Merge tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

[cascardo/linux.git] / arch / x86 / Kconfig

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 666ac66..bea3a01 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -992,6 +992,24 @@ config X86_ESPFIX64
        def_bool y
        depends on X86_16BIT && X86_64
 
+config X86_VSYSCALL_EMULATION
+       bool "Enable vsyscall emulation" if EXPERT
+       default y
+       depends on X86_64
+       ---help---
+        This enables emulation of the legacy vsyscall page.  Disabling
+        it is roughly equivalent to booting with vsyscall=none, except
+        that it will also disable the helpful warning if a program
+        tries to use a vsyscall.  With this option set to N, offending
+        programs will just segfault, citing addresses of the form
+        0xffffffffff600?00.
+
+        This option is required by many programs built before 2013, and
+        care should be used even with newer programs if set to N.
+
+        Disabling this option saves about 7K of kernel size and
+        possibly 4K of additional runtime pagetable memory.
+
 config TOSHIBA
        tristate "Toshiba Laptop support"
        depends on X86_32