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-rw-r--r--drivers/char/mem.c1002
1 files changed, 1002 insertions, 0 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
new file mode 100644
index 0000000..6431f69
--- /dev/null
+++ b/drivers/char/mem.c
@@ -0,0 +1,1002 @@
+/*
+ * linux/drivers/char/mem.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Added devfs support.
+ * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
+ * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mman.h>
+#include <linux/random.h>
+#include <linux/init.h>
+#include <linux/raw.h>
+#include <linux/tty.h>
+#include <linux/capability.h>
+#include <linux/ptrace.h>
+#include <linux/device.h>
+#include <linux/highmem.h>
+#include <linux/crash_dump.h>
+#include <linux/backing-dev.h>
+#include <linux/bootmem.h>
+#include <linux/splice.h>
+#include <linux/pfn.h>
+#include <linux/smp_lock.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_IA64
+# include <linux/efi.h>
+#endif
+
+/*
+ * Architectures vary in how they handle caching for addresses
+ * outside of main memory.
+ *
+ */
+static inline int uncached_access(struct file *file, unsigned long addr)
+{
+#if defined(CONFIG_IA64)
+ /*
+ * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
+ */
+ return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
+#elif defined(CONFIG_MIPS)
+ {
+ extern int __uncached_access(struct file *file,
+ unsigned long addr);
+
+ return __uncached_access(file, addr);
+ }
+#else
+ /*
+ * Accessing memory above the top the kernel knows about or through a file pointer
+ * that was marked O_SYNC will be done non-cached.
+ */
+ if (file->f_flags & O_SYNC)
+ return 1;
+ return addr >= __pa(high_memory);
+#endif
+}
+
+#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
+static inline int valid_phys_addr_range(unsigned long addr, size_t count)
+{
+ if (addr + count > __pa(high_memory))
+ return 0;
+
+ return 1;
+}
+
+static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
+{
+ return 1;
+}
+#endif
+
+#ifdef CONFIG_STRICT_DEVMEM
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ u64 from = ((u64)pfn) << PAGE_SHIFT;
+ u64 to = from + size;
+ u64 cursor = from;
+
+ while (cursor < to) {
+ if (!devmem_is_allowed(pfn)) {
+ printk(KERN_INFO
+ "Program %s tried to access /dev/mem between %Lx->%Lx.\n",
+ current->comm, from, to);
+ return 0;
+ }
+ cursor += PAGE_SIZE;
+ pfn++;
+ }
+ return 1;
+}
+#else
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ return 1;
+}
+#endif
+
+void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
+{
+}
+
+/*
+ * This funcion reads the *physical* memory. The f_pos points directly to the
+ * memory location.
+ */
+static ssize_t read_mem(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t read, sz;
+ char *ptr;
+
+ if (!valid_phys_addr_range(p, count))
+ return -EFAULT;
+ read = 0;
+#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
+ /* we don't have page 0 mapped on sparc and m68k.. */
+ if (p < PAGE_SIZE) {
+ sz = PAGE_SIZE - p;
+ if (sz > count)
+ sz = count;
+ if (sz > 0) {
+ if (clear_user(buf, sz))
+ return -EFAULT;
+ buf += sz;
+ p += sz;
+ count -= sz;
+ read += sz;
+ }
+ }
+#endif
+
+ while (count > 0) {
+ /*
+ * Handle first page in case it's not aligned
+ */
+ if (-p & (PAGE_SIZE - 1))
+ sz = -p & (PAGE_SIZE - 1);
+ else
+ sz = PAGE_SIZE;
+
+ sz = min_t(unsigned long, sz, count);
+
+ if (!range_is_allowed(p >> PAGE_SHIFT, count))
+ return -EPERM;
+
+ /*
+ * On ia64 if a page has been mapped somewhere as
+ * uncached, then it must also be accessed uncached
+ * by the kernel or data corruption may occur
+ */
+ ptr = xlate_dev_mem_ptr(p);
+ if (!ptr)
+ return -EFAULT;
+
+ if (copy_to_user(buf, ptr, sz)) {
+ unxlate_dev_mem_ptr(p, ptr);
+ return -EFAULT;
+ }
+
+ unxlate_dev_mem_ptr(p, ptr);
+
+ buf += sz;
+ p += sz;
+ count -= sz;
+ read += sz;
+ }
+
+ *ppos += read;
