[PATCH V2 03/19] vdso: Add CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT

[Adrian Hunter]

Add CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT in preparation to add
multiplication overflow protection to the VDSO time getter functions.

Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 lib/vdso/Kconfig | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index d883ac299508..c46c2300517c 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,4 +30,11 @@ config GENERIC_VDSO_TIME_NS
 	  Selected by architectures which support time namespaces in the
 	  VDSO
 
+config GENERIC_VDSO_OVERFLOW_PROTECT
+	bool
+	help
+	  Select to add multiplication overflow protection to the VDSO
+	  time getter functions for the price of an extra conditional
+	  in the hotpath.
+
 endif
-- 
2.34.1