From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Syed Nayyar Waris <syednwaris@gmail.com>,
Rikard Falkeborn <rikard.falkeborn@gmail.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Kees Cook <keescook@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Linus Walleij <linus.walleij@linaro.org>,
Andrew Morton <akpm@linux-foundation.org>,
William Breathitt Gray <vilhelm.gray@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
Linux-Arch <linux-arch@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 1/4] bitops: Introduce the the for_each_set_clump macro
Date: Sun, 31 May 2020 14:00:45 +0300 [thread overview]
Message-ID: <CAHp75Vdxa1_ANBLEOB6g25x3O0V5h3yjZve8qpz-xkisD3KTLg@mail.gmail.com> (raw)
In-Reply-To: <CACG_h5p1UpLRoA+ubE4NTFQEvg-oT6TFmsLXXTAtBvzN9z3iPg@mail.gmail.com>
On Sun, May 31, 2020 at 4:11 AM Syed Nayyar Waris <syednwaris@gmail.com> wrote:
> On Sat, May 30, 2020 at 2:50 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Sat, May 30, 2020 at 11:45 AM Syed Nayyar Waris <syednwaris@gmail.com> wrote:
> > > On Sat, May 30, 2020 at 3:49 AM Andy Shevchenko
> > > <andy.shevchenko@gmail.com> wrote:
...
> #if (l) == 0
> #define GENMASK_INPUT_CHECK(h, l) 0
> #elif
> #define GENMASK_INPUT_CHECK(h, l) \
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> __builtin_constant_p((l) > (h)), (l) > (h), 0)))
> #endif
>
> I have verified that this works. Basically this just avoids the sanity
> check when the 'lower' bound 'l' is zero. Let me know if it looks
> fine.
Unfortunately, it's not enough. We need to take care about the following cases
1) h or l negative;
2) h == 0, if l == 0, I dunno what is this. it's basically either 0 or warning;
3) l == 0;
4) h and l > 0.
Now, on top of that (since it's a macro) we have to keep in mind that
h and l can be signed and / or unsigned types.
And macro shall work for all 4 cases (by type signedess).
> Regarding min, max macro that you suggested I am also looking further into it.
Since this has been introduced in v5.7 and not only your code is
affected by this I think we need to ping original author either to fix
or revert.
So, I Cc'ed to the author and reviewers, because they probably know
better why that had been done in the first place and breaking existing
code.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2020-05-31 11:01 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-24 5:00 [PATCH v7 0/4] Introduce the for_each_set_clump macro Syed Nayyar Waris
2020-05-24 5:01 ` [PATCH v7 1/4] bitops: Introduce the " Syed Nayyar Waris
2020-05-24 14:44 ` kbuild test robot
2020-05-29 18:08 ` Syed Nayyar Waris
2020-05-29 18:38 ` Andy Shevchenko
2020-05-29 20:02 ` Syed Nayyar Waris
2020-05-29 21:31 ` William Breathitt Gray
2020-05-29 21:53 ` Syed Nayyar Waris
2020-05-29 21:42 ` Andy Shevchenko
2020-05-29 22:07 ` Andy Shevchenko
2020-05-29 22:11 ` Syed Nayyar Waris
2020-05-29 22:19 ` Andy Shevchenko
2020-05-30 8:45 ` Syed Nayyar Waris
2020-05-30 9:20 ` Andy Shevchenko
2020-05-31 1:11 ` Syed Nayyar Waris
2020-05-31 11:00 ` Andy Shevchenko [this message]
2020-05-31 22:37 ` Rikard Falkeborn
2020-06-01 0:31 ` Syed Nayyar Waris
2020-06-01 8:33 ` Andy Shevchenko
2020-06-02 19:01 ` Rikard Falkeborn
2020-06-03 8:49 ` Andy Shevchenko
2020-06-03 21:53 ` Rikard Falkeborn
2020-06-03 21:58 ` Andy Shevchenko
2020-06-03 21:59 ` Andy Shevchenko
2020-06-03 22:02 ` [PATCH] linux/bits.h: fix unsigned less than zero warnings Rikard Falkeborn
2020-06-04 6:41 ` Andy Shevchenko
2020-06-04 16:49 ` Joe Perches
2020-06-04 23:30 ` Rikard Falkeborn
2020-06-07 20:34 ` [PATCH v2 1/2] " Rikard Falkeborn
2020-06-07 20:34 ` [PATCH v2 2/2] bits: Add tests of GENMASK Rikard Falkeborn
2020-06-08 7:33 ` Geert Uytterhoeven
2020-06-08 18:42 ` Rikard Falkeborn
2020-06-08 22:18 ` [PATCH v3 1/2] linux/bits.h: fix unsigned less than zero warnings Rikard Falkeborn
2020-06-08 22:18 ` [PATCH v3 2/2] bits: Add tests of GENMASK Rikard Falkeborn
2020-06-09 14:11 ` Andy Shevchenko
2020-06-21 4:36 ` Andrew Morton
2020-06-21 5:42 ` [PATCH v4 1/2] linux/bits.h: fix unsigned less than zero warnings Rikard Falkeborn
2020-06-21 5:42 ` [PATCH v4 2/2] bits: Add tests of GENMASK Rikard Falkeborn
2021-04-22 19:40 ` Nico Pache
2021-04-22 21:30 ` Nico Pache
2020-07-09 12:30 ` [PATCH v4 1/2] linux/bits.h: fix unsigned less than zero warnings Herbert Xu
2020-07-09 18:13 ` Linus Torvalds
2020-07-10 6:38 ` Herbert Xu
2020-06-15 19:52 ` [PATCH v3 " Emil Velikov
2020-06-08 8:08 ` [PATCH v2 2/2] bits: Add tests of GENMASK Andy Shevchenko
2020-06-08 8:08 ` Andy Shevchenko
2020-06-08 18:44 ` Rikard Falkeborn
2020-06-08 11:09 ` [PATCH v2 1/2] linux/bits.h: fix unsigned less than zero warnings Andy Shevchenko
2020-05-24 5:04 ` [PATCH v7 2/4] lib/test_bitmap.c: Add for_each_set_clump test cases Syed Nayyar Waris
2020-05-30 19:20 ` kbuild test robot
2020-06-04 20:42 ` Syed Nayyar Waris
2020-06-05 12:24 ` Andy Shevchenko
2020-06-06 23:15 ` Syed Nayyar Waris
2020-06-08 13:18 ` Andy Shevchenko
2020-06-10 5:38 ` Rong Chen
2020-05-24 5:05 ` [PATCH v7 3/4] gpio: thunderx: Utilize for_each_set_clump macro Syed Nayyar Waris
2020-05-24 5:06 ` [PATCH v7 4/4] gpio: xilinx: " Syed Nayyar Waris
2020-05-25 9:36 ` [PATCH v7 0/4] Introduce the " Bartosz Golaszewski
2020-06-15 12:46 ` Syed Nayyar Waris
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAHp75Vdxa1_ANBLEOB6g25x3O0V5h3yjZve8qpz-xkisD3KTLg@mail.gmail.com \
--to=andy.shevchenko@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=arnd@arndb.de \
--cc=keescook@chromium.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rikard.falkeborn@gmail.com \
--cc=syednwaris@gmail.com \
--cc=vilhelm.gray@gmail.com \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).