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Date:   Thu, 31 Oct 2019 14:41:16 +0100
From:   Jessica Yu <jeyu@kernel.org>
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Matthias Maennich <maennich@google.com>
Subject: Re: [PATCH 4/4] scripts/nsdeps: make sure to pass all module source
 files to spatch
Message-ID: <20191031134115.GE2177@linux-8ccs>
References: <20191028151427.31612-1-jeyu@kernel.org>
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 <20191030161726.GA13413@linux-8ccs>
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+++ Masahiro Yamada [31/10/19 21:27 +0900]:
>On Thu, Oct 31, 2019 at 1:17 AM Jessica Yu <jeyu@kernel.org> wrote:
>>
>> +++ Masahiro Yamada [29/10/19 21:57 +0900]:
>> >On Tue, Oct 29, 2019 at 12:14 AM Jessica Yu <jeyu@kernel.org> wrote:
>> >>
>> >> The nsdeps script passes a list of the module source files to
>> >> generate_deps_for_ns() as a space delimited string named $mod_source_files,
>> >> which then passes it to spatch. But since $mod_source_files is not encased
>> >> in quotes, each source file in that string is treated as a separate shell
>> >> function argument (as $2, $3, $4, etc.).  However, the spatch invocation
>> >> only refers to $2, so only the first file out of $mod_source_files is
>> >> processed by spatch.
>> >>
>> >> This causes problems (namely, the MODULE_IMPORT_NS() statement doesn't
>> >> get inserted) when a module is composed of many source files and the
>> >> "main" module file containing the MODULE_LICENSE() statement is not the
>> >> first file listed in $mod_source_files. Fix this by encasing
>> >> $mod_source_files in quotes so that the entirety of the string is
>> >> treated as a single argument and can be referred to as $2.
>> >>
>> >> Signed-off-by: Jessica Yu <jeyu@kernel.org>
>> >> ---
>> >>  scripts/nsdeps | 2 +-
>> >>  1 file changed, 1 insertion(+), 1 deletion(-)
>> >>
>> >> diff --git a/scripts/nsdeps b/scripts/nsdeps
>> >> index 9ddcd5cb96b1..5055b059a81b 100644
>> >> --- a/scripts/nsdeps
>> >> +++ b/scripts/nsdeps
>> >> @@ -36,7 +36,7 @@ generate_deps() {
>> >>                                               | sed -E "s%(^|\s)([^/][^ ]*)%\1$srctree/\2%g"`
>> >>         for ns in `cat $ns_deps_file`; do
>> >>                 echo "Adding namespace $ns to module $mod_name (if needed)."
>> >> -               generate_deps_for_ns $ns $mod_source_files
>> >> +               generate_deps_for_ns $ns "$mod_source_files"
>> >>                 # sort the imports
>> >>                 for source_file in $mod_source_files; do
>> >>                         sed '/MODULE_IMPORT_NS/Q' $source_file > ${source_file}.tmp
>> >
>> >I think this change is correct, but
>> >did you succeed in nsdeps for composite modules
>> >with this patch only?
>> >
>> >I think the following is needed too:
>> >
>> >
>> >diff --git a/scripts/nsdeps b/scripts/nsdeps
>> >index dda6fbac016e..5a23ea616446 100644
>> >--- a/scripts/nsdeps
>> >+++ b/scripts/nsdeps
>> >@@ -31,9 +31,9 @@ generate_deps() {
>> >        local mod_file=`echo $@ | sed -e 's/\.ko/\.mod/'`
>> >        local ns_deps_file=`echo $@ | sed -e 's/\.ko/\.ns_deps/'`
>> >        if [ ! -f "$ns_deps_file" ]; then return; fi
>> >-       local mod_source_files=`cat $mod_file | sed -n 1p                      \
>> >+       local mod_source_files="`cat $mod_file | sed -n 1p
>> >         \
>> >                                              | sed -e 's/\.o/\.c/g'           \
