View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000593 | 1003.1(2008)/Issue 7 | System Interfaces | public | 2012-07-13 04:16 | 2024-06-11 08:52 |
| Reporter | eblake | Assigned To | ajosey | ||
| Priority | normal | Severity | Objection | Type | Omission |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Eric Blake | ||||
| Organization | Red Hat | ||||
| User Reference | ebb.posix_typed_mem_open | ||||
| Section | posix_typed_mem_open | ||||
| Page Number | 1515 | ||||
| Line Number | 48874 | ||||
| Interp Status | Approved | ||||
| Final Accepted Text | 0000593:0001319 | ||||
| Summary | 0000593: posix_typed_mem_open requires the use of <fcntl.h> | ||||
| Description | The posix_typed_mem_open interface is not usable without one of three O_* access modes from <fcntl.h> (line 48932). However, the <sys/mman.h> header is not required to define these constants, nor is it permitted to include symbols from <fcntl.h>. Furthermore, there is no portable historical value for these constants to allow programs to skip using the symbolic names (that is, O_RDONLY is 0 on some platforms and 1 elsewhere). Therefore, proper use of this interface requires inclusion of <fcntl.h>. Similar analysis applies to mq_open, sem_open, and shm_open, although at least <mqueue.h> and <semaphore.h> already permit optional inclusion of <fcntl.h>. Also, sem_open can be used without O_* constants, and therefore is a candidate for the <OH> shading of 0000591. The desired action presents three possible solutions; solutions one and two are adequate for TC2 of Issue 7, whereas solution three would be a new requirement that existing implementations do not meet (I specifically tested that glibc does NOT expose O_RDONLY in <sys/mman.h>), and therefore would need to be delayed to Issue 8. If the Austin Group decides to go with one of the first two solutions in the TC2 timeframe, it may still be worth cloning this bug to allow Issue 8 to go with solution three. | ||||
| Desired Action | Solution One: Mention the dependencies. After line 43622 (XSH mq_open SYNOPSIS), insert this line with MSG shading: <MSG>#include <fcntl.h></MSG> At line 43645 (XSH mq_open DESCRIPTION), change: values from the following list. to: values from the following list, defined in the <fcntl.h> header. After line 48874 (XSH posix_typed_mem_open SYNOPSIS), insert this line with TYM shading: <TYM>#include <fcntl.h></TYM> After line 58074 (XSH sem_open SYNOPSIS), insert this line with OH shading: <OH>#include <fcntl.h></OH> At line 58084 (XSH sem_open DESCRIPTION), change: The following flag bits may be set in oflag: to: The following flag bits, defined in <fcntl.h>, may be set in oflag: After line 60319 (XSH shm_open SYNOPSIS), insert this line with SHM shading: <SHM>#include <fcntl.h></SHM> Solution Two: Mention the dependencies, and permit but not require <sys/mman.h> to provide them. All changes in Solution One, plus these additional changes: After line 12468 (XBD <sys/mman.h> DESCRIPTION), insert the following paragraph, with TYM or SHM shading: <TYM|SHM>Inclusion of the <sys/mman.h> header may make visible all symbols from the <fcntl.h> header.</TYM|SHM> Solution Three: Require <mqueue.h>, <semaphore.h>, and <sys/mman.h> to be self-contained: After line 9854 (XBD <mqueue.h> DESCRIPTION), insert the following paragraph: The <mqueue.h> header shall define O_RDONLY, O_WRONLY, O_RDWR, O_CREAT, O_EXCL, and O_NONBLOCK as described in <fcntl.h>. After line 10879 (XBD <semaphore.h> DESCRIPTION), insert the following paragraph: The <semaphore.h> header shall define O_CREAT and O_EXCL as described in <fcntl.h>. After line 12468 (XBD <sys/mman.h> DESCRIPTION), insert the following paragraph, with TYM and SHM shading as marked: The <sys/mman.h> header shall define <TYM|SHM>O_RDONLY, O_RDWR</TYM|SHM>, <TYM>O_WRONLY</TYM>, <SHM>O_CREAT, O_EXCL, and O_TRUNC</SHM> as described in <fcntl.h>. After line 12485 (XBD <sys/mman.h> DESCRIPTION), insert the following paragraph: <TYM|SHM>Inclusion of the <sys/mman.h> header may make visible all symbols from the <fcntl.h> header.</TYM|SHM> At line 43645 (XSH mq_open DESCRIPTION), change: values from the following list. to: values from the following list, defined in the <mqueue.h> header. At line 48934 (XSH posix_typed_mem_open DESCRIPTION), change: defined in the <fcntl.h> header to: defined in the <sys/mman.h> header At line 58084 (XSH sem_open DESCRIPTION), change: The following flag bits may be set in oflag: to: The following flag bits, defined in <semaphore.h>, may be set in oflag: At line 60341 (XSH shm_open DESCRIPTION), change: defined in the <fcntl.h> header to: defined in the <sys/mman.h> header | ||||
| Tags | issue8 | ||||
| related to | 0000591 | Closed | ajosey | 1003.1(2008)/Issue 7 | No reason for OH margins in the synopses of open and creat |
| related to | 0000411 | Closed | ajosey | 1003.1(2008)/Issue 7 | adding atomic FD_CLOEXEC support |
| related to | 0000598 | Closed | ajosey | 1003.1(2008)/Issue 7 | OH shading and new interfaces |
| related to | 0001350 | Closed | Issue 8 drafts | O_* constants needed in <stdlib.h> for mkostemp() |
