diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ae36bfa814e5b389d706b9cc3fa1d879f16abe8b..f0cf5d9907947c6536ecf07ea5aa224db10623f4 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,10 +5,11 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config NONPROMISC_DEVMEM
-	bool "Filter access to /dev/mem"
+config PROMISC_DEVMEM
+	bool "Allow unlimited access to /dev/mem"
+	default y
 	help
-	  If this option is left off, you allow userspace access to all
+	  If this option is left on, 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.
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index d4585077977a0bd1c6c7234b09051d671851a6aa..c34dc483839c3f5c29d72f11cfd779c1f9e34977 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -373,8 +373,8 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 	return vma_prot;
 }
 
-#ifdef CONFIG_NONPROMISC_DEVMEM
-/* This check is done in drivers/char/mem.c in case of NONPROMISC_DEVMEM*/
+#ifndef CONFIG_PROMISC_DEVMEM
+/* This check is done in drivers/char/mem.c in case of !PROMISC_DEVMEM*/
 static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 {
 	return 1;
@@ -398,7 +398,7 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 	}
 	return 1;
 }
-#endif /* CONFIG_NONPROMISC_DEVMEM */
+#endif /* CONFIG_PROMISC_DEVMEM */
 
 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 				unsigned long size, pgprot_t *vma_prot)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 070e22e8ea9efb43a180149caa5a47d70faf471f..de05775bd687c52d8de12087fbe7ef260332ef4c 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -80,7 +80,7 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
 }
 #endif
 
-#ifdef CONFIG_NONPROMISC_DEVMEM
+#ifndef CONFIG_PROMISC_DEVMEM
 static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 {
 	u64 from = ((u64)pfn) << PAGE_SHIFT;