diff options
| -rw-r--r-- | drivers/char/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/char/mem.c | 17 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 3bb6fa3930b..ddbed25c7af 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -6,6 +6,19 @@ menu "Character devices" source "drivers/tty/Kconfig" +config DEVMEM + bool "Memory device driver" + default y + help + The memory driver provides two character devices, mem and kmem, which + provide access to the system's memory. The mem device is a view of + physical memory, and each byte in the device corresponds to the + matching physical address. The kmem device is the same as mem, but + the addresses correspond to the kernel's virtual address space rather + than physical memory. These devices are standard parts of a Linux + system and most users should say Y here. You might say N if very + security conscience or memory is tight. + config DEVKMEM bool "/dev/kmem virtual device support" default y diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 1ccbe9482fa..38d3069b7f0 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -60,6 +60,7 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) } #endif +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) #ifdef CONFIG_STRICT_DEVMEM static inline int range_is_allowed(unsigned long pfn, unsigned long size) { @@ -85,7 +86,9 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size) return 1; } #endif +#endif +#ifdef CONFIG_DEVMEM void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr) { } @@ -212,6 +215,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf, *ppos += written; return written; } +#endif /* CONFIG_DEVMEM */ + +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) int __weak phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, unsigned long size, pgprot_t *vma_prot) @@ -333,6 +339,7 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) } return 0; } +#endif /* CONFIG_DEVMEM */ #ifdef CONFIG_DEVKMEM static int mmap_kmem(struct file *file, struct vm_area_struct *vma) @@ -727,6 +734,8 @@ static loff_t null_lseek(struct file *file, loff_t offset, int orig) return file->f_pos = 0; } +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT) + /* * The memory devices use the full 32/64 bits of the offset, and so we cannot * check against negative addresses: they are ok. The return value is weird, @@ -760,10 +769,14 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig) return ret; } +#endif + +#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT) static int open_port(struct inode *inode, struct file *filp) { return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; } +#endif #define zero_lseek null_lseek #define full_lseek null_lseek @@ -774,6 +787,7 @@ static int open_port(struct inode *inode, struct file *filp) #define open_kmem open_mem #define open_oldmem open_mem +#ifdef CONFIG_DEVMEM static const struct file_operations mem_fops = { .llseek = memory_lseek, .read = read_mem, @@ -782,6 +796,7 @@ static const struct file_operations mem_fops = { .open = open_mem, .get_unmapped_area = get_unmapped_area_mem, }; +#endif #ifdef CONFIG_DEVKMEM static const struct file_operations kmem_fops = { @@ -851,7 +866,9 @@ static const struct memdev { const struct file_operations *fops; struct backing_dev_info *dev_info; } devlist[] = { +#ifdef CONFIG_DEVMEM [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi }, +#endif #ifdef CONFIG_DEVKMEM [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi }, #endif |