[PATCH] Replace use of perl with sed and tr in s390x build.

[PATCH] Replace use of perl with sed and tr in s390x build.

[Rob Landley]

From: Rob Landley <rob@landley.net>

Commit 246218962e21 in November added a perl dependency to the s390x vmlinux
build, complicating the "countering trusting trust" build approach ala
http://lists.landley.net/pipermail/toybox-landley.net/2020-July/011898.html

Signed-off-by: Rob Landley <rob@landley.net>
---

 arch/s390/boot/compressed/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile
index de18dab518bb..e941b165bd4f 100644
--- a/arch/s390/boot/compressed/Makefile
+++ b/arch/s390/boot/compressed/Makefile
@@ -33,7 +33,7 @@ $(obj)/vmlinux.syms: $(obj)/vmlinux.lds $(objtree)/arch/s390/boot/startup.a $(OB
 
 quiet_cmd_dumpsyms = DUMPSYMS $<
 define cmd_dumpsyms
-	$(NM) -n -S --format=bsd "$<" | $(PERL) -ne '/(\w+)\s+(\w+)\s+[tT]\s+(\w+)/ and printf "%x %x %s\0",hex $$1,hex $$2,$$3' > "$@"
+	$(NM) -n -S --format=bsd "$<" | sed -nE 's/^0*([0-9a-fA-F]+) 0*([0-9a-fA-F]+) [tT] ([^ ]*)$$/\1 \2 \3/p' | tr '\n' '\0' > "$@"
 endef
 
 $(obj)/syms.bin: $(obj)/vmlinux.syms FORCE

Re: [PATCH] Replace use of perl with sed and tr in s390x build.

[Vasily Gorbik]

On Mon, May 17, 2021 at 11:46:44PM -0500, Rob Landley wrote:
> From: Rob Landley <rob@landley.net>
> 
> Commit 246218962e21 in November added a perl dependency to the s390x vmlinux
> build, complicating the "countering trusting trust" build approach ala
> http://lists.landley.net/pipermail/toybox-landley.net/2020-July/011898.html
> 
> Signed-off-by: Rob Landley <rob@landley.net>
> ---
> 
>  arch/s390/boot/compressed/Makefile |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile
> index de18dab518bb..e941b165bd4f 100644
> --- a/arch/s390/boot/compressed/Makefile
> +++ b/arch/s390/boot/compressed/Makefile
> @@ -33,7 +33,7 @@ $(obj)/vmlinux.syms: $(obj)/vmlinux.lds $(objtree)/arch/s390/boot/startup.a $(OB
>  
>  quiet_cmd_dumpsyms = DUMPSYMS $<
>  define cmd_dumpsyms
> -	$(NM) -n -S --format=bsd "$<" | $(PERL) -ne '/(\w+)\s+(\w+)\s+[tT]\s+(\w+)/ and printf "%x %x %s\0",hex $$1,hex $$2,$$3' > "$@"
> +	$(NM) -n -S --format=bsd "$<" | sed -nE 's/^0*([0-9a-fA-F]+) 0*([0-9a-fA-F]+) [tT] ([^ ]*)$$/\1 \2 \3/p' | tr '\n' '\0' > "$@"
>  endef

The change itself is fine. Yields the same result as before with
binutils/llvm/elfutils versions of nm.

With s390 defconfig there is at least another perl invocation via
./lib/build_OID_registry, which is hard to get rid of. debug_defconfig calls
./scripts/headers_check.pl on top. Perl is explicitly listed in "Minimal
requirements to compile the Kernel" in Documentation/process/changes.rst and
quite frankly I'm not aware of any plans to get rid of it. It has its use.

So, would you mind if I pick your patch changing the commit message
like the following?
"""
s390/decompressor: replace use of perl with simple sed/tr

Use simple sed/tr instead of perl to generate decompressor symbols
file with the same result.

Signed-off-by: Rob Landley <rob@landley.net>
"""

Re: [PATCH] Replace use of perl with sed and tr in s390x build.

[Rob Landley]

On 5/31/21 4:55 PM, Vasily Gorbik wrote:
> On Mon, May 17, 2021 at 11:46:44PM -0500, Rob Landley wrote:
>> From: Rob Landley <rob@landley.net>
>>
>> Commit 246218962e21 in November added a perl dependency to the s390x vmlinux
>> build, complicating the "countering trusting trust" build approach ala
>> http://lists.landley.net/pipermail/toybox-landley.net/2020-July/011898.html
>>
>> Signed-off-by: Rob Landley <rob@landley.net>
>> ---
>>
>>  arch/s390/boot/compressed/Makefile |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile
>> index de18dab518bb..e941b165bd4f 100644
>> --- a/arch/s390/boot/compressed/Makefile
>> +++ b/arch/s390/boot/compressed/Makefile
>> @@ -33,7 +33,7 @@ $(obj)/vmlinux.syms: $(obj)/vmlinux.lds $(objtree)/arch/s390/boot/startup.a $(OB
>>  
>>  quiet_cmd_dumpsyms = DUMPSYMS $<
>>  define cmd_dumpsyms
>> -	$(NM) -n -S --format=bsd "$<" | $(PERL) -ne '/(\w+)\s+(\w+)\s+[tT]\s+(\w+)/ and printf "%x %x %s\0",hex $$1,hex $$2,$$3' > "$@"
>> +	$(NM) -n -S --format=bsd "$<" | sed -nE 's/^0*([0-9a-fA-F]+) 0*([0-9a-fA-F]+) [tT] ([^ ]*)$$/\1 \2 \3/p' | tr '\n' '\0' > "$@"
>>  endef
> 
> The change itself is fine. Yields the same result as before with
> binutils/llvm/elfutils versions of nm.

...

> So, would you mind if I pick your patch changing the commit message
> like the following?
> """
> s390/decompressor: replace use of perl with simple sed/tr
> 
> Use simple sed/tr instead of perl to generate decompressor symbols
> file with the same result.

Works for me.

> Signed-off-by: Rob Landley <rob@landley.net>
> """

Thanks,

Rob