Minutes of the 7 August 2014 Teleconference

[Andrew Josey]

All
Enclosed are the minutes of the 7 August 2014 Teleconference
regards
Andrew
----
Minutes of the 7 August 2014 Teleconference Austin-669 Page 1 of 1
Submitted by Andrew Josey, The Open Group. 8 August 2014

Attendees:
Andrew Josey, The Open Group
Richard Hansen, BBN
Don Cragun, IEEE PASC OR
Nick Stoughton, USENIX, ISO/IEC JTC 1/SC 22 OR
Geoff Clare, The Open Group
Joerg Schilling FOKUS Fraunhofer
Mark Ziegast, SHware Systems
David Clissold, IBM
Matthew Dempsky, OpenBSD
Mark Brown, Canonical
Eric Blake, Red Hat

Apologies
Martin Rehak, Oracle

* General news
Approval of the PAR within the PASC SEC is still stalled while some
procedural issues related to SEC membership are resolved.
Nick has an action to send Don the list of voting members of the SEC.

* Outstanding actions

+Bug 0000251: Forbid newline, or even bytes 1 through 31 (inclusive), in filenames OPEN
http://austingroupbugs.net/view.php?id=251
Don has an action to produce a proposal.

+Bug 0000561: NUL-termination of sun_path in Unix sockets OPEN
http://austingroupbugs.net/view.php?id=561
Eric has an action to update the proposal.

+Bug 0000573: Please add '+' to the portable filename character set OPEN
http://austingroupbugs.net/view.php?id=573
Joerg has an action to prepare a proposed change.

+Bug 0000592: consistent use of struct timespec OPEN
http://austingroupbugs.net/view.php?id=592
Jim had provided additional information in bugnote 1627.
This was discussed and Jim took an action to provide further information.

+Bug 0000598: OH shading and new interfaces OPEN
http://austingroupbugs.net/view.php?id=598
Eric has an action to propose a new solution with self-contained headers.

+Bug 0000517: EBNF support OPEN
http://austingroupbugs.net/view.php?id=517
Action on Joerg to look at this.

+Bug 0000633: SIGEV_THREAD delivery renders many signal interfaces unsafe
OPEN
http://austingroupbugs.net/view.php?id=633
We noted that feedback has settled down on the mailing list, and
will discuss next session.

+Bug 0000657: Conditions under which fmemopen() write a NUL to the buffer
are insufficiently specified OPEN
http://austingroupbugs.net/view.php?id=657
Eric has an action to propose wording to clarify the behavior for
fmemopen(), and also to contact the glibc developers to get their
feedback.

+Bug 0000658: Undefined/unspecified behavior clauses in description of
open have race conditions OPEN
http://austingroupbugs.net/view.php?id=658
It was noted that there is some overlap with changes in TC1. Eric took an
action to update the proposal to resolve the overlaps appropriately.

+Bug 0000615: pthread_setcancelstate should be async-signal-safe OPEN
http://austingroupbugs.net/view.php?id=615
We now have reports on AIX and Apple. Jim to report back on whether
pthread_cancelstate() is async-signal-safe on Solaris. Andrew to ask
HP whether pthread_cancelstate() is async-signal-safe on HP-UX.


+Bug 0000672: Necessary step(s) to synchronize filename operations on disk
OPEN
http://austingroupbugs.net/view.php?id=672

Geoff has a new proposed resolution in note 1618. Decided to solicit input
from FS developers. Eric to go to Linux, David to AIX and Jim to Solaris.
Jim has completed his action (see bugnote 1691).
Andrew should chase HP and Apple for input.

+Bug 0000663: Specification of str[n]casecmp is ambiguous reopened
http://austingroupbugs.net/view.php?id=663

Action on David to follow up with the IBM developers about the EBCDIC
collation sequence.

Bug 696 either NAME_MAX shouldn't be optional, or readdir_r() needs clarification
http://www.austingroupbugs.net/view.php?id=696

Don has an action to propose a resolution.

Bug 0000721: Internal storage vs static storage OPEN
http://austingroupbugs.net/view.php?id=721

This item is still open.

Bug 0000375: Extend test/[...] conditionals: ==, <, >, -nt, -ot, -ef OPEN
http://austingroupbugs.net/view.php?id=375

This is still left open due to discussions pending on the reflector.

