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a934a57a42
The problem was described in commit 5b20755b77 ("init: move THIS_MODULE
from <linux/export.h> to <linux/init.h>").
To summarize it again here: <linux/export.h> is included by most C files,
even though only some of them actually export symbols. This is because
some headers, such as include/linux/{module.h,linkage}, needlessly
include <linux/export.h>.
I have added a more detailed explanation in the comments of
scripts/misc-check.
This problem will be fixed in two steps:
1. Add #include <linux/export.h> directly to C files that use
EXPORT_SYMBOL()
2. Remove #include <linux/export.h> from header files that do not use
EXPORT_SYMBOL()
This commit addresses step 1; scripts/misc-check will warn about *.[ch]
files that use EXPORT_SYMBOL() but do not include <linux/export.h>.
This check is only triggered when the kernel is built with W=1.
We need to fix 4000+ files. I hope others will help with this effort.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
55 lines
2.5 KiB
Bash
Executable file
55 lines
2.5 KiB
Bash
Executable file
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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set -e
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# Detect files that are tracked but ignored by git.
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check_tracked_ignored_files () {
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git -C "${srctree:-.}" ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null |
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sed 's/$/: warning: ignored by one of the .gitignore files/' >&2
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}
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# Check for missing #include <linux/export.h>
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#
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# The rule for including <linux/export.h> is very simple:
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# Include <linux/export.h> only when you use EXPORT_SYMBOL(). That's it.
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#
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# However, some headers include <linux/export.h> even though they are completely
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# unrelated to EXPORT_SYMBOL().
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#
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# One example is include/linux/module.h. Please note <linux/module.h> and
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# <linux/export.h> are orthogonal. <linux/module.h> should be included by files
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# that can be compiled as modules. In other words, <linux/module.h> should be
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# included by EXPORT_SYMBOL consumers. In contrast, <linux/export.h> should be
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# included from EXPORT_SYMBOL providers, which may or may not be modular.
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# Hence, include/linux/module.h should *not* include <linux/export.h>.
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#
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# Another example is include/linux/linkage.h, which is completely unrelated to
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# EXPORT_SYMBOL(). Worse, it is included by most C files, which means, most C
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# files end up including <linux/export.h>, even though only some of them
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# actually export symbols. Hence, include/linux/linkage.h should *not* include
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# <linux/export.h>.
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#
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# Before fixing such headers, we must ensure that C files using EXPORT_SYMBOL()
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# include <linux/export.h> directly, since many C files currently rely on
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# <linux/export.h> being included indirectly (likely, via <linux/linkage> etc.).
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#
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# Therefore, this check.
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#
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# The problem is simple - the warned files use EXPORT_SYMBOL(), but do not
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# include <linux/export.h>. Please add #include <linux/export.h> to them.
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#
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# If the included headers are sorted alphabetically, please insert
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# <linux/export.h> in the appropriate position to maintain the sort order.
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# For this reason, this script only checks missing <linux/export.h>, but
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# does not automatically fix it.
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check_missing_include_linux_export_h () {
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git -C "${srctree:-.}" grep --files-with-matches -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_GPL_FOR_MODULES)\(.*\)' \
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-- '*.[ch]' :^tools/ :^include/linux/export.h |
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xargs -r git -C "${srctree:-.}" grep --files-without-match '#include[[:space:]]*<linux/export\.h>' |
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xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing\n" >&2
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}
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check_tracked_ignored_files
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check_missing_include_linux_export_h
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