Re: 2.4.17 agpgart process hang on crash

[Andrew Morton]

Lars Christensen wrote:
> 
> No luck. Still hangs (e.g. with ./testgart & pkill -ABRT testgart), with
> and without that patch and with and without 2.4.18-pre7. Does seem to
> happen when dumping core--it doesn't happen with core dumping disabled.
> 

This one, please:

--- linux-2.4.18-pre7/drivers/char/agp/agpgart_fe.c	Sun Aug 12 10:38:48 2001
+++ linux-akpm/drivers/char/agp/agpgart_fe.c	Sat Feb  2 15:29:49 2002
@@ -605,19 +605,18 @@ static int agp_mmap(struct file *file, s
 	agp_client *client;
 	agp_file_private *priv = (agp_file_private *) file->private_data;
 	agp_kern_info kerninfo;
+	int ret = -EPERM;
 
 	lock_kernel();
 	AGP_LOCK();
 
 	if (agp_fe.backend_acquired != TRUE) {
-		AGP_UNLOCK();
-		unlock_kernel();
-		return -EPERM;
+		ret = -EPERM;
+		goto out;
 	}
 	if (!(test_bit(AGP_FF_IS_VALID, &priv->access_flags))) {
-		AGP_UNLOCK();
-		unlock_kernel();
-		return -EPERM;
+		ret = -EPERM;
+		goto out;
 	}
 	agp_copy_info(&kerninfo);
 	size = vma->vm_end - vma->vm_start;
@@ -627,52 +626,46 @@ static int agp_mmap(struct file *file, s
 
 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
 		if ((size + offset) > current_size) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		client = agp_find_client_by_pid(current->pid);
 
 		if (client == NULL) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EPERM;
+			ret = -EPERM;
+			goto out;
 		}
 		if (!agp_find_seg_in_client(client, offset,
 					    size, vma->vm_page_prot)) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		if (remap_page_range(vma->vm_start,
 				     (kerninfo.aper_base + offset),
 				     size, vma->vm_page_prot)) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EAGAIN;
-		}
-		AGP_UNLOCK();
-		unlock_kernel();
-		return 0;
+			ret = -EAGAIN;
+			goto out;
+		}
+		ret = 0;
+		goto out;
 	}
 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 		if (size != current_size) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		if (remap_page_range(vma->vm_start, kerninfo.aper_base,
 				     size, vma->vm_page_prot)) {
-			AGP_UNLOCK();
-			unlock_kernel();
-			return -EAGAIN;
-		}
-		AGP_UNLOCK();
-		unlock_kernel();
-		return 0;
+			ret = -EAGAIN;
+			goto out;
+		}
+		ret = 0;
 	}
+out:
 	AGP_UNLOCK();
 	unlock_kernel();
+	if (ret == 0)
+		vma->vm_flags |= VM_IO;
 	return -EPERM;
 }