Bug 0000789: Add set -o pipefail OPEN
http://austingroupbugs.net/view.php?id=789


* Current Business

We discussed C11 alignment. Matthew has posted a document
at
https://docs.google.com/a/dempsky.org/document/d/15lJFVak_anX_E6j96xp_juX6MbIhdodNTfQKeRNNBt8/edit

C11 has introduced thrreading and low level memory handling.
There have been different approaches to how to handle on POSIX systems.
It was agreed that it would be a good idea to develop a white paper
addressing alignment of POSIX systems with C11.
Andrew took an action to setup a separate reflector for the
topic - austin-c11-alignment.
(completed after the meeting)

Existing Austin Group participants can join the
new austin-c11-alignment list by accessing

https://collaboration.opengroup.org/platform/single_unix_specification/protected/mailinglists.php

This has the set of additional lists that Austin Group members
can self subscribe to (you will need to login first - in the left panel).


Bug #851: pthread_atfork orphans handlers in unloaded shared libraries OPEN
http://www.austingroupbugs.net/view.php?id=851

Action item: Andrew should try and contact to Finnbarr Murphy.
(Status: Andrew has sent a query to Finnbarr via linked.in)


Bug #852: Clarify MAP_FIXED semantics when replacing existing locked mappings Accepted as Marked
http://www.austingroupbugs.net/view.php?id=852

This item is tagged for TC2-2008

An interpretation is required.

Interpretation response:
The standard does not speak to this issue, and as such no conformance
distinction can be made between alternative implementations based
on this. This is being referred to the sponsor.

Rationale:
We believe this is a clarification of existing practice; removing
locks when remapping existing regions is important to applications
but the standard does not clearly specify what is supposed to happen
in this case.

Notes to the Editor (not part of this interpretation):

On page 1324 lines 43807-43808 (mmap() description), change:
If a MAP_FIXED request is successful, the mapping established
by mmap() replaces any previous mappings for the pages in the
range [pa,pa+len) of the process.
to:
If a MAP_FIXED request is successful, then any previous mappings
[ML|MLR]or memory locks[/] for those whole pages containing any
part of the address range [pa,pa+len) shall be removed, as if
by an appropriate call to munmap(), before the new mapping is
established.

On page 1326 lines 43928-43937 (mmap() rationale) change:
If an application requests a mapping that would overlay existing
mappings in the process, it might be desirable that an
implementation detect this and inform the application. However,
the default, portable (not MAP_FIXED) operation does not overlay
existing mappings. On the other hand, if the program specifies
a fixed address mapping (which requires some implementation
knowledge to determine a suitable address, if the function is
supported at all), then the program is presumed to be successfully
managing its own address space and should be trusted when it
asks to map over existing data structures. Furthermore, it is
also desirable to make as few system calls as possible, and it
might be considered onerous to require an munmap() before an
mmap() to the same address range. This volume of POSIX.1-2008
specifies that the new mappings replace any existing mappings,
following existing practice in this regard.
to:
If an application requests a mapping that overlaps existing
mappings in the process, it might be desirable that an
implementation detect this and inform the application. However,
if the program specifies a fixed address mapping (which requires
some implementation knowledge to determine a suitable address,
if the function is supported at all), then the program is
presumed to be successfully managing its own address space and
should be trusted when it asks to map over existing data
structures. Furthermore, it is also desirable to make as few
system calls as possible, and it might be considered onerous
to require an munmap() before an mmap() to the same address
range. This volume of POSIX.1-2008 specifies that the new mapping
replaces any existing mappings (implying an automatic munmap()
on the address range), following existing practice in this
regard. The standard developers also considered whether there
should be a way for new mappings to overlay existing mappings,
but found no existing practice for this.


On page 1328 line 43983 (mmap() rationale) change MEMLOCK_FUTURE to MCL_FUTURE.

Bug #854: requirement for additional built-in utilities to be searched for via $PATH was not and is not existing practice OPEN
http://austingroupbugs.net/view.php?id=854

Action: Andrew to ask David Korn to comment on this bug and the previous email discussion of the issue (seq 21270).



Bug #855: Tiny wording clarifications on "the" versus "a" startup file Accepted
http://austingroupbugs.net/view.php?id=855


Bug #857: Make rules which do not create the target file or do unexpected things with its timestamp OPEN
http://austingroupbugs.net/view.php?id=857

It was noted that case 1 is covered by
http://austingroupbugs.net/view.php?id=523

This item will be continued on the next call

Next Steps
----------
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--------
Andrew Josey The Open Group
Austin Group Chair Apex Plaza, Forbury Road
Email: a.josey-7882/***@public.gmane.org Reading,Berks.RG1 1AX,England
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Mobile:[phone] UK fax: [phone]