Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

[deliverable/linux.git] / lib / Kconfig.debug

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e2a236a7341fe1b81f4d2dbfe525ab146ff6e691..ee1ac1cc082c10318c2ae6f88890124e9c9c934e 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1886,3 +1886,42 @@ source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"
 
+config ARCH_HAS_DEVMEM_IS_ALLOWED
+       bool
+
+config STRICT_DEVMEM
+       bool "Filter access to /dev/mem"
+       depends on MMU
+       depends on ARCH_HAS_DEVMEM_IS_ALLOWED
+       default y if TILE || PPC
+       ---help---
+         If this option is disabled, you allow userspace (root) access to all
+         of memory, including kernel and userspace memory. Accidental
+         access to this is obviously disastrous, but specific access can
+         be used by people debugging the kernel. Note that with PAT support
+         enabled, even in this case there are restrictions on /dev/mem
+         use due to the cache aliasing requirements.
+
+         If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
+         file 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.
+
+         If in doubt, say Y.
+
+config IO_STRICT_DEVMEM
+       bool "Filter I/O access to /dev/mem"
+       depends on STRICT_DEVMEM
+       default STRICT_DEVMEM
+       ---help---
+         If this option is disabled, you allow userspace (root) access to all
+         io-memory regardless of whether a driver is actively using that
+         range.  Accidental access to this is obviously disastrous, but
+         specific access can be used by people debugging kernel drivers.
+
+         If this option is switched on, the /dev/mem file only allows
+         userspace access to *idle* io-memory ranges (see /proc/iomem) This
+         may break traditional users of /dev/mem (dosemu, legacy X, etc...)
+         if the driver using a given range cannot be disabled.
+
+         If in doubt, say Y.