linux-mips
[Top] [All Lists]

Re: [PATCH] of: of_mdio: Fix some endianness problems.

To: David Daney <ddaney@caviumnetworks.com>
Subject: Re: [PATCH] of: of_mdio: Fix some endianness problems.
From: Grant Likely <grant.likely@secretlab.ca>
Date: Sat, 30 Oct 2010 07:32:37 +0100
Cc: linux-mips@linux-mips.org, ralf@linux-mips.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Jeremy Kerr <jeremy.kerr@canonical.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Dan Carpenter <error27@gmail.com>, Greg Kroah-Hartman <gregkh@suse.de>
In-reply-to: <1288227827-5447-1-git-send-email-ddaney@caviumnetworks.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <1288227827-5447-1-git-send-email-ddaney@caviumnetworks.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.5.20 (2009-06-14)
On Wed, Oct 27, 2010 at 06:03:47PM -0700, David Daney wrote:
> In of_mdiobus_register(), the __be32 *addr variable is dereferenced.
> This will not work on little-endian targets.  Also since it is
> unsigned, checking for less than zero is redundant.
> 
> Fix these two issues.
> 
> Signed-off-by: David Daney <ddaney@caviumnetworks.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Jeremy Kerr <jeremy.kerr@canonical.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Dan Carpenter <error27@gmail.com>
> Cc: Greg Kroah-Hartman <gregkh@suse.de>
> ---
>  drivers/of/of_mdio.c |   23 ++++++++++++++---------
>  1 files changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index 1fce00e..b370306 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -52,27 +52,32 @@ int of_mdiobus_register(struct mii_bus *mdio, struct 
> device_node *np)
>  
>       /* Loop over the child nodes and register a phy_device for each one */
>       for_each_child_of_node(np, child) {
> -             const __be32 *addr;
> +             const __be32 *paddr;
> +             u32 addr;
>               int len;
>  
>               /* A PHY must have a reg property in the range [0-31] */
> -             addr = of_get_property(child, "reg", &len);
> -             if (!addr || len < sizeof(*addr) || *addr >= 32 || *addr < 0) {
> +             paddr = of_get_property(child, "reg", &len);
> +             if (!paddr || len < sizeof(*paddr)) {
> +addr_err:
>                       dev_err(&mdio->dev, "%s has invalid PHY address\n",
>                               child->full_name);
>                       continue;
>               }
> +             addr = be32_to_cpup(paddr);
> +             if (addr >= 32)
> +                     goto addr_err;

goto's are fine for jumping to the end of a function to unwind
allocations, but please don't use it in this manner.  The original
structure will actually work just fine if you do it thusly:

                if (!paddr || len < sizeof(*paddr) ||
                    *(addr = be32_to_cpup(paddr)) >= 32) {
                        dev_err(&mdio->dev, "%s has invalid PHY address\n",
                                child->full_name);
                        continue;
                }

Otherwise this patch looks good. After you've reworked and retested
I'll pick it up for 2.6.37 (or dave will).

g.


>  
>               if (mdio->irq) {
> -                     mdio->irq[*addr] = irq_of_parse_and_map(child, 0);
> -                     if (!mdio->irq[*addr])
> -                             mdio->irq[*addr] = PHY_POLL;
> +                     mdio->irq[addr] = irq_of_parse_and_map(child, 0);
> +                     if (!mdio->irq[addr])
> +                             mdio->irq[addr] = PHY_POLL;
>               }
>  
> -             phy = get_phy_device(mdio, be32_to_cpup(addr));
> +             phy = get_phy_device(mdio, addr);
>               if (!phy || IS_ERR(phy)) {
>                       dev_err(&mdio->dev, "error probing PHY at address %i\n",
> -                             *addr);
> +                             addr);
>                       continue;
>               }
>               phy_scan_fixups(phy);
> @@ -91,7 +96,7 @@ int of_mdiobus_register(struct mii_bus *mdio, struct 
> device_node *np)
>               }
>  
>               dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
> -                     child->name, *addr);
> +                     child->name, addr);
>       }
>  
>       return 0;
> -- 
> 1.7.2.3
> 

<Prev in Thread] Current Thread [Next in Thread>