[U-Boot] [PATCH v3 01/10] Add getenv_ulong() to read an integer from an environment variable
Simon Glass
sjg at chromium.org
Sat Oct 15 01:27:22 CEST 2011
Hi Wolfgang,
On Fri, Oct 14, 2011 at 2:42 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1318626284-11161-1-git-send-email-sjg at chromium.org> you wrote:
>> This is not an uncommon operation in U-Boot, so let's put it in a common
>> function.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
> ...
>> +ulong getenv_ulong(const char *name, int base, ulong default_val)
>> +{
>> + char buff[20];
>> + const char *str = NULL;
>> +
>> + /*
>> + * Prior to the import of the environment into the hashtable we
>> + * should not call getenv()
>> + */
>> + if (gd->flags & GD_FLG_ENV_READY)
>> + str = getenv(name);
>> + else if (getenv_f(name, buff, sizeof(buff)) > 0)
>> + str = buff;
>> + return str ? simple_strtoul(str, NULL, base) : default_val;
>> +}
>
> Sorry, I just changed my mind.
>
> The issue with using getenv() before relocation is that it uses just a
> tiny buffer (usually 32 bytes) in the global data structure to store
> the result, which is often not sufficient for user provided data (some
> boards have hwconfig strings that are _much_ longer than that, and
> only the caller knows what to expect).
>
> It's only now that I realize that we are dealing with int / long
> values here only, so the length of the expected strings is indeed
> limited - actually the buffer you provide here is way smaller that
> what getenv() uses.
>
> Can we please switch back to the previous version, but insert a
> comment that explains why getenv_f() is not needed in this specific
> case?
OK I have done that and sent version 4 of that patch.
>
> Thanks, and apologies for causing additional efforts.
No problem.
Regards,
Simon
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> Status quo. Latin for "the mess we're in."
>
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