[2/2] GPU-DRM-Savage: Less function calls in savage_bci_cmdbuf() after error detection
diff mbox series

Message ID c97563c0-d463-8b15-5956-26d93641a54f@users.sourceforge.net
State New, archived
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Series
  • GPU-DRM-Savage: Fine-tuning for savage_bci_cmdbuf()
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Commit Message

SF Markus Elfring Aug. 18, 2016, 7:48 p.m. UTC
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 18 Aug 2016 21:28:58 +0200

The kfree() function was called in a few cases by the
savage_bci_cmdbuf() function during error handling
even if a passed variable contained a null pointer.

Adjust jump targets according to the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/gpu/drm/savage/savage_state.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

Comments

Daniel Vetter Aug. 19, 2016, 7:50 a.m. UTC | #1
On Thu, Aug 18, 2016 at 09:48:04PM +0200, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Thu, 18 Aug 2016 21:28:58 +0200
> 
> The kfree() function was called in a few cases by the
> savage_bci_cmdbuf() function during error handling
> even if a passed variable contained a null pointer.
> 
> Adjust jump targets according to the Linux coding style convention.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Not sure this is worth it, I'll pass. Patch 1 merged. Btw I consider
cocci patches a good way to get started somewhere, but then it's much more
useful to do a bit more involved things. We keep a list of small&big
janitor tasks:

https://www.x.org/wiki/DRMJanitors/

Cleaning up all the cocci errors in drm isn't good since then the next
person won't have something easy to get started, i.e. consider you're
budget used up ;-)
-Daniel

> ---
>  drivers/gpu/drm/savage/savage_state.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/savage/savage_state.c b/drivers/gpu/drm/savage/savage_state.c
> index 3dc0d8f..5b484aa 100644
> --- a/drivers/gpu/drm/savage/savage_state.c
> +++ b/drivers/gpu/drm/savage/savage_state.c
> @@ -1004,7 +1004,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  		kvb_addr = memdup_user(cmdbuf->vb_addr, cmdbuf->vb_size);
>  		if (IS_ERR(kvb_addr)) {
>  			ret = PTR_ERR(kvb_addr);
> -			goto done;
> +			goto free_cmd;
>  		}
>  		cmdbuf->vb_addr = kvb_addr;
>  	}
> @@ -1013,13 +1013,13 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  					  GFP_KERNEL);
>  		if (kbox_addr == NULL) {
>  			ret = -ENOMEM;
> -			goto done;
> +			goto free_vb;
>  		}
>  
>  		if (copy_from_user(kbox_addr, cmdbuf->box_addr,
>  				       cmdbuf->nbox * sizeof(struct drm_clip_rect))) {
>  			ret = -EFAULT;
> -			goto done;
> +			goto free_vb;
>  		}
>  	cmdbuf->box_addr = kbox_addr;
>  	}
> @@ -1052,7 +1052,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  					  "beyond end of command buffer\n");
>  				DMA_FLUSH();
>  				ret = -EINVAL;
> -				goto done;
> +				goto free_box;
>  			}
>  			/* fall through */
>  		case SAVAGE_CMD_DMA_PRIM:
> @@ -1071,7 +1071,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  				      cmdbuf->vb_stride,
>  				      cmdbuf->nbox, cmdbuf->box_addr);
>  				if (ret != 0)
> -					goto done;
> +					goto free_box;
>  				first_draw_cmd = NULL;
>  			}
>  		}
> @@ -1086,7 +1086,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  					  "beyond end of command buffer\n");
>  				DMA_FLUSH();
>  				ret = -EINVAL;
> -				goto done;
> +				goto free_box;
>  			}
>  			ret = savage_dispatch_state(dev_priv, &cmd_header,
>  				(const uint32_t *)cmdbuf->cmd_addr);
> @@ -1099,7 +1099,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  					  "beyond end of command buffer\n");
>  				DMA_FLUSH();
>  				ret = -EINVAL;
> -				goto done;
> +				goto free_box;
>  			}
>  			ret = savage_dispatch_clear(dev_priv, &cmd_header,
>  						    cmdbuf->cmd_addr,
> @@ -1117,12 +1117,12 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  				  cmd_header.cmd.cmd);
>  			DMA_FLUSH();
>  			ret = -EINVAL;
> -			goto done;
> +			goto free_box;
>  		}
>  
>  		if (ret != 0) {
>  			DMA_FLUSH();
> -			goto done;
> +			goto free_box;
>  		}
>  	}
>  
> @@ -1133,7 +1133,7 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  			cmdbuf->nbox, cmdbuf->box_addr);
>  		if (ret != 0) {
>  			DMA_FLUSH();
> -			goto done;
> +			goto free_box;
>  		}
>  	}
>  
> @@ -1147,11 +1147,11 @@ int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
>  		savage_freelist_put(dev, dmabuf);
>  	}
>  
> -done:
> -	/* If we didn't need to allocate them, these'll be NULL */
> -	kfree(kcmd_addr);
> -	kfree(kvb_addr);
> +free_box:
>  	kfree(kbox_addr);
> -
> +free_vb:
> +	kfree(kvb_addr);
> +free_cmd:
> +	kfree(kcmd_addr);
>  	return ret;
>  }
> -- 
> 2.9.3
>
SF Markus Elfring Oct. 12, 2016, 12:04 p.m. UTC | #2
>> Date: Thu, 18 Aug 2016 21:28:58 +0200
>>
>> The kfree() function was called in a few cases by the
>> savage_bci_cmdbuf() function during error handling
>> even if a passed variable contained a null pointer.
>>
>> Adjust jump targets according to the Linux coding style convention.
>>
>> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> 
> Not sure this is worth it, I'll pass. Patch 1 merged.

