This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
for entire SYS5 SHM segments. This is totally unnecessary, and so the
correct allocation of VM objects has been substituted. (The vm_mmap
was misused -- vm_object_allocate is more appropriate.)
kern_fork.c: add the tiny bit of code for rfork operation.
kern/sysv_*: shmfork() takes one less arg, it was never used.
sys/shm.h: drop "isvfork" arg from shmfork() prototype
sys/param.h: declare rfork args.. (this is where OpenBSD put it..)
sys/filedesc.h: protos for fdshare/fdcopy.
vm/vm_mmap.c: add minherit code, add rounding to mmap() type args where
it makes sense.
vm/*: drop unused isvfork arg.
Note: this rfork() implementation copies the address space mappings,
it does not connect the mappings together. ie: once the two processes
have split, the pages may be shared, but the address space is not. If one
does a mmap() etc, it does not appear in the other. This makes it not
useful for pthreads, but it is useful in it's own right for having
light-weight threads in a static shared address space.
Obtained from: Original by Ron Minnich, extended by OpenBSD
int shmget(key_t key, int size, int shmflg);
If the 'key' has already existed in the system and set 'shmflg'
as '(IPC_CREAT|IPC_EXC)', then shmget() must return the error 'EEXIST'.
Submitted by: m_tanaka@pa.yokogawa.co.jp (Mihoko Tanaka)
Obtained from: NetBSD as well (He submitted it there too)
make sure that teh shm region is beyond the sum of the text and data segs
as it was big progs could collide with the shm region.
prototypes for all syscalls. The args structs are still declared in
comments as in VOP implementation functions. I don't like the
duplication for this, but several more layers of changes are required
to get it right. First we need to catch up with 4.4lite2, which uses
macros to handle struct padding. Then we need to catch up with NetBSD,
which passes the args correctly (as void *). Then we need to handle
varargs functions and struct padding better. I think all the details
can be hidden in machine-generated functions so that the args structs
and verbose macros to reference them don't have to appear in the core
sources.
Add prototypes.
Add bogus casts to hide the evil type puns exposed by the previous
steps. &uap[1] was used to get at the args after the first. This
worked because only the first arg in *uap was declared. This broke
when the machine- genenerated args struct declared all the args
(actually it declares extra args in some cases and depends on the
user stack having some accessible junk after the last arg, not to
mention the user args being on the stack. It isn't possible to
declare a correct args struct for a varargs syscall). The msgsys(),
semsys() and shmsys() syscall interfaces are BAD because they
multiplex several syscalls that have different types of args.
There was no reason to duplicate this sysv braindamage but now
we're stuck with it. NetBSD has reimplemented the syscalls properly
as separate syscalls #220-231.
Declare static functions as static in both their prototype and their
implementation (the latter is optional, and this misfeature was used).
Remove gratuitous #includes.
Continue cleaning up new init stuff.
external linkage.
Remove useless comments saying that SYSINIT() does system initialization.
shm.c:
Remove nearly useless comment that gave wrong pseudo-prototypes.
Submitted by: terry (terry lambert)
This is a composite of 3 patch sets submitted by terry.
they are:
New low-level init code that supports loadbal modules better
some cleanups in the namei code to help terry in 16-bit character support
some changes to the mount-root code to make it a little more
modular..
NOTE: mounting root off cdrom or NFS MIGHT be broken as I haven't been able
to test those cases..
certainly mounting root of disk still works just fine..
mfs should work but is untested. (tomorrows task)
The low level init stuff includes a total rewrite of init_main.c
to make it possible for new modules to have an init phase by simply
adding an entry to a TEXT_SET (or is it DATA_SET) list. thus a new module can
be added to the kernel without editing any other files other than the
'files' file.
