fixing races

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 1bf594c52f41cc34e70ad4bdc585b0acf87bf004..50e1e9689f22cd8064eb3128f31f1a614ce0ae95 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -478,7 +478,6 @@ static int do_bufinfo_ioctl(comedi_device *dev,void *arg)
                }
        }
        bi.buf_int_count = async->buf_int_count;
-       // XXX why why report the pointer values, they are useless to the user
        bi.buf_int_ptr = async->buf_int_ptr;
        bi.buf_user_count = async->buf_user_count;
        bi.buf_user_ptr = async->buf_user_ptr;
@@ -1349,12 +1348,11 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
 
                n=nbytes;
 
-               if( async->buf_user_ptr < async->buf_int_ptr)
-                       m = async->buf_int_ptr - async->buf_user_ptr;
-               else
+               m = async->buf_int_ptr - async->buf_user_ptr;
+               if( m < 0 )
                        m = async->data_len - async->buf_user_count;
 
-               if(m<n)n=m;
+               if(m < n) n = m;
 
                if(n==0){
                        if(file->f_flags&O_NONBLOCK){
@@ -1380,7 +1378,7 @@ static ssize_t comedi_write_v22(struct file *file,const char *buf,size_t nbytes,
                m=copy_from_user(async->data+async->buf_user_ptr,buf,n);
                if(m) retval=-EFAULT;
                n-=m;
-               
+
                count+=n;
                nbytes-=n;
                async->buf_user_ptr+=n;
@@ -1443,9 +1441,8 @@ static ssize_t comedi_read_v22(struct file * file,char *buf,size_t nbytes,loff_t
 
                n=nbytes;
 
-               if(async->buf_int_ptr >= async->buf_user_ptr)
-                       m = async->buf_int_ptr - async->buf_user_ptr;
-               else
+               m = async->buf_int_ptr - async->buf_user_ptr;
+               if( m < 0 )
                        m = async->data_len - async->buf_user_ptr;
 
 #if 0