Andries:
Just to clarify, the old struct msqid_ds et. al are still used by all
Linux software before glibc 2.2. As of glibc 2.2, there is a new
user-level ABI for the SysV IPC functions {msg,sem,shm}*(), which provides
32-bit pids and 32-bit uids. All software using SysV IPC will need to be
recompiled under glibc 2.2 to take advantage of the new structures.
I don't think that returning incorrect pids to older programs here is
going to be any worse than returning incorrect uids or gids. But, we
should fix the kernel to return (-1) in 16 bits, or something like that,
in case of a pid overflow, to programs using the older structures.
-Chris Wing
wingc@engin.umich.edu
> (ii) There is also a rather obscure place in SYSV IPC where a 16-bit pid_t
> is used for the fields msg_lspid and msg_lrpid of the (obsolete)
> struct msqid_ds and the fields shm_cpid and shm_lpid of the (obsolete)
> struct shmid_ds. Nothing compiled today uses this, and almost nothing
> uses it at all, but this nevertheless means that one needs an option
> CONFIG_15BIT_PID (default=N) for backward binary compatibility.
>
> Andries
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Sep 30 2000 - 21:00:25 EST