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path: root/drivers/char/mem.c
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Diffstat (limited to 'drivers/char/mem.c')
-rw-r--r--drivers/char/mem.c165
1 files changed, 71 insertions, 94 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 1256454b2d4..917403fe10d 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -21,19 +21,21 @@
#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/export.h>
+#include <linux/io.h>
+#include <linux/aio.h>
#include <asm/uaccess.h>
-#include <asm/io.h>
#ifdef CONFIG_IA64
# include <linux/efi.h>
#endif
+#define DEVPORT_MINOR 4
+
static inline unsigned long size_inside_page(unsigned long start,
unsigned long size)
{
@@ -45,12 +47,9 @@ static inline unsigned long size_inside_page(unsigned long start,
}
#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(phys_addr_t addr, size_t count)
{
- if (addr + count > __pa(high_memory))
- return 0;
-
- return 1;
+ return addr + count <= __pa(high_memory);
}
static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
@@ -96,10 +95,13 @@ void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr)
static ssize_t read_mem(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
- unsigned long p = *ppos;
+ phys_addr_t p = *ppos;
ssize_t read, sz;
char *ptr;
+ if (p != *ppos)
+ return 0;
+
if (!valid_phys_addr_range(p, count))
return -EFAULT;
read = 0;
@@ -153,11 +155,14 @@ static ssize_t read_mem(struct file *file, char __user *buf,
static ssize_t write_mem(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- unsigned long p = *ppos;
+ phys_addr_t p = *ppos;
ssize_t written, sz;
unsigned long copied;
void *ptr;
+ if (p != *ppos)
+ return -EFBIG;
+
if (!valid_phys_addr_range(p, count))
return -EFAULT;
@@ -226,7 +231,7 @@ int __weak phys_mem_access_prot_allowed(struct file *file,
*
*/
#ifdef pgprot_noncached
-static int uncached_access(struct file *file, unsigned long addr)
+static int uncached_access(struct file *file, phys_addr_t addr)
{
#if defined(CONFIG_IA64)
/*
@@ -258,7 +263,7 @@ 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;
+ phys_addr_t offset = pfn << PAGE_SHIFT;
if (uncached_access(file, offset))
return pgprot_noncached(vma_prot);
@@ -322,7 +327,7 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma)
vma->vm_ops = &mmap_mem_ops;
- /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
+ /* Remap-pfn-range will mark the range VM_IO */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
@@ -356,40 +361,6 @@ static int mmap_kmem(struct file *file, struct vm_area_struct *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
-
#ifdef CONFIG_DEVKMEM
/*
* This function reads the *virtual* memory as seen by the kernel.
@@ -399,7 +370,7 @@ static ssize_t read_kmem(struct file *file, char __user *buf,
{
unsigned long p = *ppos;
ssize_t low_count, read, sz;
- char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
+ char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
int err = 0;
read = 0;
@@ -527,7 +498,7 @@ static ssize_t write_kmem(struct file *file, const char __user *buf,
unsigned long p = *ppos;
ssize_t wrote = 0;
ssize_t virtr = 0;
- char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
+ char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
int err = 0;
if (p < (unsigned long) high_memory) {
@@ -595,7 +566,7 @@ 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;
+ const char __user *tmp = buf;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
@@ -627,6 +598,18 @@ static ssize_t write_null(struct file *file, const char __user *buf,
return count;
}
+static ssize_t aio_read_null(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ return 0;
+}
+
+static ssize_t aio_write_null(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ return iov_length(iov, nr_segs);
+}
+
static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
struct splice_desc *sd)
{
@@ -670,6 +653,24 @@ static ssize_t read_zero(struct file *file, char __user *buf,
return written ? written : -EFAULT;
}
+static ssize_t aio_read_zero(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ size_t written = 0;
+ unsigned long i;
+ ssize_t ret;
+
+ for (i = 0; i < nr_segs; i++) {
+ ret = read_zero(iocb->ki_filp, iov[i].iov_base, iov[i].iov_len,
+ &pos);
+ if (ret < 0)
+ break;
+ written += ret;
+ }
+
+ return written ? written : -EFAULT;
+}
+
static int mmap_zero(struct file *file, struct vm_area_struct *vma)
{
#ifndef CONFIG_MMU
@@ -708,13 +709,13 @@ 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);
+ mutex_lock(&file_inode(file)->i_mutex);
switch (orig) {
case SEEK_CUR:
offset += file->f_pos;
case SEEK_SET:
/* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */
- if ((unsigned long long)offset >= ~0xFFFULL) {
+ if (IS_ERR_VALUE((unsigned long long)offset)) {
ret = -EOVERFLOW;
break;
}
@@ -725,11 +726,11 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
default:
ret = -EINVAL;
}
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&file_inode(file)->i_mutex);
return ret;
}
-static int open_port(struct inode * inode, struct file * filp)
+static int open_port(struct inode *inode, struct file *filp)
{
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}
@@ -738,9 +739,9 @@ static int open_port(struct inode * inode, struct file * filp)
#define full_lseek null_lseek
#define write_zero write_null
#define read_full read_zero
+#define aio_write_zero aio_write_null
#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,
@@ -766,6 +767,8 @@ static const struct file_operations null_fops = {
.llseek = null_lseek,
.read = read_null,
.write = write_null,
+ .aio_read = aio_read_null,
+ .aio_write = aio_write_null,
.splice_write = splice_write_null,
};
@@ -782,6 +785,8 @@ static const struct file_operations zero_fops = {
.llseek = zero_lseek,
.read = read_zero,
.write = write_zero,
+ .aio_read = aio_read_zero,
+ .aio_write = aio_write_zero,
.mmap = mmap_zero,
};
@@ -801,43 +806,9 @@ static const struct file_operations full_fops = {
.write = write_full,
};
-#ifdef CONFIG_CRASH_DUMP
-static const struct file_operations oldmem_fops = {
- .read = read_oldmem,
- .open = open_oldmem,
- .llseek = default_llseek,
-};
-#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,
- .llseek = noop_llseek,
-};
-
static const struct memdev {
const char *name;
- mode_t mode;
+ umode_t mode;
const struct file_operations *fops;
struct backing_dev_info *dev_info;
} devlist[] = {
@@ -853,9 +824,8 @@ static const struct memdev {
[7] = { "full", 0666, &full_fops, NULL },
[8] = { "random", 0666, &random_fops, NULL },
[9] = { "urandom", 0666, &urandom_fops, NULL },
- [11] = { "kmsg", 0, &kmsg_fops, NULL },
-#ifdef CONFIG_CRASH_DUMP
- [12] = { "oldmem", 0, &oldmem_fops, NULL },
+#ifdef CONFIG_PRINTK
+ [11] = { "kmsg", 0644, &kmsg_fops, NULL },
#endif
};
@@ -891,7 +861,7 @@ static const struct file_operations memory_fops = {
.llseek = noop_llseek,
};
-static char *mem_devnode(struct device *dev, mode_t *mode)
+static char *mem_devnode(struct device *dev, umode_t *mode)
{
if (mode && devlist[MINOR(dev->devt)].mode)
*mode = devlist[MINOR(dev->devt)].mode;
@@ -920,6 +890,13 @@ static int __init chr_dev_init(void)
for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
if (!devlist[minor].name)
continue;
+
+ /*
+ * Create /dev/port?
+ */
+ if ((minor == DEVPORT_MINOR) && !arch_has_dev_port())
+ continue;
+
device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor),
NULL, devlist[minor].name);
}