2013-05-10 08:17:34

by Wolfram Sang

Subject: [RFC 30/42] drivers/usb/host: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.

Signed-off-by: Wolfram Sang <[email protected]>
---
drivers/usb/host/ehci-atmel.c | 9 +--------
drivers/usb/host/ehci-mxc.c | 8 +-------
drivers/usb/host/ehci-platform.c | 6 +-----
drivers/usb/host/ehci-sh.c | 10 +---------
drivers/usb/host/ohci-nxp.c | 6 ------
drivers/usb/host/ohci-platform.c | 7 +------
6 files changed, 5 insertions(+), 41 deletions(-)

diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 6642009..62bf3e6 100644
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -101,17 +101,10 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
goto fail_create_hcd;
}

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev,
- "Found HC with no register addr. Check %s setup!\n",
- dev_name(&pdev->dev));
- retval = -ENODEV;
- goto fail_request_resource;
- }
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);

+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
retval = PTR_ERR(hcd->regs);
diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index c369767..04be939 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/drivers/usb/host/ehci-mxc.c
@@ -68,16 +68,10 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
if (!hcd)
return -ENOMEM;

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(dev, "Found HC with no register addr. Check setup!\n");
- ret = -ENODEV;
- goto err_alloc;
- }
-
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);

+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
ret = PTR_ERR(hcd->regs);
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index f47f259..9466aea 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -95,11 +95,6 @@ static int ehci_platform_probe(struct platform_device *dev)
dev_err(&dev->dev, "no irq provided");
return irq;
}
- res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
- if (!res_mem) {
- dev_err(&dev->dev, "no memory resource provided");
- return -ENXIO;
- }

if (pdata->power_on) {
err = pdata->power_on(dev);
@@ -117,6 +112,7 @@ static int ehci_platform_probe(struct platform_device *dev)
hcd->rsrc_start = res_mem->start;
hcd->rsrc_len = resource_size(res_mem);

+ res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
if (IS_ERR(hcd->regs)) {
err = PTR_ERR(hcd->regs);
diff --git a/drivers/usb/host/ehci-sh.c b/drivers/usb/host/ehci-sh.c
index b44d716..7b7809a 100644
--- a/drivers/usb/host/ehci-sh.c
+++ b/drivers/usb/host/ehci-sh.c
@@ -86,15 +86,6 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
if (usb_disabled())
return -ENODEV;

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev,
- "Found HC with no register addr. Check %s setup!\n",
- dev_name(&pdev->dev));
- ret = -ENODEV;
- goto fail_create_hcd;
- }
-
irq = platform_get_irq(pdev, 0);
if (irq <= 0) {
dev_err(&pdev->dev,
@@ -117,6 +108,7 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);

+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
ret = PTR_ERR(hcd->regs);
diff --git a/drivers/usb/host/ohci-nxp.c b/drivers/usb/host/ohci-nxp.c
index f4988fb..f303cb0 100644
--- a/drivers/usb/host/ohci-nxp.c
+++ b/drivers/usb/host/ohci-nxp.c
@@ -300,12 +300,6 @@ static int usb_hcd_nxp_probe(struct platform_device *pdev)
}

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "Failed to get MEM resource\n");
- ret = -ENOMEM;
- goto out8;
- }
-
hcd->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hcd->regs)) {
ret = PTR_ERR(hcd->regs);
diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index c3e7287..6656420 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -106,12 +106,6 @@ static int ohci_platform_probe(struct platform_device *dev)
return irq;
}

- res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
- if (!res_mem) {
- dev_err(&dev->dev, "no memory resource provided");
- return -ENXIO;
- }
-
if (pdata->power_on) {
err = pdata->power_on(dev);
if (err < 0)
@@ -128,6 +122,7 @@ static int ohci_platform_probe(struct platform_device *dev)
hcd->rsrc_start = res_mem->start;
hcd->rsrc_len = resource_size(res_mem);

+ res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
if (IS_ERR(hcd->regs)) {
err = PTR_ERR(hcd->regs);
--
1.7.10.4

2013-05-10 14:03:33

by Alan Stern

Subject: Re: [RFC 30/42] drivers/usb/host: don't check resource with devm_ioremap_resource

