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Date: Fri, 2 Nov 2012 09:01:56 -0500
From: Eric van Gyzen <eric@vangyzen.net>
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To: Alfred Perlstein <alfred@ixsystems.com>
Subject: Re: please review: patch to retain device name for dumpdev.
References: <50921B44.20400@ixsystems.com>
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Cc: mav@freebsd.org, hackers@freebsd.org
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On 11/01/2012 01:48, Alfred Perlstein wrote:
>  /* Registration of dumpers */
>  int
> -set_dumper(struct dumperinfo *di)
> +set_dumper(struct dumperinfo *di, const char *devname)
>  {
>
>      if (di == NULL) {
>          bzero(&dumper, sizeof dumper);
> +        dumpdevname[0] = '\0';
>          return (0);
>      }
>      if (dumper.dumper != NULL)
>          return (EBUSY);
>      dumper = *di;
> +    strlcpy(dumpdevname, devname, sizeof(dumpdevname));
> +    if (strlen(dumpdevname) != strlen(devname)) {

You can use the return value of strlcpy() to test for truncation, and 
save two strlen()s:

         if (strlcpy(...) >= sizeof(dst)) { /* truncated */ }

> + printf("set_dumper: device name truncated from '%s' -> '%s'\n",
> +            devname, dumpdevname);
> +    }
>      return (0);
>  }