diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/char/mem.c | 12 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 40728491f37b..aca628e0d4d4 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -16,6 +16,15 @@ config DEVMEM memory. When in doubt, say "Y". +config DEVMEM_BOOTPARAM + bool "mem.devmem boot parameter" + depends on DEVMEM + default n + help + This option adds a 'mem.devmem' kernel parameter which activates + the /dev/mem device when enabled. + When in doubt, say "N". + config DEVKMEM bool "/dev/kmem virtual device support" # On arm64, VMALLOC_START < PAGE_OFFSET, which confuses kmem read/write diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 7b4e4de778e4..7fa6366a1b92 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -10,6 +10,7 @@ */ #include <linux/mm.h> +#include <linux/moduleparam.h> #include <linux/miscdevice.h> #include <linux/slab.h> #include <linux/vmalloc.h> @@ -36,6 +37,7 @@ # include <linux/efi.h> #endif +#define DEVMEM_MINOR 1 #define DEVPORT_MINOR 4 static inline unsigned long size_inside_page(unsigned long start, @@ -913,6 +915,12 @@ static char *mem_devnode(struct device *dev, umode_t *mode) return NULL; } +#ifdef CONFIG_DEVMEM_BOOTPARAM +static bool devmem; +module_param(devmem, bool, 0444); +MODULE_PARM_DESC(devmem, "kernel parameter to activate /dev/mem"); +#endif + static struct class *mem_class; static int __init chr_dev_init(void) @@ -931,6 +939,10 @@ static int __init chr_dev_init(void) if (!devlist[minor].name) continue; +#ifdef CONFIG_DEVMEM_BOOTPARAM + if (minor == DEVMEM_MINOR && !devmem) + continue; +#endif /* * Create /dev/port? */ |