+ return read;
+}
+
+static ssize_t write_mem(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t written, sz;
+ unsigned long copied;
+ void *ptr;
+
+ if (!valid_phys_addr_range(p, count))
+ return -EFAULT;
+
+ written = 0;
+
+#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
+ /* we don't have page 0 mapped on sparc and m68k.. */
+ if (p < PAGE_SIZE) {
+ unsigned long sz = PAGE_SIZE - p;
+ if (sz > count)
+ sz = count;
+ /* Hmm. Do something? */
+ buf += sz;
+ p += sz;
+ count -= sz;
+ written += sz;
+ }
+#endif
+
+ while (count > 0) {
+ /*
+ * Handle first page in case it's not aligned
+ */
+ if (-p & (PAGE_SIZE - 1))
+ sz = -p & (PAGE_SIZE - 1);
+ else
+ sz = PAGE_SIZE;
+
+ sz = min_t(unsigned long, sz, count);
+
+ if (!range_is_allowed(p >> PAGE_SHIFT, sz))
+ return -EPERM;
+
+ /*
+ * On ia64 if a page has been mapped somewhere as
+ * uncached, then it must also be accessed uncached
+ * by the kernel or data corruption may occur
+ */
+ ptr = xlate_dev_mem_ptr(p);
+ if (!ptr) {
+ if (written)
+ break;
+ return -EFAULT;
+ }
+
+ copied = copy_from_user(ptr, buf, sz);
+ if (copied) {
+ written += sz - copied;
+ unxlate_dev_mem_ptr(p, ptr);
+ if (written)
+ break;
+ return -EFAULT;
+ }
+
+ unxlate_dev_mem_ptr(p, ptr);
+
+ buf += sz;
+ p += sz;
+ count -= sz;
+ written += sz;
+ }
+
+ *ppos += written;
+ return written;
+}
+
+int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
+ unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
+{
+ return 1;
+}
+
+#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
+static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+#ifdef pgprot_noncached
+ unsigned long offset = pfn << PAGE_SHIFT;
+
+ if (uncached_access(file, offset))
+ return pgprot_noncached(vma_prot);
+#endif
+ return vma_prot;
+}
+#endif
+
+#ifndef CONFIG_MMU
+static unsigned long get_unmapped_area_mem(struct file *file,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags)
+{
+ if (!valid_mmap_phys_addr_range(pgoff, len))
+ return (unsigned long) -EINVAL;
+ return pgoff << PAGE_SHIFT;
+}
+
+/* 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)
+{
+ return 1;
+}
+#endif
+
+void __attribute__((weak))
+map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+void __attribute__((weak))
+unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+static void mmap_mem_open(struct vm_area_struct *vma)
+{
+ map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static void mmap_mem_close(struct vm_area_struct *vma)
+{
+ unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static struct vm_operations_struct mmap_mem_ops = {
+ .open = mmap_mem_open,
+ .close = mmap_mem_close,
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+ .access = generic_access_phys
+#endif
+};
+
+static int mmap_mem(struct file * file, struct vm_area_struct * vma)
+{
+ size_t size = vma->vm_end - vma->vm_start;
+
+ if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
+ return -EINVAL;
+
+ if (!private_mapping_ok(vma))
+ return -ENOSYS;
+
+ if (!range_is_allowed(vma->vm_pgoff, size))
+ return -EPERM;
+
+ if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
+ &vma->vm_page_prot))
+ return -EINVAL;
+
+ vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
+ size,
+ vma->vm_page_prot);
+
+ vma->vm_ops = &mmap_mem_ops;
+
+ /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
+ if (remap_pfn_range(vma,
+ vma->vm_start,
+ vma->vm_pgoff,
+ size,
+ vma->vm_page_prot)) {
+ unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_DEVKMEM
+static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
+{
+ unsigned long pfn;
+
+ /* Turn a kernel-virtual address into a physical page frame */
+ pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
+
+ /*
+ * RED-PEN: on some architectures there is more mapped memory
+ * than available in mem_map which pfn_valid checks
+ * for. Perhaps should add a new macro here.
