[S390] noexec protection

[linux-2.6-omap-h63xx.git] / arch / s390 / Kconfig

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 12272361c018c41b1b34c2f33a526e80646cc8b1..5c7e981c115b1c427d15236910b8166972ee0021 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -134,6 +134,31 @@ config AUDIT_ARCH
        bool
        default y
 
+config S390_SWITCH_AMODE
+       bool "Switch kernel/user addressing modes"
+       help
+         This option allows to switch the addressing modes of kernel and user
+         space. The kernel parameter switch_amode=on will enable this feature,
+         default is disabled. Enabling this (via kernel parameter) on machines
+         earlier than IBM System z9-109 EC/BC will reduce system performance.
+
+         Note that this option will also be selected by selecting the execute
+         protection option below. Enabling the execute protection via the
+         noexec kernel parameter will also switch the addressing modes,
+         independent of the switch_amode kernel parameter.
+
+
+config S390_EXEC_PROTECT
+       bool "Data execute protection"
+       select S390_SWITCH_AMODE
+       help
+         This option allows to enable a buffer overflow protection for user
+         space programs and it also selects the addressing mode option above.
+         The kernel parameter noexec=on will enable this feature and also
+         switch the addressing modes, default is disabled. Enabling this (via
+         kernel parameter) on machines earlier than IBM System z9-109 EC/BC
+         will reduce system performance.
+
 comment "Code generation options"
 
 choice