[PATCH] alpha: Fix generic brk system call emulation in __brk_call (bug 29490)

[Florian Weimer]

* Florian Weimer via Libc-alpha:

> The kernel special-cases the zero argument for alpha brk, and we can
> use that to restore the generic Linux error handling behavior.
>
> This change fixes an ldconfig crash under qemu-user for me.
>
> ---
>  sysdeps/unix/sysv/linux/alpha/brk_call.h | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/alpha/brk_call.h b/sysdeps/unix/sysv/linux/alpha/brk_call.h
> index b8088cf13f..0b851b6c86 100644
> --- a/sysdeps/unix/sysv/linux/alpha/brk_call.h
> +++ b/sysdeps/unix/sysv/linux/alpha/brk_call.h
> @@ -21,8 +21,7 @@ __brk_call (void *addr)
>  {
>    unsigned long int result = INTERNAL_SYSCALL_CALL (brk, addr);
>    if (result == -ENOMEM)
> -    /* Mimic the default error reporting behavior.  */
> -    return addr;
> -  else
> -    return (void *) result;
> +    /* Mimic the generic error reporting behavior.  */
> +    result = INTERNAL_SYSCALL_CALL (brk, 0);
> +  return (void *) result;
>  }

I've pushed this because I received confirmation on the bug that this
fixes things.

Thanks,
Florian