+ *
+ * RED-PEN: vmalloc is not supported right now.
+ */
+ if (!pfn_valid(pfn))
+ return -EIO;
+
+ vma->vm_pgoff = pfn;
+ return mmap_mem(file, vma);
+}
+#endif
+
+#ifdef CONFIG_CRASH_DUMP
+/*
+ * Read memory corresponding to the old kernel.
+ */
+static ssize_t read_oldmem(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long pfn, offset;
+ size_t read = 0, csize;
+ int rc = 0;
+
+ while (count) {
+ pfn = *ppos / PAGE_SIZE;
+ if (pfn > saved_max_pfn)
+ return read;
+
+ offset = (unsigned long)(*ppos % PAGE_SIZE);
+ if (count > PAGE_SIZE - offset)
+ csize = PAGE_SIZE - offset;
+ else
+ csize = count;
+
+ rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
+ if (rc < 0)
+ return rc;
+ buf += csize;
+ *ppos += csize;
+ read += csize;
+ count -= csize;
+ }
+ return read;
+}
+#endif
+
+extern long vread(char *buf, char *addr, unsigned long count);
+extern long vwrite(char *buf, char *addr, unsigned long count);
+
+#ifdef CONFIG_DEVKMEM
+/*
+ * This function reads the *virtual* memory as seen by the kernel.
+ */
+static ssize_t read_kmem(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t low_count, read, sz;
+ char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
+
+ read = 0;
+ if (p < (unsigned long) high_memory) {
+ low_count = count;
+ if (count > (unsigned long) high_memory - p)
+ low_count = (unsigned long) high_memory - p;
+
+#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
+ /* we don't have page 0 mapped on sparc and m68k.. */
+ if (p < PAGE_SIZE && low_count > 0) {
+ size_t tmp = PAGE_SIZE - p;
+ if (tmp > low_count) tmp = low_count;
+ if (clear_user(buf, tmp))
+ return -EFAULT;
+ buf += tmp;
+ p += tmp;
+ read += tmp;
+ low_count -= tmp;
+ count -= tmp;
+ }
+#endif
+ while (low_count > 0) {
+ /*
+ * Handle first page in case it's not aligned
+ */
+ if (-p & (PAGE_SIZE - 1))
+ sz = -p & (PAGE_SIZE - 1);
+ else
+ sz = PAGE_SIZE;
+
+ sz = min_t(unsigned long, sz, low_count);
+
+ /*
+ * On ia64 if a page has been mapped somewhere as
+ * uncached, then it must also be accessed uncached
+ * by the kernel or data corruption may occur
+ */
+ kbuf = xlate_dev_kmem_ptr((char *)p);
+
+ if (copy_to_user(buf, kbuf, sz))
+ return -EFAULT;
+ buf += sz;
+ p += sz;
+ read += sz;
+ low_count -= sz;
+ count -= sz;
+ }
+ }
+
+ if (count > 0) {
+ kbuf = (char *)__get_free_page(GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+ while (count > 0) {
+ int len = count;
+
+ if (len > PAGE_SIZE)
+ len = PAGE_SIZE;
+ len = vread(kbuf, (char *)p, len);
+ if (!len)
+ break;
+ if (copy_to_user(buf, kbuf, len)) {
+ free_page((unsigned long)kbuf);
+ return -EFAULT;
+ }
+ count -= len;
+ buf += len;
+ read += len;
+ p += len;
+ }
+ free_page((unsigned long)kbuf);
+ }
+ *ppos = p;
+ return read;
+}
+
+
+static inline ssize_t
+do_write_kmem(void *p, unsigned long realp, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t written, sz;
+ unsigned long copied;
+
+ written = 0;
+#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
+ /* we don't have page 0 mapped on sparc and m68k.. */
+ if (realp < PAGE_SIZE) {
+ unsigned long sz = PAGE_SIZE - realp;
+ if (sz > count)
