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Groups > linux.kernel > #1464856
| From | zijun_hu <zijun_hu@zoho.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope |
| Date | 2016-08-18 02:20 +0200 |
| Message-ID | <s7jdT-ht-3@gated-at.bofh.it> (permalink) |
| References | <s6G2R-7Xd-3@gated-at.bofh.it> <s6Hii-c3-29@gated-at.bofh.it> <s7cP8-469-35@gated-at.bofh.it> <s7iUx-8lb-3@gated-at.bofh.it> <s7jdT-ht-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 2016/8/18 7:59, Al Viro wrote: > On Thu, Aug 18, 2016 at 07:51:19AM +0800, zijun_hu wrote: >>> What the hell is anything without __KERNEL__ doing with linux/bitops.h in >>> the first place? IOW, why do we have those ifdefs at all? >>> >> >> __KERNEL__ is used to indicate the relevant sections within kernel >> headers can't be exported to or used by user space > > ITYM "used to be used". These days it's "everything outside of */uapi/*.h > can't be exported"... > i conclude one purpose of __KERNEL__ from the following kernel files scripts/headers_install.sh: echo "Usage: headers_install.sh OUTDIR SRCDIR [FILES...]" echo echo "Prepares kernel header files for use by user space, by removing" echo "all compiler.h definitions and #includes, removing any" echo "#ifdef __KERNEL__ sections, and putting __underscores__ around" echo "asm/inline/volatile keywords." echo ...... scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ "$OUTDIR/$FILE.sed" Documentation/kbuild/makefiles.txt： The kernel includes a set of headers that is exported to userspace. Many headers can be exported as-is but other headers require a minimal pre-processing before they are ready for user-space. The pre-processing does: - drop kernel-specific annotations - drop include of compiler.h - drop all sections that are kernel internal (guarded by ifdef __KERNEL__) scripts/Makefile.headersinst: # ========================================================================== # Installing headers # # header-y - list files to be installed. They are preprocessed # to remove __KERNEL__ section of the file # genhdr-y - Same as header-y but in a generated/ directory # # ==========================================================================
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[PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-16 08:30 +0200
Re: [PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope Stephen Rothwell <sfr@canb.auug.org.au> - 2016-08-16 09:00 +0200
Re: [PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-16 09:30 +0200
[RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-16 09:50 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope Al Viro <viro@ZenIV.linux.org.uk> - 2016-08-17 19:30 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-18 02:00 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-18 02:20 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope Al Viro <viro@ZenIV.linux.org.uk> - 2016-08-18 02:30 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope zijun_hu <zijun_hu@zoho.com> - 2016-08-18 03:00 +0200
Re: [RESEND PATCH 1/1] bitops.h: move out get_count_order[_long]() from __KERNEL__ scope Al Viro <viro@ZenIV.linux.org.uk> - 2016-08-18 03:10 +0200
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