[PATCH 4/5] s390: Move files out of s390-64 folders

[Stefan Liebler]

On 4/15/26 21:39, Adhemerval Zanella Netto wrote:
> 
> 
> On 09/04/26 05:47, Stefan Liebler wrote:
>> All the files in subfolders s390/s390-64 in sysdeps directory are moved
>> up to the s390/ ones.  If necessary the files were merged with the existing
>> ones.
>>
>> sysdeps/s390/preconfigure.ac was updated to reflect the removal of s390-64
>> subdirectory.
> 
> Patch looks good, just some question below if we still need some configure
> and build directives.
> 
SNIP...
>> diff --git a/sysdeps/s390/Makefile b/sysdeps/s390/Makefile
>> index 985b4f25ee..29d11dfdab 100644
>> --- a/sysdeps/s390/Makefile
>> +++ b/sysdeps/s390/Makefile
>> @@ -1,3 +1,7 @@
>> +ifeq ($(subdir),gmon)
>> +sysdep_routines += s390x-mcount
>> +endif
>> +
>>  ifeq ($(subdir),iconvdata)
>>  ISO-8859-1_CP037_Z900-routines := iso-8859-1_cp037_z900
>>  ISO-8859-1_CP037_Z900-map := gconv.map
>> @@ -43,6 +47,91 @@ $(modpfx)gconv-modules-s390.conf: ../sysdeps/s390/gconv-modules-s390.conf \
>>  endif
>>  
>>  ifeq ($(subdir),elf)
>> +CFLAGS-rtld.c += -Wno-uninitialized -Wno-unused
>> +CFLAGS-dl-load.c += -Wno-unused
>> +CFLAGS-dl-reloc.c += -Wno-unused
> 
> Do we still need these?
Good question. It seems it originally comes from sysdeps/i386/Makefile
where it is still available.I've also found:
sysdeps/m68k/Makefile:44:CFLAGS-rtld.c += -Wno-uninitialized -Wno-unused

At least with a single build of gcc 15, I don't need it (also not on
31bit). I have to dig deeper in the history why it was added in the past
and do some more tests.

As this is a change to s390-64, I would prefer to investigate first and
create a patch independent of the s390-32 removal.

SNIP...
>> diff --git a/sysdeps/s390/configure.ac b/sysdeps/s390/configure.ac
>> index 82e1a4445f..3c384f9670 100644
>> --- a/sysdeps/s390/configure.ac
>> +++ b/sysdeps/s390/configure.ac
>> @@ -133,5 +133,57 @@ then
>>    AC_DEFINE(HAVE_S390_MIN_ARCH13_ZARCH_ASM_SUPPORT)
>>  fi
>>  
>> -test -n "$critic_missing" && AC_MSG_ERROR([
>> -*** $critic_missing])
>> +# Minimal checking for static PIE support in ld.
>> +# Compare to ld testcase/bugzilla:
>> +# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd
>> +AC_CACHE_CHECK([for s390-specific static PIE requirements], \
>> +[libc_cv_s390x_staticpie_req_runtime], [dnl
>> +  cat > conftest1.c <<EOF
>> +__thread int * foo;
>> +
>> +void
>> +bar (void)
>> +{
>> +  *foo = 1;
>> +}
>> +
>> +void bar2 (void);
>> +void* bar2_ifunc (void) __asm__ ("bar2");
>> +__asm__ (".type bar2, %gnu_indirect_function");
>> +void* bar2_ifunc (void) { return 0; }
>> +EOF
>> +  cat > conftest2.c <<EOF
>> +extern __thread int *foo;
>> +extern void bar (void);
>> +extern void bar2 (void);
>> +static int x;
>> +
>> +int
>> +main ()
>> +{
>> +  foo = &x;
>> +  bar2 ();
>> +  return 0;
>> +}
>> +EOF
>> +  libc_cv_s390x_staticpie_req_runtime=no
>> +  # Check if the static linker does not generate dynamic TLS relocs in PIE
>> +  # (binutils PR ld/22263), if it accepts --no-dynamic-linker
>> +  # (by using -static-pie), and if it adds a DT_JMPREL pointing to .rela.iplt
>> +  # with static pie.
>> +  if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o]) \
>> +     && AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest2.c -o conftest2.o]) \
>> +     && AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -static-pie -nostartfiles -nostdlib -fPIE -o conftest conftest1.o conftest2.o]) \
>> +     && AC_TRY_COMMAND([! LC_ALL=C $READELF -Wr conftest | grep R_390_TLS_TPOFF] >&AS_MESSAGE_LOG_FD) \
>> +     && AC_TRY_COMMAND([LC_ALL=C $READELF -Wd conftest | grep JMPREL >&AS_MESSAGE_LOG_FD])
>> +  then
>> +    libc_cv_s390x_staticpie_req_runtime=yes
>> +  fi
>> +  rm -rf conftest.*])
>> +
>> +if test $libc_cv_s390x_staticpie_req_runtime = yes; then
>> +   # Some kernels might fail with /proc/sys/kernel/randomize_va_space set to 0
>> +   # due not enough space for a brk call.  However, there is no reliable way to
>> +   # test it.
>> +   AC_DEFINE(SUPPORT_STATIC_PIE)
>> +fi
> 
> Now that we require binutils 2.39, do we still need these check for
> static PIE?
> 
For binutils-bfd all required patches are included in binutils 2.39.

>From my tests in the past:
lld had also generated TPOFF relocations, which was fixed with llvm 19
and I think it was backported to llvm 18 release branch:
"[lld/ELF] Avoid unnecessary TPOFF relocations in GOT for -pie (#81739)"
https://github.com/llvm/llvm-project/commit/6f907733e65d24edad65f763fb14402464bd578b

But I have to dig deeper in recent lld versions. It seems as static-pie
is disabled. At least when building with llvm 21, config.h claims:
/* Define if static PIE is supported.  */
/* #undef SUPPORT_STATIC_PIE */

For gold, there is the bug:
"Bug 22221 - add --no-dynamic-linker option"
https://sourceware.org/bugzilla/show_bug.cgi?id=22221

Thus I would leave the test as is for now.





Thanks for the two points. I have to check further. But as mentioned I
would prefer to leave it as is for the s390-32 removal and do some
follow-up work.
Is this okay for you?

Thanks,
Stefan