+ sz = count;
+ /* Hmm. Do something? */
+ buf += sz;
+ p += sz;
+ realp += sz;
+ count -= sz;
+ written += sz;
+ }
+#endif
+
+ while (count > 0) {
+ char *ptr;
+ /*
+ * Handle first page in case it's not aligned
+ */
+ if (-realp & (PAGE_SIZE - 1))
+ sz = -realp & (PAGE_SIZE - 1);
+ else
+ sz = PAGE_SIZE;
+
+ sz = min_t(unsigned long, sz, count);
+
+ /*
+ * On ia64 if a page has been mapped somewhere as
+ * uncached, then it must also be accessed uncached
+ * by the kernel or data corruption may occur
+ */
+ ptr = xlate_dev_kmem_ptr(p);
+
+ copied = copy_from_user(ptr, buf, sz);
+ if (copied) {
+ written += sz - copied;
+ if (written)
+ break;
+ return -EFAULT;
+ }
+ buf += sz;
+ p += sz;
+ realp += sz;
+ count -= sz;
+ written += sz;
+ }
+
+ *ppos += written;
+ return written;
+}
+
+
+/*
+ * This function writes to the *virtual* memory as seen by the kernel.
+ */
+static ssize_t write_kmem(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t wrote = 0;
+ ssize_t virtr = 0;
+ ssize_t written;
+ char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
+
+ if (p < (unsigned long) high_memory) {
+
+ wrote = count;
+ if (count > (unsigned long) high_memory - p)
+ wrote = (unsigned long) high_memory - p;
+
+ written = do_write_kmem((void*)p, p, buf, wrote, ppos);
+ if (written != wrote)
+ return written;
+ wrote = written;
+ p += wrote;
+ buf += wrote;
+ count -= wrote;
+ }
+
+ if (count > 0) {
+ kbuf = (char *)__get_free_page(GFP_KERNEL);
+ if (!kbuf)
+ return wrote ? wrote : -ENOMEM;
+ while (count > 0) {
+ int len = count;
+
+ if (len > PAGE_SIZE)
+ len = PAGE_SIZE;
+ if (len) {
+ written = copy_from_user(kbuf, buf, len);
+ if (written) {
+ if (wrote + virtr)
+ break;
+ free_page((unsigned long)kbuf);
+ return -EFAULT;
+ }
+ }
+ len = vwrite(kbuf, (char *)p, len);
+ count -= len;
+ buf += len;
+ virtr += len;
+ p += len;
+ }
+ free_page((unsigned long)kbuf);
+ }
+
+ *ppos = p;
+ return virtr + wrote;
+}
+#endif
+
+#ifdef CONFIG_DEVPORT
+static ssize_t read_port(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long i = *ppos;
+ char __user *tmp = buf;
+
+ if (!access_ok(VERIFY_WRITE, buf, count))
+ return -EFAULT;
+ while (count-- > 0 && i < 65536) {
+ if (__put_user(inb(i),tmp) < 0)
+ return -EFAULT;
+ i++;
+ tmp++;
+ }
+ *ppos = i;
+ return tmp-buf;
+}
+
+static ssize_t write_port(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long i = *ppos;
+ const char __user * tmp = buf;
+
+ if (!access_ok(VERIFY_READ,buf,count))
+ return -EFAULT;
+ while (count-- > 0 && i < 65536) {
+ char c;
+ if (__get_user(c, tmp)) {
+ if (tmp > buf)
+ break;
+ return -EFAULT;
+ }
+ outb(c,i);
+ i++;
+ tmp++;
+ }
+ *ppos = i;
+ return tmp-buf;
+}
+#endif
+
+static ssize_t read_null(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static ssize_t write_null(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ return count;
+}
+
+static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
+ struct splice_desc *sd)
+{
+ return sd->len;
+}
+
+static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out,
+ loff_t *ppos, size_t len, unsigned int flags)
+{
+ return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
