 100644
--- a/arch/i386/xen/setup.c
+++ b/arch/i386/xen/setup.c
@@ -19,6 +19,7 @@
 #include <xen/features.h>
 
 #include "xen-ops.h"
+#include "vdso.h"
 
 /* These are code, but not functions.  Defined in entry.S */
 extern const char xen_hypervisor_callback[];
@@ -55,6 +56,18 @@ static void xen_idle(void)
         }
 }
 
+/*
+ * Set the bit indicating "nosegneg" library variants should be used.
+ */
+static void fiddle_vdso(void)
+{
+        extern u32 VDSO_NOTE_MASK; /* See ../kernel/vsyscall-note.S.  */
+        extern char vsyscall_int80_start;
+        u32 *mask = (u32 *) ((unsigned long) &VDSO_NOTE_MASK - VDSO_PRELINK +
+                             &vsyscall_int80_start);
+        *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
+}
+
 void __init xen_arch_setup(void)
 {
         struct physdev_set_iopl set_iopl;
@@ -93,4 +106,6 @@ void __init xen_arch_setup(void)
 #endif
 
         paravirt_disable_iospace();
+
+        fiddle_vdso();
 }
diff --git a/arch/i386/xen/vdso.h b/arch/i386/xen/vdso.h
new file mode 100644
index 000000000000..861fedfe5230
--- /dev/null
+++ b/arch/i386/xen/vdso.h
@@ -0,0 +1,4 @@
+/* Bit used for the pseudo-hwcap for non-negative segments.  We use
+   bit 1 to avoid bugs in some versions of glibc when bit 0 is
+   used; the choice is otherwise arbitrary. */
+#define VDSO_NOTE_NONEGSEG_BIT  1