Unfortunately, it seems that this selection of only one update step
from this small patch series has got unwanted consequences.

Will the update suggestion “[patch] drm/savage: dereferencing an error pointer”
by Dan Carpenter (from today) trigger further software development discussions?

https://patchwork.kernel.org/patch/9372127/
https://lkml.kernel.org/r/<20161012062227.GU12841@mwanda>


Will an update step like “[PATCH 2/2] GPU-DRM-Savage: Less function calls in
savage_bci_cmdbuf() after error detection” (from 2016-08-18) become worth
for related consideratons once more?

https://patchwork.kernel.org/patch/9289183/
https://lkml.kernel.org/r/<c97563c0-d463-8b15-5956-26d93641a54f@users.sourceforge.net>

Regards,
Markus

Patch
diff mbox series

diff --git a/drivers/gpu/drm/savage/savage_state.c b/drivers/gpu/drm/savage/savage_state.c
index 3dc0d8f..5b484aa 100644
--- a/drivers/gpu/drm/savage/savage_state.c
+++ b/drivers/gpu/drm/savage/savage_state.c
@@ -1004,7 +1004,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 		kvb_addr = memdup_user(cmdbuf->vb_addr, cmdbuf->vb_size);
 		if (IS_ERR(kvb_addr)) {
 			ret = PTR_ERR(kvb_addr);
-			goto done;
+			goto free_cmd;
 		}
 		cmdbuf->vb_addr = kvb_addr;
 	}
@@ -1013,13 +1013,13 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 					  GFP_KERNEL);
 		if (kbox_addr == NULL) {
 			ret = -ENOMEM;
-			goto done;
+			goto free_vb;
 		}
 
 		if (copy_from_user(kbox_addr, cmdbuf->box_addr,
 				       cmdbuf->nbox * sizeof(struct drm_clip_rect))) {
 			ret = -EFAULT;
-			goto done;
+			goto free_vb;
 		}
 	cmdbuf->box_addr = kbox_addr;
 	}
@@ -1052,7 +1052,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 					  "beyond end of command buffer\n");
 				DMA_FLUSH();
 				ret = -EINVAL;
-				goto done;
+				goto free_box;
 			}
 			/* fall through */
 		case SAVAGE_CMD_DMA_PRIM:
@@ -1071,7 +1071,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 				      cmdbuf->vb_stride,
 				      cmdbuf->nbox, cmdbuf->box_addr);
 				if (ret != 0)
-					goto done;
+					goto free_box;
 				first_draw_cmd = NULL;
 			}
 		}
@@ -1086,7 +1086,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 					  "beyond end of command buffer\n");
 				DMA_FLUSH();
 				ret = -EINVAL;
-				goto done;
+				goto free_box;
 			}
 			ret = savage_dispatch_state(dev_priv, &cmd_header,
 				(const uint32_t *)cmdbuf->cmd_addr);
@@ -1099,7 +1099,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 					  "beyond end of command buffer\n");
 				DMA_FLUSH();
 				ret = -EINVAL;
-				goto done;
+				goto free_box;
 			}
 			ret = savage_dispatch_clear(dev_priv, &cmd_header,
 						    cmdbuf->cmd_addr,
@@ -1117,12 +1117,12 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 				  cmd_header.cmd.cmd);
 			DMA_FLUSH();
 			ret = -EINVAL;
-			goto done;
+			goto free_box;
 		}
 
 		if (ret != 0) {
 			DMA_FLUSH();
-			goto done;
+			goto free_box;
 		}
 	}
 
@@ -1133,7 +1133,7 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 			cmdbuf->nbox, cmdbuf->box_addr);
 		if (ret != 0) {
 			DMA_FLUSH();
-			goto done;
+			goto free_box;
 		}
 	}
 
@@ -1147,11 +1147,11 @@  int savage_bci_cmdbuf(struct drm_device *dev, void *data, struct drm_file *file_
 		savage_freelist_put(dev, dmabuf);
 	}
 
-done:
-	/* If we didn't need to allocate them, these'll be NULL */
-	kfree(kcmd_addr);
-	kfree(kvb_addr);
+free_box:
 	kfree(kbox_addr);
-
+free_vb:
+	kfree(kvb_addr);
+free_cmd:
+	kfree(kcmd_addr);
 	return ret;
 }