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From: Milton Miller <miltonm@bga.com>
Subject: Re: [PATCH 09/61] bootwrapper: Add dt_is_compatible().
Date: Wed, 18 Jul 2007 11:20:41 -0500
To: Scott Wood <scottwood@freescale.com>
Cc: ppcdev <linuxppc-dev@ozlabs.org>, Paul Mackerras <paulus@samba.org>,
	David Gibson <david@gibson.dropbear.id.au>
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On Wed Jul 18 11:33:06 EST 2007, Scott Wood wrote:
> +int dt_is_compatible(void *node, const char *compat)
> +{
> +       char *buf = (char *)prop_buf;
> +       int compat_len = strlen(compat);
> +       int len, pos;
> +
> +       len = getprop(node, "compatible", buf, MAX_PROP_LEN);
> +       if (len < 0)
> +               return 0;
> +
> +       for (pos = 0; pos + compat_len < len; pos++) {
> +               if (!strcmp(buf + pos, compat))
> +                       return 1;
> +
> +               while (buf[pos] && pos + compat_len < len)
> +                       pos++;

This is buggy: if you are searching for "ns16550" and the compatable is 
"fsl,1234\0commons16550" this code will incorrectly says its 
compatable.

Comparing pos < len instead will do the right thing, at the cost of a 
few iterations of the loop.

> +       }
> +
> +       return 0;

milton