Messages in this thread | | | Date | Wed, 8 Oct 2008 00:40:30 +0100 | From | Alan Cox <> | Subject | Re: [PATCH, v3] shmat: introduce flag SHM_MAP_NOT_FIXED |
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> > Can use shm_open and mmap to get POSIX standard shm behaviour via a sane > > I don't think shm_open can attach to SYSV shared segments. Or are you > proposing to add "sysvshmfs" to make that possible?
Actually you can do so. As it stands today the SYS3 SHM interface code does the following
create a char array in the form SYS%08ld, key open it on shmfs
> - There are legacy interfaces that cannot be really changed who use sysv shm > (e.g. X shm and others -- just do a ipcs on your system)
They can be changed and nobody is wanting to map those at fixed addresses.
> - An system call emulation as in qemu obviously has to implement the > existing system call semantics.
Which it can do perfectly well using shm_open to create its SYS3 SHM objects. In fact theoertically we could bin the whole of SYS3 shm and push it into glibc emulation if we wanted.
Alan
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