diff options
Diffstat (limited to 'drivers/char/mem.c')
| -rw-r--r-- | drivers/char/mem.c | 86 |
1 files changed, 40 insertions, 46 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 4c58333b4257..297110c12635 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> @@ -287,13 +287,24 @@ static unsigned long get_unmapped_area_mem(struct file *file, return pgoff << PAGE_SHIFT; } +/* permit direct mmap, for read, write or exec */ +static unsigned memory_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_DIRECT | + NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; +} + +static unsigned zero_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_COPY; +} + /* can't do an in-place private mapping if there's no MMU */ static inline int private_mapping_ok(struct vm_area_struct *vma) { return vma->vm_flags & VM_MAYSHARE; } #else -#define get_unmapped_area_mem NULL static inline int private_mapping_ok(struct vm_area_struct *vma) { @@ -341,7 +352,6 @@ 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 +372,7 @@ 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 +552,7 @@ 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 +581,7 @@ 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 +594,6 @@ 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 +637,7 @@ 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); @@ -715,25 +722,29 @@ 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, .mmap = mmap_mem, .open = open_mem, +#ifndef CONFIG_MMU .get_unmapped_area = get_unmapped_area_mem, + .mmap_capabilities = memory_mmap_capabilities, +#endif }; -#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, .mmap = mmap_kmem, .open = open_kmem, +#ifndef CONFIG_MMU .get_unmapped_area = get_unmapped_area_mem, -}; + .mmap_capabilities = memory_mmap_capabilities, #endif +}; static const struct file_operations null_fops = { .llseek = null_lseek, @@ -744,14 +755,12 @@ 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, @@ -760,16 +769,9 @@ static const struct file_operations zero_fops = { .read_iter = read_iter_zero, .aio_write = aio_write_zero, .mmap = mmap_zero, -}; - -/* - * capabilities for /dev/zero - * - permits private mappings, "copies" are taken of the source of zeros - * - no writeback happens - */ -static struct backing_dev_info zero_bdi = { - .name = "char/mem", - .capabilities = BDI_CAP_MAP_COPY | BDI_CAP_NO_ACCT_AND_WRITEBACK, +#ifndef CONFIG_MMU + .mmap_capabilities = zero_mmap_capabilities, +#endif }; static const struct file_operations full_fops = { @@ -783,22 +785,24 @@ static const struct memdev { const char *name; umode_t mode; const struct file_operations *fops; - struct backing_dev_info *dev_info; + fmode_t fmode; } devlist[] = { - [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi }, +#ifdef CONFIG_DEVMEM + [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, +#endif #ifdef CONFIG_DEVKMEM - [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi }, + [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, #endif - [3] = { "null", 0666, &null_fops, NULL }, + [3] = { "null", 0666, &null_fops, 0 }, #ifdef CONFIG_DEVPORT - [4] = { "port", 0, &port_fops, NULL }, + [4] = { "port", 0, &port_fops, 0 }, #endif - [5] = { "zero", 0666, &zero_fops, &zero_bdi }, - [7] = { "full", 0666, &full_fops, NULL }, - [8] = { "random", 0666, &random_fops, NULL }, - [9] = { "urandom", 0666, &urandom_fops, NULL }, + [5] = { "zero", 0666, &zero_fops, 0 }, + [7] = { "full", 0666, &full_fops, 0 }, + [8] = { "random", 0666, &random_fops, 0 }, + [9] = { "urandom", 0666, &urandom_fops, 0 }, #ifdef CONFIG_PRINTK - [11] = { "kmsg", 0644, &kmsg_fops, NULL }, + [11] = { "kmsg", 0644, &kmsg_fops, 0 }, #endif }; @@ -816,12 +820,7 @@ static int memory_open(struct inode *inode, struct file *filp) return -ENXIO; filp->f_op = dev->fops; - if (dev->dev_info) - filp->f_mapping->backing_dev_info = dev->dev_info; - - /* Is /dev/mem or /dev/kmem ? */ - if (dev->dev_info == &directly_mappable_cdev_bdi) - filp->f_mode |= FMODE_UNSIGNED_OFFSET; + filp->f_mode |= dev->fmode; if (dev->fops->open) return dev->fops->open(inode, filp); @@ -846,11 +845,6 @@ static struct class *mem_class; static int __init chr_dev_init(void) { int minor; - int err; - - err = bdi_init(&zero_bdi); - if (err) - return err; if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) printk("unable to get major %d for memory devs\n", MEM_MAJOR); |