+}
+
+static ssize_t read_zero(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ size_t written;
+
+ if (!count)
+ return 0;
+
+ if (!access_ok(VERIFY_WRITE, buf, count))
+ return -EFAULT;
+
+ written = 0;
+ while (count) {
+ unsigned long unwritten;
+ size_t chunk = count;
+
+ if (chunk > PAGE_SIZE)
+ chunk = PAGE_SIZE; /* Just for latency reasons */
+ unwritten = clear_user(buf, chunk);
+ written += chunk - unwritten;
+ if (unwritten)
+ break;
+ buf += chunk;
+ count -= chunk;
+ cond_resched();
+ }
+ return written ? written : -EFAULT;
+}
+
+static int mmap_zero(struct file * file, struct vm_area_struct * vma)
+{
+#ifndef CONFIG_MMU
+ return -ENOSYS;
+#endif
+ if (vma->vm_flags & VM_SHARED)
+ return shmem_zero_setup(vma);
+ return 0;
+}
+
+static ssize_t write_full(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ return -ENOSPC;
+}
+
+/*
+ * Special lseek() function for /dev/null and /dev/zero. Most notably, you
+ * can fopen() both devices with "a" now. This was previously impossible.
+ * -- SRB.
+ */
+
+static loff_t null_lseek(struct file * file, loff_t offset, int orig)
+{
+ return file->f_pos = 0;
+}
+
+/*
+ * 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,
+ * though, in that case (0).
+ *
+ * also note that seeking relative to the "end of file" isn't supported:
+ * it has no meaning, so it returns -EINVAL.
+ */
+static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
+{
+ loff_t ret;
+
+ mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
+ switch (orig) {
+ case 0:
+ file->f_pos = offset;
+ ret = file->f_pos;
+ force_successful_syscall_return();
+ break;
+ case 1:
+ file->f_pos += offset;
+ ret = file->f_pos;
+ force_successful_syscall_return();
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ return ret;
+}
+
+static int open_port(struct inode * inode, struct file * filp)
+{
+ return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
+}
+
+#define zero_lseek null_lseek
+#define full_lseek null_lseek
+#define write_zero write_null
+#define read_full read_zero
+#define open_mem open_port
+#define open_kmem open_mem
+#define open_oldmem open_mem
+
+static const struct file_operations mem_fops = {
+ .llseek = memory_lseek,
+ .read = read_mem,
+ .write = write_mem,
+ .mmap = mmap_mem,
+ .open = open_mem,
+ .get_unmapped_area = get_unmapped_area_mem,
+};
+
+#ifdef CONFIG_DEVKMEM
+static const struct file_operations kmem_fops = {
+ .llseek = memory_lseek,
+ .read = read_kmem,
+ .write = write_kmem,
+ .mmap = mmap_kmem,
+ .open = open_kmem,
+ .get_unmapped_area = get_unmapped_area_mem,
+};
+#endif
+
+static const struct file_operations null_fops = {
+ .llseek = null_lseek,
+ .read = read_null,
+ .write = write_null,
+ .splice_write = splice_write_null,
+};
+
+#ifdef CONFIG_DEVPORT
+static const struct file_operations 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,
+ .read = read_zero,
+ .write = write_zero,
+ .mmap = mmap_zero,
+};
+
+/*
+ * capabilities for /dev/zero
+ * - permits private mappings, "copies" are taken of the source of zeros
+ */
+static struct backing_dev_info zero_bdi = {
