linux-kernel - Re: [PATCH 3/8] lib: bitmap: fold nbits into region struct

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

Message-ID: <YBCHFrO3LS+Hztx/@smile.fi.intel.com>
Date:   Tue, 26 Jan 2021 23:18:14 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Paul Gortmaker <paul.gortmaker@...driver.com>
Cc:     linux-kernel@...r.kernel.org, lizefan@...wei.com, mingo@...nel.org,
        tglx@...utronix.de, josh@...htriplett.org, yury.norov@...il.com,
        peterz@...radead.org, paulmck@...nel.org, fweisbec@...il.com,
        linux@...musvillemoes.dk
Subject: Re: [PATCH 3/8] lib: bitmap: fold nbits into region struct

On Tue, Jan 26, 2021 at 11:16:25PM +0200, Andy Shevchenko wrote:
> On Tue, Jan 26, 2021 at 12:11:36PM -0500, Paul Gortmaker wrote:
> > This will reduce parameter passing and enable using nbits as part
> > of future dynamic region parameter parsing.

...

> >  	struct region r;
> >  	long ret;
> >  
> > -	bitmap_zero(maskp, nmaskbits);
> > +	r.nbits = nmaskbits;

Alternatively (though I personally don't prefer it) you can clarify in the
definition block the initial values.

	struct region r = { .nbist = nmaskbits };

> > +	bitmap_zero(maskp, r.nbits);
> 
> This sounds not right from style perspective.
> You have completely uninitialized r on stack, then you assign only one value
> for immediate use here and...
> 
> >  	while (buf) {
> >  		buf = bitmap_find_region(buf);
> > @@ -655,7 +656,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
> >  		if (ret)
> >  			return ret;
> >  
> > -		ret = bitmap_set_region(&r, maskp, nmaskbits);
> > +		ret = bitmap_set_region(&r, maskp);
> 
> ...hiding this fact here. Which I would expect that &r may be rewritten here.
> 
> I would leave these unchanged and simple assign the value in
> bitmap_set_region().

-- 
With Best Regards,
Andy Shevchenko