1 files changed, 47 insertions, 1 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e2a236a7341f..f75a33f29f6e 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -580,6 +580,14 @@ config DEBUG_VM_RB
 
 	  If unsure, say N.
 
+config DEBUG_VM_PGFLAGS
+	bool "Debug page-flags operations"
+	depends on DEBUG_VM
+	help
+	  Enables extra validation on page flags operations.
+
+	  If unsure, say N.
+
 config DEBUG_VIRTUAL
 	bool "Debug VM translations"
 	depends on DEBUG_KERNEL && X86
@@ -1589,7 +1597,6 @@ config FAULT_INJECTION_STACKTRACE_FILTER
 
 config LATENCYTOP
 	bool "Latency measuring infrastructure"
-	depends on HAVE_LATENCYTOP_SUPPORT
 	depends on DEBUG_KERNEL
 	depends on STACKTRACE_SUPPORT
 	depends on PROC_FS
@@ -1886,3 +1893,42 @@ 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.