x86: introduce /dev/mem restrictions with a config option

[linux-2.6-omap-h63xx.git] / arch / x86 / Kconfig.debug

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 610aaecc19f820013ecfb9564f6c7b9762fdb82c..0c1890c41279735b68931f2aefe0b54be06638d8 100644 (file)
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,6 +5,18 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
+config NONPROMISC_DEVMEM
+       bool "Disable promiscuous /dev/mem"
+       default y
+       help
+         The /dev/mem file by default only allows userspace access to PCI
+         space and the BIOS code and data regions. This is sufficient for
+         dosemu and X and all common users of /dev/mem. With this config
+         option, you allow userspace access to all of memory, including
+         kernel and userspace memory. Accidental access to this is
+         obviously disasterous, but specific access can be used by people
+         debugging the kernel.
+
 config EARLY_PRINTK
        bool "Early printk" if EMBEDDED
        default y