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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Is it possible C is the security problem? |
| Date | 2015-11-04 19:37 -0800 |
| Organization | None to speak of |
| Message-ID | <lnoaf95d68.fsf@kst-u.example.com> (permalink) |
| References | (2 earlier) <660e1300-4ef9-48a2-a170-86372552b4d6@googlegroups.com> <n1cnl1$il0$1@dont-email.me> <5985bb23-835e-4655-8f60-da3c6a99aa71@googlegroups.com> <n1e8ce$mki$1@dont-email.me> <8fc4438a-bdf9-4dd6-977c-0cb0d28e64c2@googlegroups.com> |
supercat@casperkitty.com writes:
> On Wednesday, November 4, 2015 at 6:40:07 PM UTC-6, Richard Heathfield wrote:
>> It is simply *not possible* for that code to overstep the bounds of the
>> array, and yet the overhead of bounds checking will be incurred, yes?
>> (If you disagree, I'd be fascinated to hear why.)
>
> Compilers which bundle their own getc() routine may be able to determine the
> range of values it can produce. Those which rely upon a getc() routine taken
> from elsewhere should expect that it might behave in "interesting" fashion
> and be prepared for that possibility. A programmer who's concerned about
> speed could write `++freq[(unsigned char)ch]`, in which case compilers would
> be able to recognize that the result was guaranteed to be in bounds.
The behavior of getc() is defined by the standard library, so a compiler
may assume that it behaves as specified (i.e., that it returns a value
that either is equal to EOF or is in the range 0..UCHAR_MAX).
Replacing getc() by a function that doesn't behave as the standard
requires causes undefined behavior if it's done by the programmer, or
non-conformance if it's done by the implementation.
[...]
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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Is it possible C is the security problem? G G <gdotone@gmail.com> - 2015-11-03 06:31 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 14:57 +0000
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-03 15:04 +0000
Re: Is it possible C is the security problem? G G <gdotone@gmail.com> - 2015-11-03 07:11 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 15:25 +0000
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-03 20:13 +0000
Re: Is it possible C is the security problem? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-03 15:18 -0500
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 20:34 +0000
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-03 22:47 +0000
Re: Is it possible C is the security problem? Udyant Wig <udyantw@gmail.com> - 2015-11-04 15:36 +0530
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 10:34 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-03 15:18 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-03 17:42 -0800
Re: Is it possible C is the security problem? Geoff <geoff@invalid.invalid> - 2015-11-03 15:32 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 23:57 +0000
Re: Is it possible C is the security problem? Geoff <geoff@invalid.invalid> - 2015-11-03 21:13 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 07:22 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-04 11:32 +0100
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 10:54 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-04 13:38 +0100
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-07 08:27 +0000
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-05 09:26 +0000
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-05 10:03 +0000
Re: Is it possible C is the security problem? James Kuyper <jameskuyper@verizon.net> - 2015-11-05 08:53 -0500
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-06 10:04 +0000
Re: Is it possible C is the security problem? Reinhardt Behm <rbehm@hushmail.com> - 2015-11-05 21:06 +0800
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-05 11:14 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-05 11:44 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-07 02:43 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-07 17:30 -0800
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-10 16:35 +0000
Re: Is it possible C is the security problem? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-10 11:52 -0500
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-11 00:48 -0600
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-17 21:55 +0000
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-17 19:14 -0600
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-18 03:40 +0000
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-17 23:01 -0600
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-18 09:00 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-18 09:09 -0800
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-18 15:35 -0600
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-18 21:35 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-18 20:38 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-19 05:40 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-18 22:55 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-19 19:56 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-18 23:40 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-19 21:05 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-19 06:40 -0800
Re: Is it possible C is the security problem? asetofsymbols@gmail.com - 2015-11-19 11:37 -0800
Re: Is it possible C is the security problem? asetofsymbols@gmail.com - 2015-11-19 12:09 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-19 12:52 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-20 12:20 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-19 15:34 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-22 16:43 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-21 21:28 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-22 20:51 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-22 07:26 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-22 09:42 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-22 09:59 -0800
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-23 07:08 +0000
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-23 11:57 +1300
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-22 16:06 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-23 13:26 +1300
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-19 09:09 +0000
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-20 02:29 -0800
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-20 12:33 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-20 09:26 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-19 13:37 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-19 14:07 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-20 01:38 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-19 18:43 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-20 12:09 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 01:48 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-20 11:16 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 05:04 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-20 18:18 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 11:55 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-21 00:27 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 18:57 -0800
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-20 19:50 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 20:06 -0800
