[PATCH v5 0/6] Add support for LoongArch32

[Adhemerval Zanella Netto]

On 02/03/26 06:36, mengqinggang wrote:
> 
> 在 2026/3/2 16:05, mengqinggang 写道:
>> Add support for LoongArch32(LA32) with ilp32d abi and
>> LoongArch32 Reduced(LA32R) with ilp32s abi.
>>
>> The gcc and binutils master branch have added LA32 support.
>>
>> The kernel has added basic LA32 support[6]. But build infrastructures
>> of LoongArch32 are not enabled yet, because we need to adjust
>> irqchip drivers and wait for GNU toolchain be upstream first.
>>
>> You can build toolchains by script/build-many-glibcs.py:
>> LA32 ilp32d abi:
>> build-many-glibcs.py -j128 --keep all . compilers loongarch32-linux-gnu
>> LA32R ilp32s abi:
>> build-many-glibcs.py -j128 --keep all . compilers loongarch32-linux-gnusf
>>
>> LA32 tested by qemu-user and qemu-system.
>> Most testcases passed on LA32.
>> Tested on LA64 with no regression.
>>
>> LA32 ilp32d abi:
>> FAIL: misc/tst-pidfd
> 
> 
> misc/tst-pidfd fail because pidfd_send_signal return -1 with errno E2BIG.
> It may be cause by Linux kernel post_copy_siginfo_from_user funcion.
> 
> 3508 static int post_copy_siginfo_from_user(kernel_siginfo_t *info,
> 3509                                        const siginfo_t __user *from)
> 3510 {
> 3511         if (unlikely(!known_siginfo_layout(info->si_signo, info->si_code))) {
> 3512                 char __user *expansion = si_expansion(from);
> 3513                 char buf[SI_EXPANSION_SIZE];
> 3514                 int i;
> 3515                 /*
> 3516                  * An unknown si_code might need more than
> 3517                  * sizeof(struct kernel_siginfo) bytes.  Verify all of the
> 3518                  * extra bytes are 0.  This guarantees copy_siginfo_to_user
> 3519                  * will return this data to userspace exactly.
> 3520                  */
> 3521                 if (copy_from_user(&buf, expansion, SI_EXPANSION_SIZE))
> 3522                         return -EFAULT;
> 3523                 for (i = 0; i < SI_EXPANSION_SIZE; i++) {
> 3524                         if (buf[i] != 0)
> 3525                                 return -E2BIG;
> 3526                 }
> 3527         }
> 3528         return 0;
> 3529 }
> 
> If init siginfo_t to 0, the test can pass.
> 
> --- a/sysdeps/unix/sysv/linux/tst-pidfd.c
> +++ b/sysdeps/unix/sysv/linux/tst-pidfd.c
> @@ -210,13 +210,13 @@ do_test (void)
>    /* Wait for second sigtimedwait.  */
>    support_process_state_wait (pid, support_process_state_sleeping);
>    {
> -    siginfo_t info =
> +    siginfo_t info = {0};
>        {
> -       .si_signo = SIGUSR2,
> -       .si_errno = EAGAIN,
> -       .si_code = -10,
> -       .si_pid = ppid,
> -       .si_uid = puid
> +       info.si_signo = SIGUSR2;
> +       info.si_errno = EAGAIN;
> +       info.si_code = -10;
> +       info.si_pid = ppid;
> +       info.si_uid = puid;
>        };
>      TEST_COMPARE (pidfd_send_signal (pidfd, SIGUSR2, &info, 0), 0);
>    }
> 
> Should it be modified in this way?

I have sent a similar patch during 2.43 release [1], and we did not have consensus
if this the correct approach.

[1] https://patchwork.sourceware.org/project/glibc/patch/20260120131337.2574254-1-adhemerval.zanella@linaro.org/