Compiling 32bit executables on 64bit system with MUSL

Compiling 32bit executables on 64bit system with MUSL

[John Found]

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I was able to do it before, although with some hassle and questions in the mailing list.
But today I tried again and it seems the old tricks does not work now.

What I am doing:

1. Compile and install MUSL for i386:

$ sudo ln -s /usr/bin/ar /usr/bin/i386-ar
$ sudo ln -s /usr/bin/ranlib /usr/bin/i386-ranlib
$ ./configure --host=i386 CC="gcc -m32"
$ make
$ sudo make install

2. edit the file /usr/local/musl/bin/musl-gcc (removing double quotes):

exec ${REALGCC:-gcc -m32} "$@" -specs "/usr/local/musl/lib/musl-gcc.specs"

3. Change the file /usr/local/musl/lib/musl-gcc.specs to the attached in this message.

As I said, this procedure happened to work before. 
But now, when trying to compile some file, the compilation failed with linker error message.

Here is some simple test:

$cat ./hello.c 
#include <stdio.h>
int main()
{
   printf("Hello, World!");
   return 0;
}

$musl-gcc -o hello ./hello.c
/usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/32/crtbegin.o: direct GOT relocation R_386_GOT32X against `_ITM_deregisterTMCloneTable' without base register can not be used when making a shared object
/usr/bin/ld: final link failed: nonrepresentable section on output
collect2: error: ld returned 1 exit status

Actually my C programming skills are very low, so I can't even understand what the linker is talking about.

The version of GCC is 8.2.0; 

Any help will be appreciated!
-- 
John Found
https://board.asm32.info

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*asm:
--32

%rename cpp_options old_cpp_options

*cpp_options:
-nostdinc -isystem /usr/local/musl/include -isystem include%s %(old_cpp_options)

*cc1:
%(cc1_cpu) -m32 -nostdinc -isystem /usr/local/musl/include -isystem include%s

*link_libgcc:
-L/usr/local/musl/lib -L .%s

*libgcc:
32/libgcc.a%s %:if-exists(32/libgcc_eh.a%s)

*startfile:
%{!shared: /usr/local/musl/lib/%{pie:S}crt1.o} /usr/local/musl/lib/crti.o %{shared|pie:crtbeginS.o%s;:32/crtbegin.o%s}

*endfile:
%{shared|pie:crtendS.o%s;:32/crtend.o%s} /usr/local/musl/lib/crtn.o

*link:
-m elf_i386 -dynamic-linker /lib/ld-musl-i386.so.1 -nostdlib %{shared:-shared} %{static:-static} %{rdynamic:-export-dynamic}

*esp_link:


*esp_options:


*esp_cpp_options:

Re: Compiling 32bit executables on 64bit system with MUSL

[Szabolcs Nagy]

* John Found <johnfound@asm32.info> [2018-09-02 16:01:25 +0300]:
> $musl-gcc -o hello ./hello.c
> /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/32/crtbegin.o: direct GOT relocation R_386_GOT32X against `_ITM_deregisterTMCloneTable' without base register can not be used when making a shared object
> /usr/bin/ld: final link failed: nonrepresentable section on output
> collect2: error: ld returned 1 exit status
> 
> Actually my C programming skills are very low, so I can't even understand what the linker is talking about.
> 
> The version of GCC is 8.2.0; 

your toolchain is probably default-pie (gcc -v will
show --enable-default-pie)

this means linking an executable will be linked like
a shared library and all object files have to be
position independent, but your specs file uses
crtbegin.o, which is non-pie, instead of crtbeginS.o
so linking fails (try passing -no-pie at link time
to gcc).

Re: Compiling 32bit executables on 64bit system with MUSL

[John Found]

On Sun, 2 Sep 2018 17:18:01 +0200
Szabolcs Nagy <nsz@port70.net> wrote:

> * John Found <johnfound@asm32.info> [2018-09-02 16:01:25 +0300]:
> > $musl-gcc -o hello ./hello.c
> > /usr/bin/ld: /usr/lib/gcc/x86_64-pc-linux-gnu/8.2.0/32/crtbegin.o: direct GOT relocation R_386_GOT32X against `_ITM_deregisterTMCloneTable' without base register can not be used when making a shared object
> > /usr/bin/ld: final link failed: nonrepresentable section on output
> > collect2: error: ld returned 1 exit status
> > 
> > Actually my C programming skills are very low, so I can't even understand what the linker is talking about.
> > 
> > The version of GCC is 8.2.0; 
> 
> your toolchain is probably default-pie (gcc -v will
> show --enable-default-pie)
> 
> this means linking an executable will be linked like
> a shared library and all object files have to be
> position independent, but your specs file uses
> crtbegin.o, which is non-pie, instead of crtbeginS.o
> so linking fails (try passing -no-pie at link time
> to gcc).

Instead of using -no-pie, I tried to replace crtbegin.o 
with crtbeginS.o (and respective crtend.o to crtendS.o)

Is it a correct fix?

After this the simple hello world compiles and runs properly.
Now I am trying to compile bigger project (sqlite3 library)
with variable success. 

In order to make it compile I was forced to use 
"-fno-stack-protector" option. I am not sure whether or not
this is a MUSL issue. The errors was like:

sqlite3.c:(.text+0x106f): undefined reference to `__stack_chk_fail_local'

Is the used workaround correct?

Also, after compiling with -O3 the library compiles but not working then.
Which is strange, but probably an issue for the sqlite mailing list.

-- 
John Found <johnfound@asm32.info>