drivers/video/bf537-lq035.c: Add missing IS_ERR test

lcd_device_register may return ERR_PTR, so a check is added for this value
before the dereference.  All of the other changes reorganize the error
handling code in this function to avoid duplicating all of it in the added
case.

In the original code, in one case, the global variable fb_buffer was set to
NULL in error code that appears after this variable is initialized.  This
is done now in all error handling code that has this property.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier f;
@@
f(...) { ... return ERR_PTR(...); }

@@
identifier r.f, fld;
expression x;
statement S1,S2;
@@
 x = f(...)
 ... when != IS_ERR(x)
(
 if (IS_ERR(x) ||...) S1 else S2
|
*x->fld
)
// </smpl>

Signed-off-by: Julia Lawall <redacted>

---
 drivers/video/bf537-lq035.c |   58 +++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 25 deletions(-)

diff --git a/drivers/video/bf537-lq035.c b/drivers/video/bf537-lq035.c
index 18c5078..47c21fb 100644
--- a/drivers/video/bf537-lq035.c
+++ b/drivers/video/bf537-lq035.c

@@ -696,6 +696,7 @@ static int __devinit bfin_lq035_probe(struct platform_device *pdev)
 {
 	struct backlight_properties props;
 	dma_addr_t dma_handle;
+	int ret;
 
 	if (request_dma(CH_PPI, KBUILD_MODNAME)) {
 		pr_err("couldn't request PPI DMA\n");

@@ -704,17 +705,16 @@ static int __devinit bfin_lq035_probe(struct platform_device *pdev)
 
 	if (request_ports()) {
 		pr_err("couldn't request gpio port\n");
-		free_dma(CH_PPI);
-		return -EFAULT;
+		ret = -EFAULT;
+		goto out_ports;
 	}
 
 	fb_buffer = dma_alloc_coherent(NULL, TOTAL_VIDEO_MEM_SIZE,
 				       &dma_handle, GFP_KERNEL);
 	if (fb_buffer = NULL) {
 		pr_err("couldn't allocate dma buffer\n");
-		free_dma(CH_PPI);
-		free_ports();
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_dma_coherent;
 	}
 
 	if (L1_DATA_A_LENGTH)

@@ -725,10 +725,8 @@ static int __devinit bfin_lq035_probe(struct platform_device *pdev)
 
 	if (dma_desc_table = NULL) {
 		pr_err("couldn't allocate dma descriptor\n");
-		free_dma(CH_PPI);
-		free_ports();
-		dma_free_coherent(NULL, TOTAL_VIDEO_MEM_SIZE, fb_buffer, 0);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_table;
 	}
 
 	bfin_lq035_fb.screen_base = (void *)fb_buffer;

@@ -771,31 +769,21 @@ static int __devinit bfin_lq035_probe(struct platform_device *pdev)
 	bfin_lq035_fb.pseudo_palette = kzalloc(sizeof(u32) * 16, GFP_KERNEL);
 	if (bfin_lq035_fb.pseudo_palette = NULL) {
 		pr_err("failed to allocate pseudo_palette\n");
-		free_dma(CH_PPI);
-		free_ports();
-		dma_free_coherent(NULL, TOTAL_VIDEO_MEM_SIZE, fb_buffer, 0);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_palette;
 	}
 
 	if (fb_alloc_cmap(&bfin_lq035_fb.cmap, NBR_PALETTE, 0) < 0) {
 		pr_err("failed to allocate colormap (%d entries)\n",
 			NBR_PALETTE);
-		free_dma(CH_PPI);
-		free_ports();
-		dma_free_coherent(NULL, TOTAL_VIDEO_MEM_SIZE, fb_buffer, 0);
-		kfree(bfin_lq035_fb.pseudo_palette);
-		return -EFAULT;
+		ret = -EFAULT;
+		goto out_cmap;
 	}
 
 	if (register_framebuffer(&bfin_lq035_fb) < 0) {
 		pr_err("unable to register framebuffer\n");
-		free_dma(CH_PPI);
-		free_ports();
-		dma_free_coherent(NULL, TOTAL_VIDEO_MEM_SIZE, fb_buffer, 0);
-		fb_buffer = NULL;
-		kfree(bfin_lq035_fb.pseudo_palette);
-		fb_dealloc_cmap(&bfin_lq035_fb.cmap);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_reg;
 	}
 
 	i2c_add_driver(&ad5280_driver);

@@ -807,11 +795,31 @@ static int __devinit bfin_lq035_probe(struct platform_device *pdev)
 
 	lcd_dev = lcd_device_register(KBUILD_MODNAME, &pdev->dev, NULL,
 				      &bfin_lcd_ops);
+	if (IS_ERR(lcd_dev)) {
+		pr_err("unable to register lcd\n");
+		ret = PTR_ERR(lcd_dev);
+		goto out_lcd;
+	}
 	lcd_dev->props.max_contrast = 255,
 
 	pr_info("initialized");
 
 	return 0;
+out_lcd:
+	unregister_framebuffer(&bfin_lq035_fb);
+out_reg:
+	fb_dealloc_cmap(&bfin_lq035_fb.cmap);
+out_cmap:
+	kfree(bfin_lq035_fb.pseudo_palette);
+out_palette:
+out_table:
+	dma_free_coherent(NULL, TOTAL_VIDEO_MEM_SIZE, fb_buffer, 0);
+	fb_buffer = NULL;
+out_dma_coherent:
+	free_ports();
+out_ports:
+	free_dma(CH_PPI);
+	return ret;
 }
 
 static int __devexit bfin_lq035_remove(struct platform_device *pdev)

On Monday, January 24, 2011 14:55:21 Julia Lawall wrote:

lcd_device_register may return ERR_PTR, so a check is added for this value
before the dereference.  All of the other changes reorganize the error
handling code in this function to avoid duplicating all of it in the added
case.

In the original code, in one case, the global variable fb_buffer was set to
NULL in error code that appears after this variable is initialized.  This
is done now in all error handling code that has this property.

Acked-by: Mike Frysinger <redacted>
-mike

On Mon, Jan 24, 2011 at 03:43:17PM -0500, Mike Frysinger wrote:

On Monday, January 24, 2011 14:55:21 Julia Lawall wrote:

quoted

lcd_device_register may return ERR_PTR, so a check is added for this value
before the dereference.  All of the other changes reorganize the error
handling code in this function to avoid duplicating all of it in the added
case.

In the original code, in one case, the global variable fb_buffer was set to
NULL in error code that appears after this variable is initialized.  This
is done now in all error handling code that has this property.

Acked-by: Mike Frysinger <redacted>

Applied, thanks.

Julia Lawall wrote on 2011-01-24:

lcd_device_register may return ERR_PTR, so a check is added for this
value before the dereference.  All of the other changes reorganize the
error handling code in this function to avoid duplicating all of it in
the added case.

In the original code, in one case, the global variable fb_buffer was
set to NULL in error code that appears after this variable is
initialized.  This is done now in all error handling code that has
this property.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier f;
@@
f(...) { ... return ERR_PTR(...); }

@@
identifier r.f, fld;
expression x;
statement S1,S2;
@@
 x = f(...) ... when != IS_ERR(x) ( if (IS_ERR(x) ||...) S1 else S2
|
*x->fld
)
// </smpl>

Signed-off-by: Julia Lawall <redacted>

Looks good to me.

Acked-by: "Hennerich, Michael" <Michael.Hennerich@analog.com>

80 more quoted lines

Greetings,
Michael

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