Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.c > #95146

Re: UB of memcpy(NULL, NULL, 0)

From Lőrinczy Zsigmond <nospam@for.me>
Newsgroups comp.lang.c
Subject Re: UB of memcpy(NULL, NULL, 0)
Date 2016-10-22 12:21 +0200
Organization Aioe.org NNTP Server
Message-ID <nufeig$1vtk$1@gioia.aioe.org> (permalink)
References <ntnodu$p8o$1@dont-email.me> <nu2pgp$gf2$1@gioia.aioe.org> <nucrn7$679$1@gioia.aioe.org> <caf46090-7044-41fe-ae8f-b425fa3e9732@googlegroups.com>

Show all headers | View raw


That might be very true, but not really relevant
when talking about the standard describing
function 'memcpy'

IMHO it could mention that reading from unreadable address,
or writing into unwriteable address is UB,
but that is true for every function dealing with pointers.

I think, important points would be these:

* if len==0, memcpy should do nothing
* if the from-area and to-area overlap, it is UB
* if from+len<from or to+len<to (address wrap-around), it is UB

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

UB of memcpy(NULL, NULL, 0) Noob <root@127.0.0.1> - 2016-10-13 12:42 +0200
  Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-13 11:55 +0100
    Re: UB of memcpy(NULL, NULL, 0) Noob <root@127.0.0.1> - 2016-10-13 13:09 +0200
      Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-13 12:22 +0100
        Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-13 12:22 -0700
          Re: UB of memcpy(NULL, NULL, 0) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-10-13 12:32 -0700
            Re: UB of memcpy(NULL, NULL, 0) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-10-13 12:34 -0700
    Re: UB of memcpy(NULL, NULL, 0) Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-10-13 08:24 -0600
      Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-13 16:22 +0100
      Re: UB of memcpy(NULL, NULL, 0) Noob <root@127.0.0.1> - 2016-10-13 17:49 +0200
        Re: UB of memcpy(NULL, NULL, 0) Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-10-13 12:02 -0600
  Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-15 20:56 +0200
    Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-15 12:52 -0700
    Re: UB of memcpy(NULL, NULL, 0) "James R. Kuyper" <jameskuyper@verizon.net> - 2016-10-15 15:55 -0400
    Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-15 13:41 -0700
      Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-16 11:17 +0200
        Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-16 10:26 +0100
        Re: UB of memcpy(NULL, NULL, 0) raltbos@xs4all.nl (Richard Bos) - 2016-10-16 09:55 +0000
          Re: UB of memcpy(NULL, NULL, 0) Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-16 08:44 -0400
            Re: UB of memcpy(NULL, NULL, 0) David Brown <david.brown@hesbynett.no> - 2016-10-17 10:06 +0200
              Re: UB of memcpy(NULL, NULL, 0) Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-17 09:06 -0400
                Re: UB of memcpy(NULL, NULL, 0) David Brown <david.brown@hesbynett.no> - 2016-10-17 16:29 +0200
                Re: UB of memcpy(NULL, NULL, 0) Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-17 17:05 -0400
                Re: UB of memcpy(NULL, NULL, 0) David Brown <david.brown@hesbynett.no> - 2016-10-18 11:19 +0200
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-18 08:04 -0700
                Re: UB of memcpy(NULL, NULL, 0) Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-18 16:27 -0400
            Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-17 08:59 -0700
              Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-17 11:21 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-17 13:42 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-17 14:46 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-17 15:52 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-17 16:43 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-18 08:00 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-18 09:14 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-18 09:43 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-18 11:31 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-18 12:49 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-18 12:03 -0700
              Re: UB of memcpy(NULL, NULL, 0) Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-17 17:06 -0400
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-17 14:55 -0700
        Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-16 11:23 -0700
      Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-17 08:49 -0700
        Re: UB of memcpy(NULL, NULL, 0) raltbos@xs4all.nl (Richard Bos) - 2016-10-18 16:54 +0000
          Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-18 11:09 -0700
            Re: UB of memcpy(NULL, NULL, 0) raltbos@xs4all.nl (Richard Bos) - 2016-10-23 13:24 +0000
              Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 09:28 -0700
              Re: UB of memcpy(NULL, NULL, 0) <william@wilbur.25thandClement.com> - 2016-10-29 11:32 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-29 14:12 -0700
    Re: UB of memcpy(NULL, NULL, 0) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-15 22:00 +0100
      Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-16 02:51 -0700
        Re: UB of memcpy(NULL, NULL, 0) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-16 11:20 +0100
          Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-16 04:14 -0700
            Re: UB of memcpy(NULL, NULL, 0) BartC <bc@freeuk.com> - 2016-10-16 12:22 +0100
            Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-16 13:01 +0100
              Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-16 05:29 -0700
                Re: UB of memcpy(NULL, NULL, 0) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-16 20:47 +0100
                Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-17 02:08 -0700
                Re: UB of memcpy(NULL, NULL, 0) David Brown <david.brown@hesbynett.no> - 2016-10-17 10:24 +0200
                Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-17 08:05 -0700
                Re: UB of memcpy(NULL, NULL, 0) David Brown <david.brown@hesbynett.no> - 2016-10-17 17:25 +0200
  Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-17 17:08 +0200
    Re: UB of memcpy(NULL, NULL, 0) Lorinczy Zsigmond <zsiga@nospam.for.me> - 2016-10-21 12:46 +0200
      Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-21 08:06 -0700
        Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-21 18:30 +0200
          Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-21 09:34 -0700
            Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-22 07:42 +0200
              Re: UB of memcpy(NULL, NULL, 0) James Kuyper <jameskuyper@verizon.net> - 2016-10-22 10:31 -0400
                Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-22 17:49 +0200
                Re: UB of memcpy(NULL, NULL, 0) Tim Rentsch <txr@alumni.caltech.edu> - 2016-10-22 13:43 -0700
                Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-23 07:47 +0200
                Re: UB of memcpy(NULL, NULL, 0) "James R. Kuyper" <jameskuyper@verizon.net> - 2016-10-23 11:07 -0400
                Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-23 17:45 +0200
                Re: UB of memcpy(NULL, NULL, 0) "James R. Kuyper" <jameskuyper@verizon.net> - 2016-10-23 12:16 -0400
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 07:38 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-24 08:38 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 09:44 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-23 12:22 -0700
                Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-23 13:37 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-23 14:15 -0700
                Re: UB of memcpy(NULL, NULL, 0) Ike Naar <ike@iceland.freeshell.org> - 2016-10-24 06:11 +0000
                Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-24 00:58 -0700
                Re: UB of memcpy(NULL, NULL, 0) Tim Rentsch <txr@alumni.caltech.edu> - 2016-10-23 14:07 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 07:48 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-24 08:40 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 10:03 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-24 12:06 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 13:36 -0700
                Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-24 13:57 -0700
                Re: UB of memcpy(NULL, NULL, 0) Tim Rentsch <txr@alumni.caltech.edu> - 2016-10-24 14:16 -0700
                Re: UB of memcpy(NULL, NULL, 0) supercat@casperkitty.com - 2016-10-24 17:23 -0700
                Re: UB of memcpy(NULL, NULL, 0) Tim Rentsch <txr@alumni.caltech.edu> - 2016-10-25 07:57 -0700
                Re: UB of memcpy(NULL, NULL, 0) James Kuyper <jameskuyper@verizon.net> - 2016-10-22 18:23 -0400
                Re: UB of memcpy(NULL, NULL, 0) "James R. Kuyper" <jameskuyper@verizon.net> - 2016-10-23 10:44 -0400
                Re: UB of memcpy(NULL, NULL, 0) Richard Heathfield <rjh@cpax.org.uk> - 2016-10-23 16:24 +0100
                Re: Verbing Noob <root@127.0.0.1> - 2016-10-23 18:02 +0200
        Re: UB of memcpy(NULL, NULL, 0) raltbos@xs4all.nl (Richard Bos) - 2016-10-23 13:26 +0000
          Re: UB of memcpy(NULL, NULL, 0) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-23 07:40 -0700
      Re: UB of memcpy(NULL, NULL, 0) asetofsymbols@gmail.com - 2016-10-21 23:56 -0700
        Re: UB of memcpy(NULL, NULL, 0) Lőrinczy Zsigmond <nospam@for.me> - 2016-10-22 12:21 +0200
          Re: UB of memcpy(NULL, NULL, 0) Keith Thompson <kst-u@mib.org> - 2016-10-22 16:33 -0700

csiph-web