From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Rikard Falkeborn <rikard.falkeborn@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
Linux-Arch <linux-arch@vger.kernel.org>,
Linux-SH <linux-sh@vger.kernel.org>,
Alexey Klimov <aklimov@redhat.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Arnd Bergmann <arnd@arndb.de>, David Sterba <dsterba@suse.com>,
Dennis Zhou <dennis@kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Jianpeng Ma <jianpeng.ma@intel.com>,
Joe Perches <joe@perches.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Rich Felker <dalias@libc.org>,
Stefano Brivio <sbrivio@redhat.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>
Subject: Re: [PATCH 11/12] tools: sync lib/find_bit implementation
Date: Mon, 10 May 2021 18:44:44 +0300 [thread overview]
Message-ID: <CAHp75Vea0Y_LfWC7LNDoDZqO4t+SVHV5HZMzErfyMPoBAjjk1g@mail.gmail.com> (raw)
In-Reply-To: <1ac7bbc2-45d9-26ed-0b33-bf382b8d858b@I-love.SAKURA.ne.jp>
+Cc: Rikard
On Mon, May 10, 2021 at 6:31 PM Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
>
> Commit eaae7841ba83bb42 ("tools: sync lib/find_bit implementation") broke
> build of 5.13-rc1 using gcc (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3).
>
> DESCEND objtool
> CC /usr/src/linux/tools/objtool/exec-cmd.o
> CC /usr/src/linux/tools/objtool/help.o
> CC /usr/src/linux/tools/objtool/pager.o
> CC /usr/src/linux/tools/objtool/parse-options.o
> CC /usr/src/linux/tools/objtool/run-command.o
> CC /usr/src/linux/tools/objtool/sigchain.o
> CC /usr/src/linux/tools/objtool/subcmd-config.o
> LD /usr/src/linux/tools/objtool/libsubcmd-in.o
> AR /usr/src/linux/tools/objtool/libsubcmd.a
> CC /usr/src/linux/tools/objtool/arch/x86/special.o
> In file included from /usr/src/linux/tools/include/linux/kernel.h:8:0,
> from /usr/src/linux/tools/include/linux/list.h:7,
> from /usr/src/linux/tools/objtool/include/objtool/arch.h:10,
> from /usr/src/linux/tools/objtool/include/objtool/check.h:11,
> from /usr/src/linux/tools/objtool/include/objtool/special.h:10,
> from arch/x86/special.c:4:
> /usr/src/linux/tools/include/asm-generic/bitops/find.h: In function 'find_next_bit':
> /usr/src/linux/tools/include/linux/bits.h:24:21: error: first argument to '__builtin_choose_expr' not a constant
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:62: note: in definition of macro 'BUILD_BUG_ON_ZERO'
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:32:17: note: in expansion of macro 'GENMASK'
> val = *addr & GENMASK(size - 1, offset);
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:51: error: bit-field '<anonymous>' width not an integer constant
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:24:3: note: in expansion of macro 'BUILD_BUG_ON_ZERO'
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:32:17: note: in expansion of macro 'GENMASK'
> val = *addr & GENMASK(size - 1, offset);
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h: In function 'find_next_and_bit':
> /usr/src/linux/tools/include/linux/bits.h:24:21: error: first argument to '__builtin_choose_expr' not a constant
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:62: note: in definition of macro 'BUILD_BUG_ON_ZERO'
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:62:27: note: in expansion of macro 'GENMASK'
> val = *addr1 & *addr2 & GENMASK(size - 1, offset);
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:51: error: bit-field '<anonymous>' width not an integer constant
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:24:3: note: in expansion of macro 'BUILD_BUG_ON_ZERO'
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:62:27: note: in expansion of macro 'GENMASK'
> val = *addr1 & *addr2 & GENMASK(size - 1, offset);
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h: In function 'find_next_zero_bit':
> /usr/src/linux/tools/include/linux/bits.h:24:21: error: first argument to '__builtin_choose_expr' not a constant
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:62: note: in definition of macro 'BUILD_BUG_ON_ZERO'
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:90:18: note: in expansion of macro 'GENMASK'
> val = *addr | ~GENMASK(size - 1, offset);
> ^
> /usr/src/linux/tools/include/linux/build_bug.h:16:51: error: bit-field '<anonymous>' width not an integer constant
> #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
> ^
> /usr/src/linux/tools/include/linux/bits.h:24:3: note: in expansion of macro 'BUILD_BUG_ON_ZERO'
> (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> ^
> /usr/src/linux/tools/include/linux/bits.h:38:3: note: in expansion of macro 'GENMASK_INPUT_CHECK'
> (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> ^
> /usr/src/linux/tools/include/asm-generic/bitops/find.h:90:18: note: in expansion of macro 'GENMASK'
> val = *addr | ~GENMASK(size - 1, offset);
> ^
> make[5]: *** [/usr/src/linux/tools/objtool/arch/x86/special.o] Error 1
> make[4]: *** [arch/x86] Error 2
> make[3]: *** [/usr/src/linux/tools/objtool/objtool-in.o] Error 2
> make[2]: *** [objtool] Error 2
> make[1]: *** [tools/objtool] Error 2
> make: *** [__sub-make] Error 2
>
>
>
> Applying below diff seems to solve the build failure.
