Opened 7 years ago
Closed 7 years ago
#4364 closed defect (fixed)
[with patch, positive review] major bug in singular polynomial GCD (?)
Reported by: | was | Owned by: | malb |
---|---|---|---|
Priority: | major | Milestone: | sage-3.3 |
Component: | commutative algebra | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | Work issues: | ||
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by was)
This looks like maybe a serious bug in Singular's GCD:
On *32-bit* Linux or OS X we have this (it works fine on 64-bit):
sage: def f(n): ....: p = next_prime(n) ....: a = GF(p)(1) ....: b = GF(p)(1) ....: E = EllipticCurve([a, b]) ....: ret = E.multiplication_by_m(2) ....: return ret ....: sage: f(next_prime(2^30-41)) Program received signal SIGABRT, Aborted. [Switching to Thread -1210337072 (LWP 6522)] 0xffffe410 in __kernel_vsyscall () (gdb) (gdb) bt #0 0xffffe410 in __kernel_vsyscall () #1 0xb7de5df0 in raise () from /lib/tls/i686/cmov/libc.so.6 #2 0xb7de7641 in abort () from /lib/tls/i686/cmov/libc.so.6 #3 0xb7b6ff12 in global_NTL_error_callback (s=0xb7a3c8c8 "zz_pContext: modulus too big", context=0x0) at src/stdsage.c:42 #4 0xb79f9ef7 in NTL::Error (s=0xb7a3c8c8 "zz_pContext: modulus too big") at tools.c:38 #5 0xb79a26db in zz_pInfoT (this=0xa1be668, NewP=1073741827, maxroot=25) at lzz_p.c:15 #6 0xb79a280e in zz_pContext (this=0xbfa40744, p=1073741827, maxroot=25) at lzz_p.c:157 #7 0xb47649c5 in gcd_poly_p (f=@0xbfa40908, g=@0xbfa40904) at cf_gcd.cc:852 #8 0xb47660b8 in gcd_poly (f=@0xbfa40b4c, g=@0xbfa40b50) at cf_gcd.cc:538 #9 0xb4766ca3 in gcd (f=@0xbfa40b4c, g=@0xbfa40b50) at cf_gcd.cc:776 #10 0xb45dd1f1 in singclap_gcd (f=0xb445e220, g=0xb445e324) at clapsing.cc:230 #11 0xb4849286 in __pyx_pf_4sage_5rings_10polynomial_28multi_polynomial_libsingular_23MPolynomial_libsingular_gcd (__pyx_v_self=0xb7c80acc, __pyx_args=0xa1d158c, __pyx_kwds=0x0) at sage/rings/polynomial/multi_polynomial_libsingular.cpp:23491
Attachments (1)
Change History (6)
comment:1 Changed 7 years ago by mabshoff
comment:2 Changed 7 years ago by was
- Description modified (diff)
comment:3 Changed 7 years ago by malb
- Summary changed from major bug in singular polynomial GCD (?) to [with patch, needs review] major bug in singular polynomial GCD (?)
Changed 7 years ago by malb
comment:4 Changed 7 years ago by was
- Summary changed from [with patch, needs review] major bug in singular polynomial GCD (?) to [with patch, positive review] major bug in singular polynomial GCD (?)
comment:5 Changed 7 years ago by mabshoff
- Milestone changed from sage-3.4.1 to sage-3.3
- Resolution set to fixed
- Status changed from new to closed
Merged in Sage 3.3.alpha3.
Cheers,
Michael
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This is actually an uncaught error in NTL:
This then likely segfaults libSingular.
Cheers,
Michael