ALSA: info - Check file position validity in common layer
Check the validity of the file position in the common info layer before
calling read or write callbacks in assumption that entry->size is set up
properly to indicate the max file size.
Removed the redundant checks from the callbacks as well.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/opl4/opl4_proc.c b/sound/drivers/opl4/opl4_proc.c
index eb72814..210b89d 100644
--- a/sound/drivers/opl4/opl4_proc.c
+++ b/sound/drivers/opl4/opl4_proc.c
@@ -55,25 +55,18 @@
size_t count, loff_t pos)
{
struct snd_opl4 *opl4 = entry->private_data;
- long size;
char* buf;
- size = count;
- if (pos + size > entry->size)
- size = entry->size - pos;
- if (size > 0) {
- buf = vmalloc(size);
- if (!buf)
- return -ENOMEM;
- snd_opl4_read_memory(opl4, buf, pos, size);
- if (copy_to_user(_buf, buf, size)) {
- vfree(buf);
- return -EFAULT;
- }
+ buf = vmalloc(count);
+ if (!buf)
+ return -ENOMEM;
+ snd_opl4_read_memory(opl4, buf, pos, count);
+ if (copy_to_user(_buf, buf, count)) {
vfree(buf);
- return size;
+ return -EFAULT;
}
- return 0;
+ vfree(buf);
+ return count;
}
static ssize_t snd_opl4_mem_proc_write(struct snd_info_entry *entry,
@@ -83,25 +76,18 @@
size_t count, size_t pos)
{
struct snd_opl4 *opl4 = entry->private_data;
- long size;
char *buf;
- size = count;
- if (pos + size > entry->size)
- size = entry->size - pos;
- if (size > 0) {
- buf = vmalloc(size);
- if (!buf)
- return -ENOMEM;
- if (copy_from_user(buf, _buf, size)) {
- vfree(buf);
- return -EFAULT;
- }
- snd_opl4_write_memory(opl4, buf, pos, size);
+ buf = vmalloc(count);
+ if (!buf)
+ return -ENOMEM;
+ if (copy_from_user(buf, _buf, count)) {
vfree(buf);
- return size;
+ return -EFAULT;
}
- return 0;
+ snd_opl4_write_memory(opl4, buf, pos, count);
+ vfree(buf);
+ return count;
}
static loff_t snd_opl4_mem_proc_llseek(struct snd_info_entry *entry,