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| author |   Masahiro Yamada <masahiroy@kernel.org> | 2021-04-24 20:55:53 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-05-02 00:43:34 +0900 |
| commit | 3787b7da5d3e2c849fe8ffed987922a4e6dd6cfd (patch) | |
| tree | 27650170b113b1d8716174614d39b9bd254049d5 /scripts/Makefile.lib | |
| parent | sparc: syscalls: switch to generic syscallshdr.sh (diff) | |
| download | linux-dev-3787b7da5d3e2c849fe8ffed987922a4e6dd6cfd.tar.xz linux-dev-3787b7da5d3e2c849fe8ffed987922a4e6dd6cfd.zip | |
kbuild: add comment about why cmd_shipped uses 'cat'
cmd_shipped uses 'cat' instead of 'cp' for copying a file. The reason
is explained in the commit [1], but it was in the pre-git era.
$ touch a
$ chmod -w a
$ cp a b
$ cp a b
cp: cannot create regular file 'b': Permission denied
Add comments so that you can see the reason without looking into
the history.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=a70dba8086160449cc94c5bdaff78419b6b8e3c8
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'scripts/Makefile.lib')
| -rw-r--r-- | scripts/Makefile.lib | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 64daf37e874b..c0982b8b2b6d 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -252,6 +252,9 @@ quiet_cmd_copy = COPY $@ # Shipped files # =========================================================================== +# 'cp' preserves permissions. If you use it to copy a file in read-only srctree, +# the copy would be read-only as well, leading to an error when executing the +# rule next time. Use 'cat' instead in order to generate a writable file. quiet_cmd_shipped = SHIPPED $@ cmd_shipped = cat $< > $@ |