Interpretations

Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretation for IEEE Std 1003.1™-1990 IEEE Standard for Information Technology--Portable Operating System Interfaces (POSIX®)

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Interpretation Request #115
Topic:
mprotect v mmap Relevant Sections: 12.2.3.2 , 12.2.1.2, p272 line 220, p278 line 416 PASC

It would appear that the two paragraphs should be saying the same thing (identically) and they do not, particularly the bit about the _POSIX_MEMORY_PROTECTION option.

At least reconcile the two paragraphs. However, it would be better to remove the duplication (by moving it to a section of general concepts) and refer to the resultant text there. (I suspect that one or the other paragraphs (probably the one at 23167) is correct as it stands.)

Interpretation Response
The standard is clear; _POSIX_MEMORY_PROTECTION covers all of mprotect but only part of mmap. No change is required.

Rationale for Interpretation
None. Forwarded to Interpretations group: 19 June 2000 Proposed resolution: 25 July 2000 Finalised interpretation: 29 August 2000 [note, not part of this interpretation: an observation on 10 above, one reason they do not have a statement about the Memory Protection option in mprotect() is that the whole function is only supported in .1-1996 when the option is supported, hence specifying semantics in that case makes no sense]