proc: unify mem_read() and mem_write()
No functional changes, cleanup and preparation. mem_read() and mem_write() are very similar. Move this code into the new common helper, mem_rw(), which takes the additional "int write" argument. Cc: stable@kernel.org Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
71879d3cb3
commit
572d34b946
|
@ -718,57 +718,13 @@ static int mem_open(struct inode* inode, struct file* file)
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
static ssize_t mem_read(struct file * file, char __user * buf,
|
static ssize_t mem_rw(struct file *file, char __user *buf,
|
||||||
size_t count, loff_t *ppos)
|
size_t count, loff_t *ppos, int write)
|
||||||
{
|
{
|
||||||
int ret;
|
|
||||||
char *page;
|
|
||||||
unsigned long src = *ppos;
|
|
||||||
struct mm_struct *mm = file->private_data;
|
struct mm_struct *mm = file->private_data;
|
||||||
|
unsigned long addr = *ppos;
|
||||||
if (!mm)
|
ssize_t copied;
|
||||||
return 0;
|
|
||||||
|
|
||||||
page = (char *)__get_free_page(GFP_TEMPORARY);
|
|
||||||
if (!page)
|
|
||||||
return -ENOMEM;
|
|
||||||
|
|
||||||
ret = 0;
|
|
||||||
|
|
||||||
while (count > 0) {
|
|
||||||
int this_len, retval;
|
|
||||||
|
|
||||||
this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
|
|
||||||
retval = access_remote_vm(mm, src, page, this_len, 0);
|
|
||||||
if (!retval) {
|
|
||||||
if (!ret)
|
|
||||||
ret = -EIO;
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
|
|
||||||
if (copy_to_user(buf, page, retval)) {
|
|
||||||
ret = -EFAULT;
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
|
|
||||||
ret += retval;
|
|
||||||
src += retval;
|
|
||||||
buf += retval;
|
|
||||||
count -= retval;
|
|
||||||
}
|
|
||||||
*ppos = src;
|
|
||||||
|
|
||||||
free_page((unsigned long) page);
|
|
||||||
return ret;
|
|
||||||
}
|
|
||||||
|
|
||||||
static ssize_t mem_write(struct file * file, const char __user *buf,
|
|
||||||
size_t count, loff_t *ppos)
|
|
||||||
{
|
|
||||||
int copied;
|
|
||||||
char *page;
|
char *page;
|
||||||
unsigned long dst = *ppos;
|
|
||||||
struct mm_struct *mm = file->private_data;
|
|
||||||
|
|
||||||
if (!mm)
|
if (!mm)
|
||||||
return 0;
|
return 0;
|
||||||
|
@ -779,30 +735,48 @@ static ssize_t mem_write(struct file * file, const char __user *buf,
|
||||||
|
|
||||||
copied = 0;
|
copied = 0;
|
||||||
while (count > 0) {
|
while (count > 0) {
|
||||||
int this_len, retval;
|
int this_len = min_t(int, count, PAGE_SIZE);
|
||||||
|
|
||||||
this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
|
if (write && copy_from_user(page, buf, this_len)) {
|
||||||
if (copy_from_user(page, buf, this_len)) {
|
|
||||||
copied = -EFAULT;
|
copied = -EFAULT;
|
||||||
break;
|
break;
|
||||||
}
|
}
|
||||||
retval = access_remote_vm(mm, dst, page, this_len, 1);
|
|
||||||
if (!retval) {
|
this_len = access_remote_vm(mm, addr, page, this_len, write);
|
||||||
|
if (!this_len) {
|
||||||
if (!copied)
|
if (!copied)
|
||||||
copied = -EIO;
|
copied = -EIO;
|
||||||
break;
|
break;
|
||||||
}
|
}
|
||||||
copied += retval;
|
|
||||||
buf += retval;
|
if (!write && copy_to_user(buf, page, this_len)) {
|
||||||
dst += retval;
|
copied = -EFAULT;
|
||||||
count -= retval;
|
break;
|
||||||
|
}
|
||||||
|
|
||||||
|
buf += this_len;
|
||||||
|
addr += this_len;
|
||||||
|
copied += this_len;
|
||||||
|
count -= this_len;
|
||||||
}
|
}
|
||||||
*ppos = dst;
|
*ppos = addr;
|
||||||
|
|
||||||
free_page((unsigned long) page);
|
free_page((unsigned long) page);
|
||||||
return copied;
|
return copied;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static ssize_t mem_read(struct file *file, char __user *buf,
|
||||||
|
size_t count, loff_t *ppos)
|
||||||
|
{
|
||||||
|
return mem_rw(file, buf, count, ppos, 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
static ssize_t mem_write(struct file *file, const char __user *buf,
|
||||||
|
size_t count, loff_t *ppos)
|
||||||
|
{
|
||||||
|
return mem_rw(file, (char __user*)buf, count, ppos, 1);
|
||||||
|
}
|
||||||
|
|
||||||
loff_t mem_lseek(struct file *file, loff_t offset, int orig)
|
loff_t mem_lseek(struct file *file, loff_t offset, int orig)
|
||||||
{
|
{
|
||||||
switch (orig) {
|
switch (orig) {
|
||||||
|
|
Loading…
Reference in a new issue