[PATCH] drivers/video/carminefb.c: improve error handling

From: Julia Lawall
Date: Sun Jan 02 2011 - 09:28:00 EST


From: Julia Lawall <julia@xxxxxxx>

This code had an error handling goto to the wrong place, a misplaced
release_mem_region, and a duplicated release_mem_region.

The semantic match that finds the double release_mem_region is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
expression e1,e2,e3;
position p1,p2,p3;
@@
release_mem_region@p1(e1, e2)@p3;
... when != request_mem_region(e1,e2,e3)
release_mem_region(e1, e2)@p2;

@@
expression e <= r.e1,e3;
expression r.e1,e2;
position r.p1,r.p2,r.p3,p!=r.p1;
@@
*release_mem_region(e1, e2)@p3;
... when != e = e3
*release_mem_region@p(e1, e2)@p2;// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
diff --git a/drivers/video/carminefb.c b/drivers/video/carminefb.c
index 6b19136..caaa27d 100644
--- a/drivers/video/carminefb.c
+++ b/drivers/video/carminefb.c
@@ -654,7 +654,7 @@ static int __devinit carminefb_probe(struct pci_dev *dev,
printk(KERN_ERR "carminefb: Memory bar is only %d bytes, %d "
"are required.", carminefb_fix.smem_len,
CARMINE_TOTAL_DIPLAY_MEM);
- goto err_free_reg_mmio;
+ goto err_unmap_vregs;
}

if (!request_mem_region(carminefb_fix.smem_start,
@@ -667,8 +667,6 @@ static int __devinit carminefb_probe(struct pci_dev *dev,
carminefb_fix.smem_len);
if (!hw->screen_mem) {
printk(KERN_ERR "carmine: Can't ioremap smem area.\n");
- release_mem_region(carminefb_fix.smem_start,
- carminefb_fix.smem_len);
goto err_reg_smem;
}

@@ -710,7 +708,7 @@ err_deinit_hw:
err_unmap_screen:
iounmap(hw->screen_mem);
err_reg_smem:
- release_mem_region(carminefb_fix.mmio_start, carminefb_fix.mmio_len);
+ release_mem_region(carminefb_fix.smem_start, carminefb_fix.smem_len);
err_unmap_vregs:
iounmap(hw->v_regs);
err_free_reg_mmio:
--
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