[Linux-kernel-mentees] [PATCH] kconfig: Prepend interpeters when calling scripts

[Ujjwal Kumar]

On 26/09/20 2:53 pm, Ujjwal Kumar wrote:
> On 26/09/20 11:24 am, Lukas Bulwahn wrote:
>>
>>
>> On Sat, 26 Sep 2020, Ujjwal Kumar wrote:
>>>
>>> To unset the executable bit I ran following command:
>>> for i in $(find -executable -type f); do chmod -x $i; done
>>>
>>> One thing that I noticed is, once we initiate a kernel build some 
>>> programs are compiled and removing their executable bit is not desirable.
>>> Even after performing "make clean" some of those programs still persist and 
>>> removing their executable bit fails any further attempt to build the kernel.
>>>
>>> For instance, tools/objtool/objtool file. In my case I had a total of 19 
>>> files remaining after performing make clean.
>>>
>>
>> Good observation.
>>
>> You can properly clean your build with make mrproper, but maybe that is 
>> not even enough... all generated files might not mean _all generated 
>> tools_, such as objtool, etc.
>>
>> $ make help
>>
>> Cleaning targets:
>>   clean		  - Remove most generated files but keep the config and
>>                     enough build support to build external modules
>>   mrproper	  - Remove all generated files + config + various backup files
>>   distclean	  - mrproper + remove editor backup and patch files
>>
>> [...]
>>
>> After for i in $(find -executable -type f); do chmod -x $i; done:
>> I saw those failures (probably as you did as well):
> 
> Yes these are the same errors that I received.
> 
>>
>> *** Default configuration is based on 'x86_64_defconfig'
>> sh: 1: ./scripts/gcc-version.sh: Permission denied
>> init/Kconfig:34: syntax error
>> init/Kconfig:33: invalid statement
>> init/Kconfig:34: invalid statement
>> sh: 1: ./scripts/ld-version.sh: Permission denied
>> init/Kconfig:39: syntax error
>> init/Kconfig:38: invalid statement
>> sh: 1: ./scripts/clang-version.sh: Permission denied
>> init/Kconfig:49: syntax error
>> init/Kconfig:48: invalid statement
>> scripts/kconfig/Makefile:80: recipe for target 'defconfig' failed
>> make[1]: *** [defconfig] Error 1
>> Makefile:606: recipe for target 'defconfig' failed
>> make: *** [defconfig] Error 2
>>
>>
>> After your patch was applied, they disappear. So, it does the job.
>> More comments on the patch itself later.
>>
>> make defconfig works.
>>
> 
> Yes, these errors appeared when we unset executable bits on files after 
> performing 'make clean' and then perform a kernel build.
> 
>> make then fails:
>>
>> HOSTCC   /home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool/fixdep.o
>> /bin/sh: 1: /home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool//fixdep: Permission denied
>> /home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/build/Makefile.build:96: recipe for target 
>> '/home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool/fixdep.o' failed
>> make[4]: *** [/home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool/fixdep.o] Error 126
>> Makefile:43: recipe for target '/home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool/fixdep-in.o' failed
>> make[3]: *** [/home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/objtool/fixdep-in.o] Error 2
>> /home/lukas/repositories/kernel.org/pub/scm/linux/kernel/git/torvalds/linux/tools/build/Makefile.include:5: recipe for target 'fixdep' failed
>> make[2]: *** [fixdep] Error 2
>> Makefile:68: recipe for target 'objtool' failed
>> make[1]: *** [objtool] Error 2
>> Makefile:1885: recipe for target 'tools/objtool' failed
>> make: *** [tools/objtool] Error 2
>> make: *** Waiting for unfinished jobs....
>>
>> The make target also goes into tools/build/ and requires some targets 
>> there and then uses those tools during the further build.
>>
>> So, we need some more patches here as well.
>>
>> Can you share the list of 19 files that remained even with make clean?
>>
> 
> After performing a make clean, the files that persist are:
> ./tools/objtool/objtool
> ./tools/objtool/fixdep
> ./scripts/sorttable
> ./scripts/mod/mk_elfconfig
> ./scripts/mod/modpost
> ./scripts/unifdef
> ./scripts/basic/fixdep
> ./scripts/bin2c
> ./scripts/extract-cert
> ./scripts/kconfig/conf
> ./scripts/selinux/mdp/mdp
> ./scripts/selinux/genheaders/genheaders
> ./scripts/asn1_compiler
> ./scripts/kallsyms
> ./scripts/sign-file
> ./scripts/genksyms/genksyms
> ./scripts/recordmcount
> ./scripts/insert-sys-cert
> ./scripts/dtc/dtc
> 
> After performing 'make mrproper'/'make distclean' the files that persist 
> are:
> ./tools/objtool/objtool
> ./tools/objtool/fixdep

These files can be removed using following command from srctree:
make tools/objtool_clean

So after performing 'make mrproper' and 'make tools/objtool_clean', we get 
rid of all the compiled programs.

Instead of 'make tools/objtool_clean' we can perform following commands:
>From the srctree directory, make tools/clean
>From the tools directory, make clean
>From the tools directory, make objtool_clean
to remove the 2 files.

> 
>> Then, we go through them and check if they disappear with make mrproper or 
>> with a different make target to clean them. Potentially, we also hook 
>> those identified targets up into make mrproper then.

I tried hooking the clean task with 'make mrproper' in top-level Makefile 
as follows:

$ git diff Makefile
diff --git a/Makefile b/Makefile
index 5f1399a576d4..43ab6ce98c64 100644
--- a/Makefile
+++ b/Makefile
@@ -1498,6 +1498,7 @@ $(mrproper-dirs):
        $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
 
 mrproper: clean $(mrproper-dirs)
+       $(Q)$(MAKE) tools/objtool_clean
        $(call cmd,rmfiles)
 
 # distclean
---

Instead of '$(Q)$(MAKE) tools/objtool_clean' we can perform following 
command:
'$(Q)$(MAKE) tools/clean' to clean the entire tools/ directory.

> 
> Is it appropriate to include the files here: 
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Makefile?h=next-20200925#n1466
> ?
> Or should it be included inside tools/objtool/Makefile here:
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/tools/objtool/Makefile?h=next-20200925#n78
> ?
> In the second link, it appears to me that the files are already included for 
> clean task but still they are not cleaned.
> 
>>> Lukas
>>
> 
> Thanks
> Ujjwal Kumar
> 

Ujjwal Kumar