It will desynchronize this implementation with the mother's one (i.e.
in bits.h).
> Do we need to use BUILD_BUG_ON_ZERO() here?
Rikard?
>
> diff --git a/tools/include/linux/bits.h b/tools/include/linux/bits.h
> index 7f475d59a097..0aba9294f29d 100644
> --- a/tools/include/linux/bits.h
> +++ b/tools/include/linux/bits.h
> @@ -21,8 +21,7 @@
> #if !defined(__ASSEMBLY__)
> #include <linux/build_bug.h>
> #define GENMASK_INPUT_CHECK(h, l) \
> - (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
> - __builtin_constant_p((l) > (h)), (l) > (h), 0)))
> + ({ BUILD_BUG_ON(__builtin_constant_p((l) > (h)) && ((l) > (h))); 0; })
> #else
> /*
> * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
> Also, why the fast path of find_*_bit() functions does not check
> __builtin_constant_p(offset) as well as small_const_nbits(size), for the fast
> path fails to catch BUILD_BUG_ON_ZERO() when offset argument is not a constant.
How would this help anything?
If you ask a bit from a bitmap behind the size, what do you expect to get?
And I'm a bit lost here, because I can't imagine the offset being
constant along with a size of bitmap. What do we want to achieve by
this? Any examples to better understand the case?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2021-05-10 15:45 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 0:31 [PATCH v6 00/12] lib/find_bit: fast path for small bitmaps Yury Norov
2021-04-01 0:31 ` [PATCH 01/12] tools: disable -Wno-type-limits Yury Norov
2021-04-01 0:31 ` [PATCH 02/12] tools: bitmap: sync function declarations with the kernel Yury Norov
2021-04-01 0:31 ` [PATCH 03/12] tools: sync BITMAP_LAST_WORD_MASK() macro " Yury Norov
2021-04-01 0:31 ` [PATCH 04/12] arch: rearrange headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-04-01 0:31 ` [PATCH 05/12] lib: extend the scope of small_const_nbits() macro Yury Norov
2021-04-01 8:35 ` Andy Shevchenko
2021-04-01 0:31 ` [PATCH 06/12] tools: sync small_const_nbits() macro with the kernel Yury Norov
2021-04-01 0:31 ` [PATCH 07/12] lib: inline _find_next_bit() wrappers Yury Norov
2021-04-01 8:37 ` Andy Shevchenko
2021-04-01 0:31 ` [PATCH 08/12] tools: sync find_next_bit implementation Yury Norov
2021-04-01 0:31 ` [PATCH 09/12] lib: add fast path for find_next_*_bit() Yury Norov
2021-04-01 8:48 ` Andy Shevchenko
2021-04-01 0:31 ` [PATCH 10/12] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-04-01 8:58 ` Andy Shevchenko
2021-04-01 0:31 ` [PATCH 11/12] tools: sync lib/find_bit implementation Yury Norov
2021-05-10 15:27 ` Tetsuo Handa
2021-05-10 15:44 ` Andy Shevchenko [this message]
2021-05-10 17:21 ` Yury Norov
2021-05-10 22:51 ` Rikard Falkeborn
2021-05-11 7:28 ` Andy Shevchenko
2021-05-11 10:36 ` Rikard Falkeborn
2021-05-11 11:53 ` Tetsuo Handa
2021-05-11 20:37 ` Rikard Falkeborn
2021-05-12 7:48 ` Arnd Bergmann
2021-05-12 8:15 ` Rasmus Villemoes
2021-05-12 8:33 ` Arnd Bergmann
2021-05-11 12:17 ` Andy Shevchenko
2021-04-01 0:31 ` [PATCH 12/12] MAINTAINERS: Add entry for the bitmap API Yury Norov
2021-04-01 9:14 ` [PATCH v6 00/12] lib/find_bit: fast path for small bitmaps Andy Shevchenko
2021-04-01 9:28 ` Arnd Bergmann
2021-04-01 9:50 ` Andy Shevchenko
2021-04-02 0:32 ` Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2021-03-21 21:54 [PATCH v5 " Yury Norov
2021-03-21 21:54 ` [PATCH 11/12] tools: sync lib/find_bit implementation Yury Norov
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