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The addition of O_CLOEXEC support in 0000411 will also impact solution 3. Also note that posix_openpt() uses O_RDWR and O_NOCTTY, but already requires the inclusion of <fcntl.h>, giving precedence to solution 1. Furthermore, <stdlib.h> (for posix_openpt) currently does not permit inclusion of <fcntl.h> (line 12042) and therefore does not give precedence to solution 2. |
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Interpretation response ------------------------ The standard states that <sys/mman.h> may not expose O_* constants, and conforming implementations must conform to this by also including <fcntl.h>. However, concerns have been raised about this which are being referred to the sponsor. Rationale: ------------- There is a desire to make headers self-contained for proper use of an interface. Notes to the Editor (not part of this interpretation): ------------------------------------------------------- Make the following edits (assuming that the edits in 0000411 will also be made): After line 9854 (XBD <mqueue.h> DESCRIPTION), insert the following paragraph: The <mqueue.h> header shall define O_RDONLY, O_WRONLY, O_RDWR, O_CREAT, O_EXCL, and O_NONBLOCK as described in <fcntl.h>. After line 10879 (XBD <semaphore.h> DESCRIPTION), insert the following paragraph: The <semaphore.h> header shall define O_CREAT and O_EXCL as described in <fcntl.h>. After line 11971 (XBD <stdlib.h> DESCRIPTION), insert the following paragraph with XSI shading: The <stdlib.h> header shall define O_CLOEXEC, O_NOCTTY, and O_RDWR as described in <fcntl.h>. At line 12042 (XBD <stdlib.h> DESCRIPTION), change: Inclusion of the <stdlib.h> header may also make visible all symbols from <stddef.h>, <limits.h>, <math.h>, and <sys/wait.h>. to this (still CX shaded): Inclusion of the <stdlib.h> header may also make visible all symbols from <fcntl.h>, <stddef.h>, <limits.h>, <math.h>, and <sys/wait.h>. After line 12468 (XBD <sys/mman.h> DESCRIPTION), insert the following paragraph, with TYM and SHM shading as marked: The <sys/mman.h> header shall define <TYM|SHM>O_RDONLY, O_RDWR</TYM|SHM>, <TYM>O_WRONLY, O_CLOEXEC</TYM>, <SHM>O_CREAT, O_EXCL, and O_TRUNC</SHM> as described in <fcntl.h>. After line 12485 (XBD <sys/mman.h> DESCRIPTION), insert the following paragraph: Inclusion of the <sys/mman.h> header may make visible all symbols from the <fcntl.h> header. At line 46459 (XSH posix_openpt SYNOPSIS), delete: #include <fcntl.h> At line 46467 (XSH posix_openpt DESCRIPTION), delete the phrase: defined in <fcntl.h> At line 48934 (XSH posix_typed_mem_open DESCRIPTION), delete the phrase: and defined in the <fcntl.h> header, At line 60341 (XSH shm_open DESCRIPTION), delete the phrase: defined in the <fcntl.h> header |
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Interpretation proposed 30 August 2012 for final 30 day review |
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Interpretation approved 29 Mar 2013 |
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When applying this bug I had to do the <sys/mman.h> change a little differently because the three different shadings have to be on separate lines. It looked best with all of the constants on separate lines (like the <stdlib.h> W* list). |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2012-07-13 04:16 | eblake | New Issue | |
| 2012-07-13 04:16 | eblake | Status | New => Under Review |
| 2012-07-13 04:16 | eblake | Assigned To | => ajosey |
| 2012-07-13 04:16 | eblake | Name | => Eric Blake |
| 2012-07-13 04:16 | eblake | Organization | => Red Hat |
| 2012-07-13 04:16 | eblake | User Reference | => ebb.posix_typed_mem_open |
| 2012-07-13 04:16 | eblake | Section | => posix_typed_mem_open |
| 2012-07-13 04:16 | eblake | Page Number | => 1515 |
| 2012-07-13 04:16 | eblake | Line Number | => 48874 |
| 2012-07-13 04:16 | eblake | Interp Status | => --- |
| 2012-07-13 04:16 | eblake | Relationship added | related to 0000591 |
| 2012-07-13 04:16 | eblake | Relationship added | related to 0000411 |
| 2012-07-13 04:21 | eblake | Note Added: 0001307 | |
| 2012-08-08 12:39 | eblake | Note Added: 0001319 | |
| 2012-08-08 13:23 | eblake | Relationship added | related to 0000598 |
| 2012-08-08 13:24 | eblake | Tag Attached: issue8 | |
| 2012-08-08 15:42 | eblake | Note Edited: 0001319 | |
| 2012-08-08 15:47 | msbrown | Note Edited: 0001319 | |
| 2012-08-08 15:48 | msbrown | Interp Status | --- => Pending |
| 2012-08-08 15:48 | msbrown | Final Accepted Text | => 0000593:0001319 |
| 2012-08-08 15:48 | msbrown | Status | Under Review => Interpretation Required |
| 2012-08-08 15:48 | msbrown | Resolution | Open => Accepted As Marked |
| 2012-08-30 09:20 | ajosey | Interp Status | Pending => Proposed |
| 2012-08-30 09:20 | ajosey | Note Added: 0001361 | |
| 2013-03-29 08:01 | ajosey | Interp Status | Proposed => Approved |
| 2013-03-29 08:01 | ajosey | Note Added: 0001508 | |
| 2020-05-19 10:44 | geoffclare | Note Added: 0004874 | |
| 2020-05-19 10:44 | geoffclare | Status | Interpretation Required => Applied |
| 2020-06-26 16:00 | geoffclare | Relationship added | related to 0001350 |
| 2024-06-11 08:52 | agadmin | Status | Applied => Closed |
