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-rw-r--r--arch/x86/Kconfig.debug9
-rw-r--r--arch/x86/configs/i386_defconfig2
-rw-r--r--arch/x86/configs/x86_64_defconfig2
-rw-r--r--arch/x86/mm/pat.c6
-rw-r--r--drivers/char/mem.c2
5 files changed, 11 insertions, 10 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index f0cf5d9..51c8214 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,14 +5,15 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug"
-config PROMISC_DEVMEM
- bool "Allow unlimited access to /dev/mem"
- default y
+config STRICT_DEVMEM
+ bool "Filter access to /dev/mem"
help
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.
+ 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, the /dev/mem file only allows
userspace access to PCI space and the BIOS code and data regions.
diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig
index 9bc34e2..4d73f53 100644
--- a/arch/x86/configs/i386_defconfig
+++ b/arch/x86/configs/i386_defconfig
@@ -2047,7 +2047,7 @@ CONFIG_PROVIDE_OHCI1394_DMA_INIT=y
# CONFIG_SAMPLES is not set
# CONFIG_KGDB is not set
CONFIG_HAVE_ARCH_KGDB=y
-# CONFIG_NONPROMISC_DEVMEM is not set
+# CONFIG_STRICT_DEVMEM is not set
CONFIG_EARLY_PRINTK=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_STACK_USAGE=y
diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
index ae5124e..a404524 100644
--- a/arch/x86/configs/x86_64_defconfig
+++ b/arch/x86/configs/x86_64_defconfig
@@ -2012,7 +2012,7 @@ CONFIG_PROVIDE_OHCI1394_DMA_INIT=y
# CONFIG_SAMPLES is not set
# CONFIG_KGDB is not set
CONFIG_HAVE_ARCH_KGDB=y
-# CONFIG_NONPROMISC_DEVMEM is not set
+# CONFIG_STRICT_DEVMEM is not set
CONFIG_EARLY_PRINTK=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_STACK_USAGE=y
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index c34dc48..6bb597f 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;
}
-#ifndef CONFIG_PROMISC_DEVMEM
-/* This check is done in drivers/char/mem.c in case of !PROMISC_DEVMEM*/
+#ifdef CONFIG_STRICT_DEVMEM
+/* This check is done in drivers/char/mem.c in case of STRICT_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_PROMISC_DEVMEM */
+#endif /* CONFIG_STRICT_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 de05775..b6772d6 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
-#ifndef CONFIG_PROMISC_DEVMEM
+#ifdef CONFIG_STRICT_DEVMEM
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
u64 from = ((u64)pfn) << PAGE_SHIFT;