* Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
*/
-#include <linux/config.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
-#include <linux/devfs_fs_kernel.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/pipe_fs_i.h>
+#include <linux/pfn.h>
#include <asm/uaccess.h>
#include <asm/io.h>
# include <linux/efi.h>
#endif
-#if defined(CONFIG_S390_TAPE) && defined(CONFIG_S390_TAPE_CHAR)
-extern void tapechar_init(void);
-#endif
-
static inline int range_is_allowed(unsigned long from, unsigned long to)
{
unsigned long cursor;
cursor = from >> PAGE_SHIFT;
while ((cursor << PAGE_SHIFT) < to) {
if (!devmem_is_allowed(cursor)) {
- printk ("Program %s tried to read /dev/mem between %lx->%lx."
- "We stopped at %lx\n", current->comm, from, to, cursor);
+ printk ("Program %s tried to read /dev/mem between %lx->%lx.\n",
+ current->comm, from, to);
return 0;
}
cursor++;
}
#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
-static inline int valid_phys_addr_range(unsigned long addr, size_t *count)
+static inline int valid_phys_addr_range(unsigned long addr, size_t count)
{
- unsigned long end_mem;
-
- end_mem = __pa(high_memory);
- if (addr >= end_mem)
+ if (addr + count > __pa(high_memory))
return 0;
- if (*count > end_mem - addr)
- *count = end_mem - addr;
+ return 1;
+}
+static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
+{
return 1;
}
#endif
ssize_t read, sz;
char *ptr;
- if (!valid_phys_addr_range(p, &count))
+ if (!valid_phys_addr_range(p, count))
return -EFAULT;
read = 0;
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
unsigned long copied;
void *ptr;
- if (!valid_phys_addr_range(p, &count))
+ if (!valid_phys_addr_range(p, count))
return -EFAULT;
written = 0;
return -EPERM;
copied = copy_from_user(ptr, buf, sz);
if (copied) {
- ssize_t ret;
-
- ret = written + (sz - copied);
- if (ret)
- return ret;
+ written += sz - copied;
+ if (written)
+ break;
return -EFAULT;
}
buf += sz;
}
#endif
-static int mmap_mem(struct file * file, struct vm_area_struct * vma)
+#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)
{
-#if defined(__HAVE_PHYS_MEM_ACCESS_PROT)
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+#ifdef pgprot_noncached
+ unsigned long offset = pfn << PAGE_SHIFT;
- vma->vm_page_prot = phys_mem_access_prot(file, offset,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
-#elif defined(pgprot_noncached)
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
- int uncached;
+ 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;
+}
- uncached = uncached_access(file, offset);
- if (uncached)
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+/* 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
+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;
+
+ vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
+ size,
+ vma->vm_page_prot);
+
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
- vma->vm_end-vma->vm_start,
+ size,
vma->vm_page_prot))
return -EAGAIN;
return 0;
}
+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);
+}
+
#ifdef CONFIG_CRASH_DUMP
/*
* Read memory corresponding to the old kernel.
- * If we are reading from the reserved section, which is
- * actually used by the current kernel, we just return zeroes.
- * Or if we are reading from the first 640k, we return from the
- * backed up area.
*/
-static ssize_t read_oldmem(struct file * file, char * buf,
+static ssize_t read_oldmem(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
- unsigned long pfn;
- unsigned backup_start, backup_end, relocate_start;
- size_t read=0, csize;
-
- backup_start = CRASH_BACKUP_BASE / PAGE_SIZE;
- backup_end = backup_start + (CRASH_BACKUP_SIZE / PAGE_SIZE);
- relocate_start = (CRASH_BACKUP_BASE + CRASH_BACKUP_SIZE) / PAGE_SIZE;
+ unsigned long pfn, offset;
+ size_t read = 0, csize;
+ int rc = 0;
- while(count) {
+ while (count) {
pfn = *ppos / PAGE_SIZE;
+ if (pfn > saved_max_pfn)
+ return read;
- csize = (count > PAGE_SIZE) ? PAGE_SIZE : count;
-
- /* Perform translation (see comment above) */
- if ((pfn >= backup_start) && (pfn < backup_end)) {
- if (clear_user(buf, csize)) {
- read = -EFAULT;
- goto done;
- }
-
- goto copy_done;
- } else if (pfn < (CRASH_RELOCATE_SIZE / PAGE_SIZE))
- pfn += relocate_start;
-
- if (pfn > saved_max_pfn) {
- read = 0;
- goto done;
- }
-
- if (copy_oldmem_page(pfn, buf, csize, 1)) {
- read = -EFAULT;
- goto done;
- }
+ offset = (unsigned long)(*ppos % PAGE_SIZE);
+ if (count > PAGE_SIZE - offset)
+ csize = PAGE_SIZE - offset;
+ else
+ csize = count;
-copy_done:
+ rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
+ if (rc < 0)
+ return rc;
buf += csize;
*ppos += csize;
read += csize;
count -= csize;
}
-done:
return read;
}
#endif
-static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
-{
- unsigned long long val;
- /*
- * 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(vma->vm_pgoff))
- return -EIO;
- val = (u64)vma->vm_pgoff << PAGE_SHIFT;
- vma->vm_pgoff = __pa(val) >> PAGE_SHIFT;
- return mmap_mem(file, vma);
-}
-
extern long vread(char *buf, char *addr, unsigned long count);
extern long vwrite(char *buf, char *addr, unsigned long count);
return read;
}
-
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
static ssize_t read_port(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
return -EFAULT;
while (count-- > 0 && i < 65536) {
char c;
- if (__get_user(c, tmp))
+ if (__get_user(c, tmp)) {
+ if (tmp > buf)
+ break;
return -EFAULT;
+ }
outb(c,i);
i++;
tmp++;
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);
+}
+
#ifdef CONFIG_MMU
/*
* For fun, we are using the MMU for this.
