[PATCH v2 5/5] Linux: Consolidate auxiliary vector parsing

[Szabolcs Nagy]

this broke aarch64 static binaries:

The 02/03/2022 12:08, Florian Weimer via Libc-alpha wrote
>  void
>  _dl_aux_init (ElfW(auxv_t) *av)
>  {
> -  int seen = 0;
> -  uid_t uid = 0;
> -  gid_t gid = 0;
> -
>  #ifdef NEED_DL_SYSINFO
>    /* NB: Avoid RELATIVE relocation in static PIE.  */
>    GL(dl_sysinfo) = DL_SYSINFO_DEFAULT;
>  #endif
>  
>    _dl_auxv = av;
> -  for (; av->a_type != AT_NULL; ++av)
> -    switch (av->a_type)
> -      {
> -      case AT_PAGESZ:
> -	if (av->a_un.a_val != 0)
> -	  GLRO(dl_pagesize) = av->a_un.a_val;
> -	break;
> -      case AT_CLKTCK:
> -	GLRO(dl_clktck) = av->a_un.a_val;
> -	break;
> -      case AT_PHDR:
> -	GL(dl_phdr) = (const void *) av->a_un.a_val;
> -	break;
> -      case AT_PHNUM:
> -	GL(dl_phnum) = av->a_un.a_val;
> -	break;
> -      case AT_PLATFORM:
> -	GLRO(dl_platform) = (void *) av->a_un.a_val;
> -	break;
> -      case AT_HWCAP:
> -	GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
> -	break;
> -      case AT_HWCAP2:
> -	GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val;
> -	break;
> -      case AT_FPUCW:
> -	GLRO(dl_fpu_control) = av->a_un.a_val;
> -	break;
> -#ifdef NEED_DL_SYSINFO
> -      case AT_SYSINFO:
> -	GL(dl_sysinfo) = av->a_un.a_val;
> -	break;
> -#endif
> -#ifdef NEED_DL_SYSINFO_DSO
> -      case AT_SYSINFO_EHDR:
> -	GL(dl_sysinfo_dso) = (void *) av->a_un.a_val;
> -	break;
> -#endif
> -      case AT_UID:
> -	uid ^= av->a_un.a_val;
> -	seen |= 1;
> -	break;
> -      case AT_EUID:
> -	uid ^= av->a_un.a_val;
> -	seen |= 2;
> -	break;
> -      case AT_GID:
> -	gid ^= av->a_un.a_val;
> -	seen |= 4;
> -	break;
> -      case AT_EGID:
> -	gid ^= av->a_un.a_val;
> -	seen |= 8;
> -	break;
> -      case AT_SECURE:
> -	seen = -1;
> -	__libc_enable_secure = av->a_un.a_val;
> -	__libc_enable_secure_decided = 1;
> -	break;
> -      case AT_RANDOM:
> -	_dl_random = (void *) av->a_un.a_val;
> -	break;
> -      case AT_MINSIGSTKSZ:
> -	_dl_minsigstacksize = av->a_un.a_val;
> -	break;
> -      DL_PLATFORM_AUXV
> -      }
> -  if (seen == 0xf)
> -    {
> -      __libc_enable_secure = uid != 0 || gid != 0;
> -      __libc_enable_secure_decided = 1;
> -    }
> +  dl_parse_auxv_t auxv_values = { 0, };
> +  _dl_parse_auxv (av, auxv_values);

this seems to use memset now on aarch64 before irelative
relocs are resolved in static binaries.

which causes infinite loops in the iplt (i've also seen
segfaults in the build log).

i wonder what is a clean fix...