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-rw-r--r--drivers/char/mem.c49
1 files changed, 22 insertions, 27 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 192af59..868ff2c 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -440,19 +440,18 @@ static ssize_t read_kmem(struct file *file, char __user *buf,
if (!kbuf)
return -ENOMEM;
while (count > 0) {
- int len = size_inside_page(p, count);
-
- len = vread(kbuf, (char *)p, len);
- if (!len)
+ sz = size_inside_page(p, count);
+ sz = vread(kbuf, (char *)p, sz);
+ if (!sz)
break;
- if (copy_to_user(buf, kbuf, len)) {
+ if (copy_to_user(buf, kbuf, sz)) {
free_page((unsigned long)kbuf);
return -EFAULT;
}
- count -= len;
- buf += len;
- read += len;
- p += len;
+ count -= sz;
+ buf += sz;
+ read += sz;
+ p += sz;
}
free_page((unsigned long)kbuf);
}
@@ -522,19 +521,14 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
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;
+ unsigned long to_write = min_t(unsigned long, count,
+ (unsigned long)high_memory - p);
+ wrote = do_write_kmem((void *)p, p, buf, to_write, ppos);
+ if (wrote != to_write)
+ return wrote;
p += wrote;
buf += wrote;
count -= wrote;
@@ -545,20 +539,21 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
if (!kbuf)
return wrote ? wrote : -ENOMEM;
while (count > 0) {
- int len = size_inside_page(p, count);
+ unsigned long sz = size_inside_page(p, count);
+ unsigned long n;
- written = copy_from_user(kbuf, buf, len);
- if (written) {
+ n = copy_from_user(kbuf, buf, sz);
+ if (n) {
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;
+ sz = vwrite(kbuf, (char *)p, sz);
+ count -= sz;
+ buf += sz;
+ virtr += sz;
+ p += sz;
}
free_page((unsigned long)kbuf);
}