>> >-                                             | sed "s|[^ ]* *|${srctree}/&|g"`
>> >+                                             | sed "s|[^ ]* *|${srctree}/&|g"`"
>> >        for ns in `cat $ns_deps_file`; do
>> >                echo "Adding namespace $ns to module $mod_name (if needed)."
>> >                generate_deps_for_ns $ns $mod_source_files
>> >
>> >
>> >Without this, a module that consists of two files
>> >will be expanded to:
>> >
>> >local mod_source_files=source1.c source2.c
>>
>> Yes, I was able to have nsdeps work for composite modules with just my
>> patch. Without this patch applied, the script produces the following
>> expansion of the generate_deps_for_ns call, (I just added a test
>> namespace MODULE):
>>
>> Adding namespace MODULE to module fs/nfs/nfs.ko.
>> + generate_deps_for_ns MODULE /tmp/ppyu/linux/fs/nfs/client.c /tmp/ppyu/linux/fs/nfs/dir.c /tmp/ppyu/linux/fs/nfs/file.c /tmp/ppyu/linux/fs/nfs/getroot.c /tmp/ppyu/linux/fs/nfs/inode.c /tmp/ppyu/linux/fs/nfs/super.c /tmp/ppyu/linux/fs/nfs/io.c /tmp/ppyu/linux/fs/nfs/direct.c /tmp/ppyu/linux/fs/nfs/pagelist.c /tmp/ppyu/linux/fs/nfs/read.c /tmp/ppyu/linux/fs/nfs/symlink.c /tmp/ppyu/linux/fs/nfs/unlink.c /tmp/ppyu/linux/fs/nfs/write.c /tmp/ppyu/linux/fs/nfs/namespace.c /tmp/ppyu/linux/fs/nfs/mount_clnt.c /tmp/ppyu/linux/fs/nfs/nfstrace.c /tmp/ppyu/linux/fs/nfs/export.c /tmp/ppyu/linux/fs/nfs/sysfs.c /tmp/ppyu/linux/fs/nfs/sysctl.c /tmp/ppyu/linux/fs/nfs/fscache.c /tmp/ppyu/linux/fs/nfs/fscache-index.c
>> + /usr/bin/spatch --very-quiet --in-place --sp-file /tmp/ppyu/linux/scripts/coccinelle/misc/add_namespace.cocci -D ns=MODULE /tmp/ppyu/linux/fs/nfs/client.c
>>
>> So only the first file got included in the spatch invocation. But the
>> spatch call gets fixed with all the files when quotes are added in the
>> call to generate_deps_for_ns.
>>
>> But we need to include your change anyway, to make the script more
>> robust.
>
>Hmm.
>With this patch only, I see "bad variable name" error.
>
>
>
>masahiro@grover:~/ref/linux$ make -j8  nsdeps
>  DESCEND  objtool
>  CALL    scripts/atomic/check-atomics.sh
>  CALL    scripts/checksyscalls.sh
>  CHK     include/generated/compile.h
>  Building modules, stage 2.
>  MODPOST 20 modules
>WARNING: module nfs uses symbol foo from namespace USB_STORAGE, but
>does not import it.
>  Building modules, stage 2.
>  MODPOST 20 modules
>./scripts/nsdeps: 34: local: ./fs/nfs/dir.c: bad variable name
>make: *** [Makefile;1689: nsdeps] Error 2

Hm, I was having trouble reproducing this until I changed the shell to
dash, /bin/sh is a symlink to bash on my system, that might explain
slightly different behavior. In any case, we should add quotes in both
places.

>> It would probably prevent more shell script related bugs in
>> the future (Like [1]). I can respin this patch only while the other
>> ones are superceded by your patchset.
>>
>> [1] https://unix.stackexchange.com/a/131767
>
>Anyway.
>
>Is this patch aiming for v5.4 (i.e. fixes) or v5.5-rc1 ?

I am hoping for fixes, we should try to get all the small bugs out of
nsdeps by 5.4 if we can..

>If you touch the mod_source_files line,
>we will have a conflict because
>https://patchwork.kernel.org/patch/11217839/
>is touching the same line.
>
>How should we organize the patch order?

Would you like to fold these changes into your nsdeps improvements
patchset? Since it's a pretty trivial change.

Thanks!