On Tue, Sep 24, 2013 at 9:47 PM, Tsutomu Oyamada <[email protected]>wrote:

> Hi, Dave.
>
> Thanks for your advice and quick respons.
> I tried it.
>
> ----
> fp_digit: 8
> unsigned long: 8
> FP_64BIT not defined
> DIGIT_BIT: 64
> CHAR_BIT: 8
> FP_MAX_SIZE: 8704
> FP_SIZE: 136
> TFM_ASM not defined
> fp_word: 8
> ulong64: 8
> unsigned long long: 8
> CRYPT not defined
> ----
>
> What should I just do in order to fix this problem?
> Please teach me how to set size of fp_word to 16.
>
> T.Oyamada
>
> On Tue, 24 Sep 2013 18:16:26 -0400
> David Raynor <[email protected]> wrote:
>
> > On Tue, Sep 24, 2013 at 4:37 PM, David Raynor <[email protected]
> >wrote:
> >
> > > On Tue, Sep 24, 2013 at 2:05 AM, Tsutomu Oyamada <
> [email protected]>wrote:
> > >
> > >> Hi,
> > >>
> > >> I investigated the value using the following programs.
> > >>
> > >> ----
> > >> #include "stdlib.h"
> > >> #include "bignum_fast.h"
> > >>
> > >> int main(int argc, char **argv) {
> > >>
> > >>         printf("fp_digit: %d\n",sizeof(fp_digit));
> > >>         printf("unsigned long: %d\n",sizeof(unsigned long));
> > >>
> > >> #ifdef FP_64BIT
> > >>         printf("FP_64BIT: %d\n",FP_64BIT);
> > >> #else
> > >>         printf("FP_64BIT not defined\n");
> > >> #endif
> > >>
> > >> #ifdef DIGIT_BIT
> > >>         printf("DIGIT_BIT: %d\n",DIGIT_BIT);
> > >> #else
> > >>         printf("DIGIT_BIT not defined\n");
> > >> #endif
> > >>
> > >> #ifdef CHAR_BIT
> > >>         printf("CHAR_BIT: %d\n",CHAR_BIT);
> > >> #else
> > >>         printf("CHAR_BIT not defined\n");
> > >> #endif
> > >>
> > >> #ifdef FP_MAX_SIZE
> > >>         printf("FP_MAX_SIZE: %d\n",FP_MAX_SIZE);
> > >> #else
> > >>         printf("FP_MAX_SIZE not defined\n");
> > >> #endif
> > >>
> > >> #ifdef FP_SIZE
> > >>         printf("FP_SIZE: %d\n",FP_SIZE);
> > >> #else
> > >>         printf("FP_SIZE not defined\n");
> > >> #endif
> > >>
> > >> #ifdef TFM_ASM
> > >>         printf("TFM_ASM: defined\n");
> > >> #else
> > >>         printf("TFM_ASM not defined\n");
> > >> #endif
> > >>
> > >>         exit(0);
> > >> }
> > >> ----
> > >>
> > >> The result was as follows.
> > >>
> > >> fp_digit: 8
> > >> unsigned long: 8
> > >> FP_64BIT not defined
> > >> DIGIT_BIT: 64
> > >> CHAR_BIT: 8
> > >> FP_MAX_SIZE: 8704
> > >> FP_SIZE: 136
> > >> TFM_ASM not defined
> > >>
> > >> Can you find a problem by this result?
> > >>
> > >> Thanks.
> > >>
> > >> --
> > >> T.Oyamada
> > >>
> > >> _______________________________________________
> > >> http://lurker.clamav.net/list/clamav-devel.html
> > >> Please submit your patches to our Bugzilla: http://bugs.clamav.net
> > >>
> > >
> > > I do not have an immediate fix, but that information does give me some
> > > leads.
> > >
> > > Basic issue: the tomsfastmath code must be falling through to the code
> > > block on lines 280-302 of fp_mul_comba.c.
> > > 1) The right shift causing the warning is DIGIT_BIT (64).
> > > 2) The datatype being shifted is fp_word.
> > > 3) fp_word defined as "typedef ulong64 fp_word;" from bignum_fast.h
> line
> > > 253
> > > 4) ulong64 defined as "typedef unsigned long long ulong64;" from
> > > bignum_fast.h line 248
> > >
> > > I think the problem is one of three issues:
> > > A) fp_word is not defined as a 64-bit datatype.
> > > B) line 301 of tomsfastmath/mul/fp_mul_comba.c is mistakenly
> downcasting t
> > > from fp_word to fp_digit before shifting.
> > > C) s390 is not allowing use of all 64 bits of fp_word.
> > >
> > > Problems A or B are easier fixed than C.
> > >
> > > Please add these lines to your test and re-run:
> > >
> > > printf("fp_word: %d\n",sizeof(fp_word));
> > > printf("ulong64: %d\n",sizeof(ulong64));
> > > printf("unsigned long long: %d\n",sizeof(unsigned long long));
> > > #ifdef CRYPT
> > >         printf("CRYPT: defined\n");
> > > #else
> > >         printf("CRYPT not defined\n");
> > > #endif
> > >
> > > I would like to see the config.log file generated by running
> configure. It
> > > would also be useful to have the full output from running make. The log
> > > snip shows line 91, but I expect that it first warned about line 15.
> > >
> > > The easiest way to continue and share logfiles is via Bugzilla. Please
> > > open a bug report on bugzilla.clamav.net on this issue. You can then
> > > attach the files to that bug.
> > >
> > > Hope this helps,
> > >
> > >
> > > Dave R.
> > >
> > > --
> > > ---
> > > Dave Raynor
> > > Sourcefire Vulnerability Research Team
> > > [email protected]
> > >
> >
> > I think I read something wrong, and I think I have an idea. It still
> needs
> > to be confirmed by the additional test lines above. Re-reading the
> output,
> > I think that the code is depending on fp_word being twice the size of
> > fp_digit. Based on fp_digit size of 8 that means it would expect it to be
> > 16. If sizeof(fp_word) is resolving to 8 and sizeof(fp_digit) is 8, that
> > could be the problem. Then the fix would depend on whether fp_word can be
> > made size 16 or must be constrained to size 8.
> >
> > Let me know what you find,
> >
> > Dave R.
> >
> > --
> > ---
> > Dave Raynor
> > Sourcefire Vulnerability Research Team
> > [email protected]
> > _______________________________________________
> > http://lurker.clamav.net/list/clamav-devel.html
> > Please submit your patches to our Bugzilla: http://bugs.clamav.net
> >
>
>
> _______________________________________________
> http://lurker.clamav.net/list/clamav-devel.html
> Please submit your patches to our Bugzilla: http://bugs.clamav.net
>

>From what I have read, gcc on s390 has a compiler option for setting the
size of "long double" type (64 or 128), but not "long long int". I expect
what we have to do instead is leave fp_word as 64 and tune down the
fp_digit to 32. That code block in bignum_fast.h is taken from tomsfastmath
and looks like it is aimed at 32-bit support anyway. This changes the
maximum ranges of the math calculations, but should be sufficient for our
needs (again, similar code runs on 32-bit).

Please try changing this line: (bignum_fast.h:line 252)
   typedef unsigned long      fp_digit;
to this line:
   typedef unsigned int      fp_digit;

If this is successful for you, we can determine the appropriate defines to
use to make this more portable.

Dave R.

-- 
---
Dave Raynor
Sourcefire Vulnerability Research Team
[email protected]
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