count = size;
zap_page_range(vma, addr, count, NULL);
- zeromap_page_range(vma, addr, count, PAGE_COPY);
+ if (zeromap_page_range(vma, addr, count, PAGE_COPY))
+ break;
size -= count;
buf += count;
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
{
+ int err;
+
if (vma->vm_flags & VM_SHARED)
return shmem_zero_setup(vma);
- if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
- return -EAGAIN;
- return 0;
+ err = zeromap_page_range(vma, vma->vm_start,
+ vma->vm_end - vma->vm_start, vma->vm_page_prot);
+ BUG_ON(err == -EEXIST);
+ return err;
}
#else /* CONFIG_MMU */
static ssize_t read_zero(struct file * file, char * buf,
{
loff_t ret;
- down(&file->f_dentry->d_inode->i_sem);
+ mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
switch (orig) {
case 0:
file->f_pos = offset;
default:
ret = -EINVAL;
}
- up(&file->f_dentry->d_inode->i_sem);
+ mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
return ret;
}
#define open_oldmem open_mem
#ifndef ARCH_HAS_DEV_MEM
-static struct file_operations mem_fops = {
+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,
};
#else
extern struct file_operations mem_fops;
#endif
-static struct file_operations kmem_fops = {
+static const struct file_operations kmem_fops = {
.llseek = memory_lseek,
.read = read_kmem,
.mmap = mmap_kmem,
.open = open_kmem,
+ .get_unmapped_area = get_unmapped_area_mem,
};
-static struct file_operations null_fops = {
+static const struct file_operations null_fops = {
.llseek = null_lseek,
.read = read_null,
.write = write_null,
+ .splice_write = splice_write_null,
};
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
-static struct file_operations port_fops = {
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+static const struct file_operations port_fops = {
.llseek = memory_lseek,
.read = read_port,
.write = write_port,
};
#endif
-static struct file_operations zero_fops = {
+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 struct file_operations full_fops = {
+static const struct file_operations full_fops = {
.llseek = full_lseek,
.read = read_full,
.write = write_full,
};
#ifdef CONFIG_CRASH_DUMP
-static struct file_operations oldmem_fops = {
+static const struct file_operations oldmem_fops = {
.read = read_oldmem,
.open = open_oldmem,
};
size_t count, loff_t *ppos)
{
char *tmp;
- int ret;
+ ssize_t ret;
tmp = kmalloc(count + 1, GFP_KERNEL);
if (tmp == NULL)
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 struct file_operations kmsg_fops = {
+static const struct file_operations kmsg_fops = {
.write = kmsg_write,
};
switch (iminor(inode)) {
case 1:
filp->f_op = &mem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
case 2:
filp->f_op = &kmem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
case 3:
filp->f_op = &null_fops;
break;
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
case 4:
filp->f_op = &port_fops;
break;
return 0;
}
-static struct file_operations memory_fops = {
+static const struct file_operations memory_fops = {
.open = memory_open, /* just a selector for the real open */
};
unsigned int minor;
char *name;
umode_t mode;
- struct file_operations *fops;
+ const struct file_operations *fops;
} devlist[] = { /* list of minor devices */
{1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
{3, "null", S_IRUGO | S_IWUGO, &null_fops},
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
{4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
#endif
{5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
#endif
};
-static struct class_simple *mem_class;
+static struct class *mem_class;
static int __init chr_dev_init(void)
{
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
printk("unable to get major %d for memory devs\n", MEM_MAJOR);
- mem_class = class_simple_create(THIS_MODULE, "mem");
- for (i = 0; i < ARRAY_SIZE(devlist); i++) {
- class_simple_device_add(mem_class,
- MKDEV(MEM_MAJOR, devlist[i].minor),
- NULL, devlist[i].name);
- devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
- S_IFCHR | devlist[i].mode, devlist[i].name);
- }
-
+ 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),
+ devlist[i].name);
+
return 0;
}
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