1 files changed, 43 insertions, 49 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 2c644afbcdd..917403fe10d 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -21,13 +21,12 @@
 #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>
 
@@ -100,6 +99,9 @@ static ssize_t read_mem(struct file *file, char __user *buf,
 	ssize_t read, sz;
 	char *ptr;
 
+	if (p != *ppos)
+		return 0;
+
 	if (!valid_phys_addr_range(p, count))
 		return -EFAULT;
 	read = 0;
@@ -158,6 +160,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
 	unsigned long copied;
 	void *ptr;
 
+	if (p != *ppos)
+		return -EFBIG;
+
 	if (!valid_phys_addr_range(p, count))
 		return -EFAULT;
 
@@ -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.
@@ -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
@@ -714,7 +715,7 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
 		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;
 		}
@@ -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,
 };
 
@@ -801,14 +806,6 @@ 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 const struct memdev {
 	const char *name;
 	umode_t mode;
@@ -830,9 +827,6 @@ static const struct memdev {
 #ifdef CONFIG_PRINTK
 	[11] = { "kmsg", 0644, &kmsg_fops, NULL },
 #endif
-#ifdef CONFIG_CRASH_DUMP
-	[12] = { "oldmem", 0, &oldmem_fops, NULL },
-#endif
 };
 
 static int memory_open(struct inode *inode, struct file *filp)