diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/char/mem.c | 22 |
2 files changed, 17 insertions, 14 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index efefd12a0f7b..a4af8221751e 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -6,6 +6,15 @@ menu "Character devices" source "drivers/tty/Kconfig" +config DEVMEM + bool "/dev/mem virtual device support" + default y + help + Say Y here if you want to support the /dev/mem device. + The /dev/mem device is used to access areas of physical + memory. + When in doubt, say "Y". + config DEVKMEM bool "/dev/kmem virtual device support" default y diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 4c58333b4257..080273287c48 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -28,7 +28,7 @@ #include <linux/io.h> #include <linux/aio.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #ifdef CONFIG_IA64 # include <linux/efi.h> @@ -341,7 +341,6 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) return 0; } -#ifdef CONFIG_DEVKMEM static int mmap_kmem(struct file *file, struct vm_area_struct *vma) { unsigned long pfn; @@ -362,9 +361,7 @@ static int mmap_kmem(struct file *file, struct vm_area_struct *vma) vma->vm_pgoff = pfn; return mmap_mem(file, vma); } -#endif -#ifdef CONFIG_DEVKMEM /* * This function reads the *virtual* memory as seen by the kernel. */ @@ -544,9 +541,7 @@ static ssize_t write_kmem(struct file *file, const char __user *buf, *ppos = p; return virtr + wrote ? : err; } -#endif -#ifdef CONFIG_DEVPORT static ssize_t read_port(struct file *file, char __user *buf, size_t count, loff_t *ppos) { @@ -575,6 +570,7 @@ static ssize_t write_port(struct file *file, const char __user *buf, return -EFAULT; while (count-- > 0 && i < 65536) { char c; + if (__get_user(c, tmp)) { if (tmp > buf) break; @@ -587,7 +583,6 @@ static ssize_t write_port(struct file *file, const char __user *buf, *ppos = i; return tmp-buf; } -#endif static ssize_t read_null(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -631,6 +626,7 @@ static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) while (iov_iter_count(iter)) { size_t chunk = iov_iter_count(iter), n; + if (chunk > PAGE_SIZE) chunk = PAGE_SIZE; /* Just for latency reasons */ n = iov_iter_zero(chunk, iter); @@ -715,7 +711,7 @@ static int open_port(struct inode *inode, struct file *filp) #define open_mem open_port #define open_kmem open_mem -static const struct file_operations mem_fops = { +static const struct file_operations __maybe_unused mem_fops = { .llseek = memory_lseek, .read = read_mem, .write = write_mem, @@ -724,8 +720,7 @@ static const struct file_operations mem_fops = { .get_unmapped_area = get_unmapped_area_mem, }; -#ifdef CONFIG_DEVKMEM -static const struct file_operations kmem_fops = { +static const struct file_operations __maybe_unused kmem_fops = { .llseek = memory_lseek, .read = read_kmem, .write = write_kmem, @@ -733,7 +728,6 @@ static const struct file_operations kmem_fops = { .open = open_kmem, .get_unmapped_area = get_unmapped_area_mem, }; -#endif static const struct file_operations null_fops = { .llseek = null_lseek, @@ -744,14 +738,12 @@ static const struct file_operations null_fops = { .splice_write = splice_write_null, }; -#ifdef CONFIG_DEVPORT -static const struct file_operations port_fops = { +static const struct file_operations __maybe_unused port_fops = { .llseek = memory_lseek, .read = read_port, .write = write_port, .open = open_port, }; -#endif static const struct file_operations zero_fops = { .llseek = zero_lseek, @@ -785,7 +777,9 @@ 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 |