* [PATCH] arch/arm/mach-pxa: avoid NULL dereference in error handling code
2010-03-21 20:48 [PATCH] arch/arm/mach-pxa: avoid NULL dereference in error handling code Julia Lawall
@ 2010-03-22 8:19 ` Eric Miao
0 siblings, 0 replies; 2+ messages in thread
From: Eric Miao @ 2010-03-22 8:19 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Mar 22, 2010 at 4:48 AM, Julia Lawall <julia@diku.dk> wrote:
> From: Julia Lawall <julia@diku.dk>
>
> The assignments of res to the results of the two calls to
> platform_get_resource make it impossible to use res in the error handling
> code in the arguments to release_mem_region.
>
Nice catch, I've yet made a small change to move the block of getting
dma resource earlier so to avoid introducing another variable pres.
> At the same time, code of the form res->end - res->start + 1 is converted
> to use resource_size.
>
OK, I've separated this into an individual patch with the above one,
rebased against my 'ssp_cleanup' branch as follows (note: the ssp.c
has been moved to plat-pxa for code sharing):
=====================================================
commit 97be6e52dc0aabaea07222bd0486e3b2df3e1baa
Author: Julia Lawall <julia@diku.dk>
Date: Mon Mar 22 16:11:55 2010 +0800
[ARM] pxa: avoid NULL dereferencing in error handling of ssp.c
The assignments of res to the results of the two calls to
platform_get_resource make it impossible to use res in the error handling
code in the arguments to release_mem_region.
The semantic match that finds the former problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression E, E1;
identifier f;
statement S1,S3;
iterator iter;
@@
if ((E == NULL && ...) || ...)
{
... when != false ((E == NULL && ...) || ...)
when != true ((E != NULL && ...) || ...)
when != iter(E,...) S1
when != E = E1
(
sizeof(E->f)
|
* E->f
)
... when any
return ...;
}
else S3
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c
index cfebcd8..3bf704d 100644
--- a/arch/arm/plat-pxa/ssp.c
+++ b/arch/arm/plat-pxa/ssp.c
@@ -92,6 +92,22 @@ static int __devinit ssp_probe(struct platform_device *pdev)
goto err_free;
}
+ res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
+ ret = -ENODEV;
+ goto err_free_clk;
+ }
+ ssp->drcmr_rx = res->start;
+
+ res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
+ ret = -ENODEV;
+ goto err_free_clk;
+ }
+ ssp->drcmr_tx = res->start;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
dev_err(&pdev->dev, "no memory resource defined\n");
@@ -123,22 +139,6 @@ static int __devinit ssp_probe(struct
platform_device *pdev)
goto err_free_io;
}
- res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
- if (res == NULL) {
- dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
- ret = -ENODEV;
- goto err_free_io;
- }
- ssp->drcmr_rx = res->start;
-
- res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
- if (res == NULL) {
- dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
- ret = -ENODEV;
- goto err_free_io;
- }
- ssp->drcmr_tx = res->start;
-
/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
* starts from 0, do a translation here
*/
===============================================================================
commit 00921f0d5f21f213b8407d348b53fdce4ad383bd
Author: Julia Lawall <julia@diku.dk>
Date: Mon Mar 22 16:16:24 2010 +0800
[ARM] pxa: use resource_size() in ssp.c
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c
index 3bf704d..52c07cc 100644
--- a/arch/arm/plat-pxa/ssp.c
+++ b/arch/arm/plat-pxa/ssp.c
@@ -115,7 +115,7 @@ static int __devinit ssp_probe(struct platform_device *pdev)
goto err_free_clk;
}
- res = request_mem_region(res->start, res->end - res->start + 1,
+ res = request_mem_region(res->start, resource_size(res),
pdev->name);
if (res == NULL) {
dev_err(&pdev->dev, "failed to request memory resource\n");
@@ -125,7 +125,7 @@ static int __devinit ssp_probe(struct platform_device *pdev)
ssp->phys_base = res->start;
- ssp->mmio_base = ioremap(res->start, res->end - res->start + 1);
+ ssp->mmio_base = ioremap(res->start, resource_size(res));
if (ssp->mmio_base == NULL) {
dev_err(&pdev->dev, "failed to ioremap() registers\n");
ret = -ENODEV;
@@ -156,7 +156,7 @@ static int __devinit ssp_probe(struct platform_device *pdev)
err_free_io:
iounmap(ssp->mmio_base);
err_free_mem:
- release_mem_region(res->start, res->end - res->start + 1);
+ release_mem_region(res->start, resource_size(res));
err_free_clk:
clk_put(ssp->clk);
err_free:
@@ -176,7 +176,7 @@ static int __devexit ssp_remove(struct
platform_device *pdev)
iounmap(ssp->mmio_base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- release_mem_region(res->start, res->end - res->start + 1);
+ release_mem_region(res->start, resource_size(res));
clk_put(ssp->clk);
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