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>

1 files changed, 4 insertions, 10 deletions

diff --git a/sound/isa/gus/gus_mem_proc.c b/sound/isa/gus/gus_mem_proc.c
index b2d2dba6c860..faa2bec8f6b6 100644
--- a/sound/isa/gus/gus_mem_proc.c
+++ b/sound/isa/gus/gus_mem_proc.c
@@ -36,20 +36,14 @@ static ssize_t snd_gf1_mem_proc_dump(struct snd_info_entry *entry,
                                      struct file *file, char __user *buf,
                                      size_t count, loff_t pos)
 {
-        long size;
         struct gus_proc_private *priv = entry->private_data;
         struct snd_gus_card *gus = priv->gus;
         int err;
 
-        size = count;
-        if (pos + size > priv->size)
-                size = (long)priv->size - pos;
-        if (size > 0) {
-                if ((err = snd_gus_dram_read(gus, buf, pos, size, priv->rom)) < 0)
-                        return err;
-                return size;
-        }
-        return 0;
+        err = snd_gus_dram_read(gus, buf, pos, count, priv->rom);
+        if (err < 0)
+                return err;
+        return count;
 }                       
 
 static loff_t snd_gf1_mem_proc_llseek(struct snd_info_entry *entry,