linux-kernel - Re: memparse(), simple

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <38b2ab8a0702200019q22bbc1b6ma0ab2771e152c288@mail.gmail.com>
Date:	Tue, 20 Feb 2007 09:19:31 +0100
From:	"Francis Moreau" <francis.moro@...il.com>
To:	"Avi Kivity" <avi@...o.co.il>
Cc:	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: memparse(), simple_strtoul() prototypes...

On 2/19/07, Avi Kivity <avi@...o.co.il> wrote:
> Francis Moreau wrote:
> >> > unsigned long simple_strtoul(const char *cp, char **endp,unsigned
> >> int base)
> >
> > hm, I don't get your point. I understand why we cast 'cp' into a (char
> > *) but that's not my point. My point is why aren't all function
> > parameters are not const ?
> >
>
> 'cp' can be passed as const, because simple_strtoul() does not modify
> it. 'endp' cannot be passed as const, because simple_strtoul() cannot
> know whether the caller would want to modify the string or not.
>
> Whichever way it is written, it is broken.  If changed to 'const', it
> would preclude the caller from modifying the string if one has a
> non-const string.  As written, it can silently convert a const string to
> a non-const string.  However, as written it is (a) standard conforming,
> and (b) more useful.
>

ok I think I finally got it and I agree that both ways are broken.

Maybe changing simple_strtoul() prototype as follow would be better ?

int simple_strtoul(const char *cp,  unsigned long *value, unsigned base)

the function would return the number of parsed char, and 'value' would
be the result.
-- 
Francis
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/