On Fri, 10 May 2013, Wolfram Sang wrote:

> devm_ioremap_resource does sanity checks on the given resource. No need to
> duplicate this in the driver.
>
> Signed-off-by: Wolfram Sang <[email protected]>
> ---
> drivers/usb/host/ehci-atmel.c | 9 +--------
> drivers/usb/host/ehci-mxc.c | 8 +-------
> drivers/usb/host/ehci-platform.c | 6 +-----
> drivers/usb/host/ehci-sh.c | 10 +---------
> drivers/usb/host/ohci-nxp.c | 6 ------
> drivers/usb/host/ohci-platform.c | 7 +------
> 6 files changed, 5 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> index 6642009..62bf3e6 100644
> --- a/drivers/usb/host/ehci-atmel.c
> +++ b/drivers/usb/host/ehci-atmel.c
> @@ -101,17 +101,10 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
> goto fail_create_hcd;
> }
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (!res) {
> - dev_err(&pdev->dev,
> - "Found HC with no register addr. Check %s setup!\n",
> - dev_name(&pdev->dev));
> - retval = -ENODEV;
> - goto fail_request_resource;
> - }
> hcd->rsrc_start = res->start;
> hcd->rsrc_len = resource_size(res);
>
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> hcd->regs = devm_ioremap_resource(&pdev->dev, res);

This isn't right. You are now dereferencing an uninitialized pointer
in the assignment to hcd->rsrc_start. The compiler won't like that.

Most of the other changes in this patch suffer from the same problem.

Alan Stern

2013-05-10 15:25:42

by Greg Kroah-Hartman

Subject: Re: [RFC 30/42] drivers/usb/host: don't check resource with devm_ioremap_resource

On Fri, May 10, 2013 at 10:17:15AM +0200, Wolfram Sang wrote:
> devm_ioremap_resource does sanity checks on the given resource. No need to
> duplicate this in the driver.
>
> Signed-off-by: Wolfram Sang <[email protected]>

As Alan pointed out, the majority of these are all wrong, please do NOT
push this patch to Linus.

thanks,

greg k-h

2013-05-10 17:58:50

by Wolfram Sang

Subject: Re: [RFC 30/42] drivers/usb/host: don't check resource with devm_ioremap_resource

On Fri, May 10, 2013 at 10:03:28AM -0400, Alan Stern wrote:
> On Fri, 10 May 2013, Wolfram Sang wrote:
>
> > devm_ioremap_resource does sanity checks on the given resource. No need to
> > duplicate this in the driver.
> >
> > Signed-off-by: Wolfram Sang <[email protected]>
> > ---
> > drivers/usb/host/ehci-atmel.c | 9 +--------
> > drivers/usb/host/ehci-mxc.c | 8 +-------
> > drivers/usb/host/ehci-platform.c | 6 +-----
> > drivers/usb/host/ehci-sh.c | 10 +---------
> > drivers/usb/host/ohci-nxp.c | 6 ------
> > drivers/usb/host/ohci-platform.c | 7 +------
> > 6 files changed, 5 insertions(+), 41 deletions(-)
> >
> > diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
> > index 6642009..62bf3e6 100644
> > --- a/drivers/usb/host/ehci-atmel.c
> > +++ b/drivers/usb/host/ehci-atmel.c
> > @@ -101,17 +101,10 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
> > goto fail_create_hcd;
> > }
> >
> > - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > - if (!res) {
> > - dev_err(&pdev->dev,
> > - "Found HC with no register addr. Check %s setup!\n",
> > - dev_name(&pdev->dev));
> > - retval = -ENODEV;
> > - goto fail_request_resource;
> > - }
> > hcd->rsrc_start = res->start;
> > hcd->rsrc_len = resource_size(res);
> >
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > hcd->regs = devm_ioremap_resource(&pdev->dev, res);
>
> This isn't right. You are now dereferencing an uninitialized pointer
> in the assignment to hcd->rsrc_start. The compiler won't like that.
>
> Most of the other changes in this patch suffer from the same problem.

I broke the detection of dereferencing and compile tested an unaffected
kernel. Thanks for pointing out. Will fix!