Re: [PATCH] Remove #ifdef CONFIG_64BIT from all asm-generic/fcntl.h

From: Palmer Dabbelt
Date: Mon Sep 07 2015 - 09:35:46 EST

On Mon, 07 Sep 2015 06:16:37 PDT (-0700), arnd@xxxxxxxx wrote:
> On Tuesday 01 September 2015 17:10:10 Palmer Dabbelt wrote:
>> From: Palmer Dabbelt <palmer.dabbelt@xxxxxxxxxxxxxxxxx>
>> When working on the RISC-V port I noticed that F_SETLK64 was being
>> defined on our 64-bit platform, despite our port being so new that
>> we've only ever had the 64-bit file ops. Since there's not compat
>> layer for these, this causes fcntl to bail out.
>> It turns out that one of the ways in with F_SETLK64 was being defined
>> (there's some more in glibc, but that's a whole different story... :))
>> is the result of CONFIG_64BIT showing up in this user-visible header.
>> <asm-generic/bitsperlong.h> confirms this isn't sane, so I replaced it
>> with a __BITS_PER_LONG check.
>> I went ahead and grep'd for any more of these (with
>> headers_install_all), and this was the only one I found.
>> Signed-off-by: Palmer Dabbelt <palmer.dabbelt@xxxxxxxxxxxxxxxxx>
>> Reviewed-by: Andrew Waterman <waterman@xxxxxxxxxxxxxxxxx>
>> Reviewed-by: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
> Looks good to me. Are you planning to submit the RISC-V port upstream
> any time soon? If so, just keep the patch in your tree and add my
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>

The RISC-V stuff is still a few months off, that's why I submitted this
upstream stand-alone. The supervisor specification isn't 100% set in
stone yet, and we're waiting on that before upstreaming anything

> However, I did see a lot of similar bugs now that you point me to it:
> $ grep -r \\\<CONFIG obj-tmp/usr/include/
> obj-tmp/usr/include/asm-generic/fcntl.h:#ifndef CONFIG_64BIT
> obj-tmp/usr/include/asm-generic/mman-common.h:#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED
> obj-tmp/usr/include/asm-generic/unistd.h:#ifdef CONFIG_MMU
> obj-tmp/usr/include/asm-generic/unistd.h:#endif /* CONFIG_MMU */
> obj-tmp/usr/include/linux/atmdev.h:#ifdef CONFIG_COMPAT
> obj-tmp/usr/include/linux/elfcore.h:#ifdef CONFIG_BINFMT_ELF_FDPIC
> obj-tmp/usr/include/linux/eventpoll.h:#ifdef CONFIG_PM_SLEEP
> obj-tmp/usr/include/linux/fb.h:#ifdef CONFIG_FB_BACKLIGHT
> obj-tmp/usr/include/linux/flat.h:#ifdef CONFIG_BINFMT_SHARED_FLAT
> obj-tmp/usr/include/linux/hw_breakpoint.h:#ifdef CONFIG_HAVE_MIXED_BREAKPOINTS_REGS
> obj-tmp/usr/include/linux/pktcdvd.h:#if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
> obj-tmp/usr/include/linux/raw.h:#define MAX_RAW_MINORS CONFIG_MAX_RAW_DEVS
> obj-tmp/usr/include/asm/ptrace.h:#ifdef CONFIG_CPU_ENDIAN_BE8
> These all have the same problem, and we should fix them, as well as
> (probably) adding an automated check to scripts/

Well, I was going to go fix them all and ran a very similar grep, but
I think I got a lot of false-positives. If I understand correctly,
it's allowed to have CONFIG_* when guarded by __KERNEL__ in
user-visible headers?

Now that I've written that, I realize it'd be pretty easy to just use
cpp to drop everything inside __KERNEL__ and then look for CONFIG_*.
If you want, I can try to do that, fix what triggers the check, and
re-submit everything together?
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