+ .capabilities = BDI_CAP_MAP_COPY,
+};
+
+static const struct file_operations full_fops = {
+ .llseek = full_lseek,
+ .read = read_full,
+ .write = write_full,
+};
+
+#ifdef CONFIG_CRASH_DUMP
+static const struct file_operations oldmem_fops = {
+ .read = read_oldmem,
+ .open = open_oldmem,
+};
+#endif
+
+static ssize_t kmsg_write(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ char *tmp;
+ ssize_t ret;
+
+ tmp = kmalloc(count + 1, GFP_KERNEL);
+ if (tmp == NULL)
+ return -ENOMEM;
+ ret = -EFAULT;
+ if (!copy_from_user(tmp, buf, count)) {
+ tmp[count] = 0;
+ ret = printk("%s", tmp);
+ if (ret > count)
+ /* printk can add a prefix */
+ ret = count;
+ }
+ kfree(tmp);
+ return ret;
+}
+
+static const struct file_operations kmsg_fops = {
+ .write = kmsg_write,
+};
+
+static int memory_open(struct inode * inode, struct file * filp)
+{
+ int ret = 0;
+
+ lock_kernel();
+ switch (iminor(inode)) {
+ case 1:
+ filp->f_op = &mem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
+ break;
+#ifdef CONFIG_DEVKMEM
+ case 2:
+ filp->f_op = &kmem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
+ break;
+#endif
+ case 3:
+ filp->f_op = &null_fops;
+ break;
+#ifdef CONFIG_DEVPORT
+ case 4:
+ filp->f_op = &port_fops;
+ break;
+#endif
+ case 5:
+ filp->f_mapping->backing_dev_info = &zero_bdi;
+ filp->f_op = &zero_fops;
+ break;
+ case 7:
+ filp->f_op = &full_fops;
+ break;
+ case 8:
+ filp->f_op = &random_fops;
+ break;
+ case 9:
+ filp->f_op = &urandom_fops;
+ break;
+ case 11:
+ filp->f_op = &kmsg_fops;
+ break;
+#ifdef CONFIG_CRASH_DUMP
+ case 12:
+ filp->f_op = &oldmem_fops;
+ break;
+#endif
+ default:
+ unlock_kernel();
+ return -ENXIO;
+ }
+ if (filp->f_op && filp->f_op->open)
+ ret = filp->f_op->open(inode,filp);
+ unlock_kernel();
+ return ret;
+}
+
+static const struct file_operations memory_fops = {
+ .open = memory_open, /* just a selector for the real open */
+};
+
+static const struct {
+ unsigned int minor;
+ char *name;
+ umode_t mode;
+ const struct file_operations *fops;
+} devlist[] = { /* list of minor devices */
+ {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
+#ifdef CONFIG_DEVKMEM
+ {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
+#endif
+ {3, "null", S_IRUGO | S_IWUGO, &null_fops},
+#ifdef CONFIG_DEVPORT
+ {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
+#endif
+ {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
+ {7, "full", S_IRUGO | S_IWUGO, &full_fops},
+ {8, "random", S_IRUGO | S_IWUSR, &random_fops},
+ {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
+ {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
+#ifdef CONFIG_CRASH_DUMP
+ {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
+#endif
+};
+
+static struct class *mem_class;
+
+static int __init chr_dev_init(void)
+{
+ int i;
+ 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);
+
+ mem_class = class_create(THIS_MODULE, "mem");
+ for (i = 0; i < ARRAY_SIZE(devlist); i++)
+ device_create(mem_class, NULL,
+ MKDEV(MEM_MAJOR, devlist[i].minor), NULL,
+ devlist[i].name);
+
+ return 0;
+}
+
+fs_initcall(chr_dev_init);
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