Re: [PATCH 1/2] ld.so: Implement the --list-diagnostics option

[Florian Weimer <fweimer@redhat.com>]

* H. J. Lu via Libc-alpha:

>> +void
>> +_dl_diagnostics_print_labeled_value (const char *label, uint64_t value)
>> +{
>> +  if (sizeof (value) == sizeof (unsigned long int))
>> +    /* _dl_printf can print 64-bit values directly.  */
>> +    _dl_printf ("%s=0x%lx\n", label, (unsigned long int) value);
>> +  else
>> +    {
>> +      uint32_t high = value >> 32;
>> +      uint32_t low = value;
>> +      if (high == 0)
>> +        _dl_printf ("%s=0x%x\n", label, low);
>> +      else
>> +        _dl_printf ("%s=0x%x%08x\n", label, high, low);
>> +    }
>> +}
>
> You want to print out everything in strings and values.

If I don't know that the value is a valid pointer, I can't print it as a
string.

>> +  static const char unfiltered[] =
>> +    "DATEMSK\0"
>> +    "GCONV_PATH\0"
>> +    "GETCONF_DIR\0"
>> +    "GETCONF_DIR\0"
>> +    "GLIBC_TUNABLES\0"
>> +    "GMON_OUTPUT_PREFIX\0"
>> +    "HESIOD_CONFIG\0"
>> +    "HES_DOMAIN\0"
>> +    "HOSTALIASES\0"
>> +    "I18NPATH\0"
>> +    "IFS\0"
>> +    "LANG\0"
>> +    "LOCALDOMAIN\0"
>> +    "LOCPATH\0"
>> +    "MSGVERB\0"
>> +    "NIS_DEFAULTS\0"
>> +    "NIS_GROUP\0"
>> +    "NIS_PATH\0"
>> +    "NLSPATH\0"
>> +    "PATH\0"
>> +    "POSIXLY_CORRECT\0"
>> +    "RESOLV_HOST_CONF\0"
>> +    "RES_OPTIONS\0"
>> +    "SEV_LEVEL\0"
>> +    "TMPDIR\0"
>> +    "TZ\0"
>> +    "TZDIR\0"
>
> Any particular reason to have double '\0' at the end of string?
> Will a single  '\0' work?

It's necessary to recognize the end of the list.

>> +/* On Hurd, uname is not available on ld.so.  This corresponds to a
>> +   missing domainname member.  */
>> +#define PRINT_UNAME (_UTSNAME_DOMAIN_LENGTH > 0)
>> +
>> +#if PRINT_UNAME
>> +/* Print one uname entry.  */
>> +static void
>> +print_utsname_entry (const char *field, const char *value)
>> +{
>> +  _dl_printf ("uname.");
>> +  _dl_diagnostics_print_labeled_string (field, value);
>> +}
>> +
>> +/* Print information from uname, including the kernel version.  */
>> +static void
>> +print_uname (void)
>> +{
>> +  struct utsname uts;
>> +  if (__uname (&uts) == 0)
>> +    {
>> +      print_utsname_entry ("sysname", uts.sysname);
>> +      print_utsname_entry ("nodename", uts.nodename);
>> +      print_utsname_entry ("release", uts.release);
>> +      print_utsname_entry ("version", uts.version);
>> +      print_utsname_entry ("machine", uts.machine);
>> +      print_utsname_entry ("domainname", uts.domainname);
>> +    }
>> +}
>> +#endif
>
> Put it under sysdeps/generic?

Okay, will do that.

Thanks,
Florian