On Thu, Jan 28, 2021 at 8:11 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, Jan 28, 2021 at 10:19:47AM +0800, Yafang Shao wrote:
> > Currently the pGp only shows the names of page flags, rather than
> > the full information including section, node, zone, last cpupid and
> > kasan tag. While it is not easy to parse these information manually
> > because there're so many flavors. Let's interpret them in pGp as well.
> >
> > - Before the patch,
> > [ 6312.639698] ERR: Slab 0x000000006d1133b9 objects=33 used=3 fp=0x000000006d0779d1 flags=0x17ffffc0010200(slab|head)
> >
> > - After the patch,
> > [ 6315.235783] ERR: Slab 0x000000006d1133b9 objects=33 used=3 fp=0x000000006d0779d1 flags=0x17ffffc0010200(Node 0x0,Zone 0x2,Lastcpupid 0x1fffff,slab|head)
>
> > + int i;
> > +
> > + for (i = 0; i < sizeof(pfl) / sizeof(struct page_flags_layout) && buf < end; i++) {
>
> 'buf < end' is redundant.
>
Thanks for pointing this out.
> > + if (pfl[i].width == 0)
> > + continue;
> > +
> > + buf = string(buf, end, pfl[i].name, default_str_spec);
>
> > + if (buf >= end)
> > + break;
>
> Can you rather use usual patter, i.e.
>
> if (buf < end) {
> ...do something...
> }
> buf++; // or whatever increase should be done
>
> Moreover, number() and string() IIRC have the proper checks embedded into them.
>
I will take a look at the detail in these two functions.
> > + buf = number(buf, end, (flags >> pfl[i].shift) & pfl[i].mask,
> > + default_flag_spec);
>
> > + if (buf >= end)
> > + break;
> > + *buf = ',';
> > + buf++;
>
> Here is a very standard pattern can be used, see code around
>
> if (buf < end)
> *buf = ',';
> buf++;
>
> > + }
>
Thanks for the explanation.
I will change it as you suggested.
--
Thanks
Yafang
