Groups > linux.kernel > #1207264

Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu

From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [regression] x86/signal/64: Fix SS handling for signals delivered to 64-bit programs breaks dosemu
Date	2015-08-14 02:30 +0200
Message-ID	<pXb2G-2yG-9@gated-at.bofh.it> (permalink)
References	(13 earlier) <pX9kd-8uM-17@gated-at.bofh.it> <pX9DA-q0-11@gated-at.bofh.it> <pX9Nf-QH-21@gated-at.bofh.it> <pXaJj-2bP-3@gated-at.bofh.it> <pXaJk-2bP-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Thu, Aug 13, 2015 at 5:08 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Thu, Aug 13, 2015 at 5:00 PM, Stas Sergeev <stsp@list.ru> wrote:
>> 14.08.2015 02:00, Andy Lutomirski пишет:
>>>
>>> DOSEMU, when you set that flag, WRFSBASE gets enabled, and glibc's
>>> threading library starts using WRFSBASE instead of arch_prctl.
>>
>> Hmm, how about the following:
>>
>> prctl(ARCH_SET_SIGNAL_FS, my_tls)
>> If my_tls==NULL - use current fsbase (including one of WRFSBASE).
>> If my_tls==(void)-1 - don't restore.
>>
>> Can this work?
>
> I'm really inclined to wonder whether we need the change and such a flag at all.
>
> Basically, no _normal_ application will ever play with segments at all
> on x86-64. So our current behavior of not touching any segments at all
> for signal handling would seem to be the right thing to do - because
> it handles all the sane cases optimally.
>
> And applications that *do* play with segments very much know they do
> so, and we already put the onus on *them* to save/restore segments.
> That's how dosemu clearly works today.

I agree for all but CS and SS, which are special.  CS is fine already.
The way that DOSEMU works around SS it is hideous: it just gives up on
sigreturn working and fixes the segments with IRET.  (Also, if DOSEMU
ever wants to get ESP[31:16] right, it *can't*: only the kernel can
usefully do espfix64, and DOSEMU can't get the kernel to return from
64-bit code to 16-bit code, because we zap SS.  DOSEMU fudges it by
forcibly zeroing ESP[31:16]), but that's not a full solution and I
wouldn't be surprised if something breaks as a result.

So yes, it mostly works.  It also sucks, and it makes it extremely
unpleasant for any other program to do this.  I'd argue that keeping
things like the sigreturn_64 test working is quite valuable, because
it's a royal PITA to exercise this code cleanly without proper control
of SS.  Unfortunately, making it hard for sigreturn_64 to exercise
this stuff doesn't mean that the bad guys can't do it, because they'll
use malformed ELF files, or ptrace, or stupid modify_ldt races (except
I hopefully fixed those), or x32, or compat, or some other hack I
haven't thought of yet, and they'll hit the same bugs.  I've lost
count of the number of bugs of various severities that the sigreturn
tests have shaken out *and* caught in patches that were emailed in.

We could say "forget sigreturn_64, use sigreturn_32 instead", but that
can't exercise !IA32_EMULATION kernels, and that code is a bit
different.

(BadIRET, for example, is nominally unreachable from 64-bit code
without modify_ldt and the sigreturn fix, except that I think know of
one really nasty way to do it.  I have no intention of implementing
that, so keeping selftests working nicely makes me *much* more
confident.)

Obviously, if we reintroduce SS restoration, we need to do it much
more carefully.  My RFC patches are an attempt to do that, but it
needs a lot of care to make sure all the bases are covered.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

[regression] x86/signal/64: Fix SS handling for signals delivered to  64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 02:20 +0200
  Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 02:40 +0200
    Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 10:30 +0200
      Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 18:20 +0200
        Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 19:10 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 20:30 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 21:00 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 21:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 22:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 23:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-12 23:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 00:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 00:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals  delivered to 64-bit programs breaks dosemu Ingo Molnar <mingo@kernel.org> - 2015-08-13 10:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 12:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 14:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 17:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 19:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 19:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 19:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 18:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 13:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-12 22:50 +0200
  Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 17:40 +0200
    Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 17:50 +0200
      Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:20 +0200
        Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:30 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:40 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 18:50 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 18:50 +0200
      Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Brian Gerst <brgerst@gmail.com> - 2015-08-13 19:10 +0200
        Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:40 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 00:50 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 11:40 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 17:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 18:40 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 00:50 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-19 12:20 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-19 17:40 +0200
      Re: [regression] x86/signal/64: Fix SS handling for signals  delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 10:20 +0200
    Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 20:00 +0200
      Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 20:40 +0200
        Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 20:50 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:10 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 21:50 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 22:20 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:00 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals  delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-13 22:10 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-13 23:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 23:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-14 00:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 01:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 01:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Raymond Jennings <shentino@gmail.com> - 2015-08-14 01:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 00:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 00:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 00:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 01:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 01:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 02:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 02:20 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 03:00 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 03:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 03:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 04:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 03:40 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-14 02:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-14 02:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-14 02:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals  delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 09:30 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Pavel Emelyanov <xemul@parallels.com> - 2015-08-14 12:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals  delivered to 64-bit programs breaks dosemu Cyrill Gorcunov <gorcunov@gmail.com> - 2015-08-14 13:00 +0200
        Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:00 +0200
          Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Andy Lutomirski <luto@amacapital.net> - 2015-08-13 21:10 +0200
            Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 21:20 +0200
              Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 21:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Linus Torvalds <torvalds@linux-foundation.org> - 2015-08-13 22:10 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-18 08:50 +0200
                Re: [regression] x86/signal/64: Fix SS handling for signals delivered  to 64-bit programs breaks dosemu Stas Sergeev <stsp@list.ru> - 2015-08-13 22:10 +0200

csiph-web