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-20 20:46 -0800
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 20:56 -0800
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-21 04:58 -0600
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-21 04:59 -0800
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-21 13:26 -0600
Re: Is it possible C is the security problem? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-21 14:38 -0500
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-21 06:49 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 22:56 -0800
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-21 04:36 -0600
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-21 06:44 +0000
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-21 15:59 +0000
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-21 18:33 +0000
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-21 19:19 +0000
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-21 13:33 -0600
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-22 14:42 +0000
Re: Is it possible C is the security problem? Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-22 14:17 -0800
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-20 14:51 +1300
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-19 08:06 -0600
Re: Is it possible C is the security problem? Robert Wessel <robertwessel2@yahoo.com> - 2015-11-18 15:40 -0600
Re: Is it possible C is the security problem? Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-20 13:57 -0800
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-21 06:56 +0000
Re: Is it possible C is the security problem? Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-23 03:16 -0800
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-23 22:28 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-23 21:11 -0800
Re: Is it possible C is the security problem? Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-24 10:29 -0800
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-25 02:38 +0000
Re: Is it possible C is the security problem? Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-27 13:54 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-10 10:23 -0800
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-10 11:21 -0800
Re: Is it possible C is the security problem? Melzzzzz <mel@zzzzz.com> - 2015-11-04 00:58 +0100
Re: Is it possible C is the security problem? Les Cargill <lcargill99@comcast.com> - 2015-11-03 18:26 -0600
Re: Is it possible C is the security problem? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-11-04 02:06 +0000
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-04 14:12 +1300
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 07:02 +0000
Re: Is it possible C is the security problem? Ian Collins <ian-news@hotmail.com> - 2015-11-04 20:42 +1300
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 08:06 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-04 11:25 +0100
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-04 11:49 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-04 13:46 +0100
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-17 21:58 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-17 23:37 +0100
Re: Is it possible C is the security problem? David Thompson <dave.thompson2@verizon.net> - 2015-12-06 07:55 -0500
Re: Is it possible C is the security problem? Les Cargill <lcargill99@comcast.com> - 2015-12-06 14:23 -0600
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-03 15:59 +0000
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 16:55 +0000
Re: Is it possible C is the security problem? see.my.homepage@gmail.com - 2015-11-04 02:29 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-04 10:48 +0000
Re: Is it possible C is the security problem? see.my.homepage@gmail.com - 2015-11-04 14:11 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-05 00:39 +0000
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-05 01:15 +0000
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-05 02:02 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-04 18:31 -0800
Re: Is it possible C is the security problem? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-05 12:38 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-04 18:24 -0800
Re: Is it possible C is the security problem? Keith Thompson <kst-u@mib.org> - 2015-11-04 19:37 -0800
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-05 13:24 +0100
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-05 06:47 -0800
Re: Is it possible C is the security problem? see.my.homepage@gmail.com - 2015-11-05 00:35 -0800
Re: Is it possible C is the security problem? Richard Heathfield <rjh@cpax.org.uk> - 2015-11-05 09:55 +0000
Re: Is it possible C is the security problem? see.my.homepage@gmail.com - 2015-11-05 05:02 -0800
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-06 10:18 +0000
Re: Is it possible C is the security problem? see.my.homepage@gmail.com - 2015-11-06 05:57 -0800
Re: Is it possible C is the security problem? James Kuyper <jameskuyper@verizon.net> - 2015-11-04 08:32 -0500
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-03 15:01 +0000
Re: Is it possible C is the security problem? Bartc <bc@freeuk.com> - 2015-11-03 15:10 +0000
Re: Is it possible C is the security problem? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-03 11:02 -0500
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-03 18:13 +0000
Re: Is it possible C is the security problem? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-03 15:16 -0500
Re: Is it possible C is the security problem? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-11-04 09:38 +0000
Re: Is it possible C is the security problem? David Brown <david.brown@hesbynett.no> - 2015-11-04 11:38 +0100
Re: Is it possible C is the security problem? James Kuyper <jameskuyper@verizon.net> - 2015-11-03 11:58 -0500
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-03 09:13 -0800
Re: Is it possible C is the security problem? gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-03 18:08 +0000
Re: Is it possible C is the security problem? Nobody <nobody@nowhere.invalid> - 2015-11-04 04:49 +0000
Re: Is it possible C is the security problem? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-04 02:22 -0800
Re: Is it possible C is the security problem? gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-04 13:28 +0000
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-04 08:39 -0800
Re: Is it possible C is the security problem? John Bode <jfbode1029@gmail.com> - 2015-11-03 10:45 -0800
Re: Is it possible C is the security problem? supercat@casperkitty.com - 2015-11-03 11:05 -0800
Re: Is it possible C is the security problem? Les Cargill <lcargill99@comcast.com> - 2015-11-03 18:09 -0600
Is it possible C is the security problem? Chad <cdalten@gmail.com> - 2015-11-04 01:15 -0800
Re: Is it possible C is the security problem? gazelle@shell.xmission.com (Kenny McCormack) - 2015-11-04 13:31 +0000
Re: Is it possible C is the security problem? G G <gdotone@gmail.com> - 2015-11-18 10:55 -0800
Re: Is it possible C is the security problem? James Kuyper <jameskuyper@verizon.net> - 2015-11-18 14:05 -0500
Re: Is it possible C is the security problem? "D. Aaron Sawyer" <aaron@110.net> - 2015-11-18 19:47 -0500
Re: Is it possible C is the security problem? raltbos@xs4all.nl (Richard Bos) - 2015-11-20 10:43 +0000
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