Archived:Binary-incompatible change in Open C to require proper permission checks for creating IPC resources (Known Issue)

Article Metadata

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Tested with

Devices(s): All (S60 3rd Edition devices)

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Compatibility

Platform(s): S60 3rd Edition

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Article

Created: (20 Aug 2008)

Last edited: hamishwillee (18 Mar 2011)

Overview

To improve the performance and better adhere to POSIX standards, the next release of Open C will undergo some changes in the architecture. Some of the changes will also affect the binary compatibility with previous releases.

Description

Proper permissions must now be defined when creating IPC (inter-process communication) resources (shm, semaphore</tt, and <tt>msgqueue). The flag argument (value) can no longer be just IPC_CREAT. Specifying only IPC_CREAT means that the IPC resource is created with absolutely no permissions, and will result in EACCESS error.

How to reproduce

 int msgid;      
 struct msqid_ds buf = {0};
 msgid = msgget(1000, 512); /* returns with errno = 13 */

Solution

Starting from the next Open C release, IPC_CREAT has to be OR-ed with READ (0400) or/and WRITE (0200) permission.