Re: [PATCH v6 00/13] GLIBC LoongArch PATCHES

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 14/07/22 08:33, Xi Ruoyao wrote:
> On Wed, 2022-07-13 at 16:55 -0300, Adhemerval Zanella Netto wrote:
> 
>> I finished my review for the port and it looks ok in general, however there
>> some pieces that would require a v7:
>>
>>   1. Add R_LARCH_NONE handling on bootstrap, binutils 2.38 does generated it 
>>      and from previous discussion it should be considered a missed 
>>      optimizations instead of a linker error.
>>
>>   2. Remove the __loongarch_soft_float parts, since there is no support for
>>      soft floating-point.
>>
>>   3. Remove sysdeps/unix/sysv/linux/loongarch/ldconfig.h, this file is not
>>      required.
>>
>>   4. Some minor style issues.
>>
>>   5. Either remove HAVE_GETTIMEOFDAY_VSYSCALL or add a gettimeofday ifunc
>>      optimization.
>>
>> The only part really prevent port inclusion is 1.  I am also assuming ifunc 
>> is support (at least you have added support on the Linux ABI part) with
>> binutils 2.38.  If not, you will need to remove support until you fix it on
>> binutils.
>>
>> And also, you need to check and report the test results using the expected
>> defined release branches, using out-of-tree branches are not acceptable for
>> inclusion.
> 
> The series tested with Linux-5.19-rc4, Binutils-2.38, and GCC-12.1. 
> Some kernel patches used but they are only boot protocols and hardware
> drivers, not related to userspace ABI so Glibc should be unaffected. 
> Some Binutils and GCC patches used but they are all already committed to
> upstream.

Thanks.

> 
> To work around binutils issues, I added R_LARCH_NONE back to
> RTLD_BOOTSTRAP, and disabled IFUNC (by adding
> libc_cv_ld_gnu_indirect_function=no into preconfigure).

I do not think this is blocker, but if you need to explicit add 
libc_cv_ld_gnu_indirect_function=no it means your toolchain can potentially
generate invalid binaries:

$ cat test.c
#include <stdio.h>

static int impl (void) { return 42; }
static void * resolver (void) { return impl; }
int ifunc (void) __attribute__((ifunc ("resolver")));

int main (int argc, char *argv[])
{
  printf ("%d\n", (int) ifunc ());
  return 0;
}
$ loongarch64-linux-gnu-hard/bin/loongarch64-glibc-linux-gnu-gcc test.c -o test
$ qemu-loongarch64 elf/ld.so --library-path . ./test
./test: error while loading shared libraries: unexpected PLT reloc type 0x0c

It would be better if you just disable ifunc support on static linker for now.

> 
> Result:
> 
> XPASS: conform/UNIX98/ndbm.h/linknamespace
> XPASS: conform/XOPEN2K/ndbm.h/linknamespace
> XPASS: conform/XOPEN2K8/ndbm.h/linknamespace
> XPASS: conform/XPG42/ndbm.h/linknamespace
> UNSUPPORTED: crypt/cert
> UNSUPPORTED: elf/tst-env-setuid
> UNSUPPORTED: elf/tst-env-setuid-tunables
> XPASS: elf/tst-protected1a
> XPASS: elf/tst-protected1b
> UNSUPPORTED: elf/tst-valgrind-smoke
> UNSUPPORTED: misc/tst-adjtimex
> UNSUPPORTED: misc/tst-clock_adjtime
> UNSUPPORTED: misc/tst-ntp_adjtime
> UNSUPPORTED: misc/tst-pkey
> UNSUPPORTED: misc/tst-rseq
> UNSUPPORTED: misc/tst-rseq-disable
> UNSUPPORTED: nptl/test-cond-printers
> UNSUPPORTED: nptl/test-condattr-printers
> UNSUPPORTED: nptl/test-mutex-printers
> UNSUPPORTED: nptl/test-mutexattr-printers
> UNSUPPORTED: nptl/test-rwlock-printers
> UNSUPPORTED: nptl/test-rwlockattr-printers
> UNSUPPORTED: nptl/tst-pthread-gdb-attach
> UNSUPPORTED: nptl/tst-pthread-gdb-attach-static
> UNSUPPORTED: nptl/tst-rseq-nptl
> UNSUPPORTED: stdlib/tst-secure-getenv
> UNSUPPORTED: time/tst-clock_settime
> UNSUPPORTED: time/tst-settimeofday
> Summary of test results:
>    4536 PASS
>      22 UNSUPPORTED
>      12 XFAIL
>       6 XPASS