Commit Graph

64 Commits

Author SHA1 Message Date
Alan Cox
d4da2dbae6 Fix the following problem:
When creating new processes (or performing exec), the new page
directory is initialized too early.  The kernel might grow before
p_vmspace is initialized for the new process.  Since pmap_growkernel
doesn't yet know about the new page directory, it isn't updated, and
subsequent use causes a failure.

The fix is (1) to clear p_vmspace early, to stop pmap_growkernel
from stomping on memory, and (2) to defer part of the initialization
of new page directories until p_vmspace is initialized.

PR:		kern/12378
Submitted by:	tegge
Reviewed by:	dfr
1999-07-21 18:02:27 +00:00
Peter Wemm
1943af613f Stop rfork(0) from panicing. (oops!!)
Submitted by:	Peter Holm <peter@holm.cc>
1999-07-03 20:58:44 +00:00
Peter Wemm
df8abd0bb9 Slight tweak to fork1() calling conventions. Add a third argument so
the caller can easily find the child proc struct.  fork(), rfork() etc
syscalls set p->p_retval[] themselves.  Simplify the SYSINIT_KT() code
and other kernel thread creators to not need to use pfind() to find the
child based on the pid.  While here, partly tidy up some of the fork1()
code for RF_SIGSHARE etc.
1999-06-30 15:33:41 +00:00
Poul-Henning Kamp
75c1354190 This Implements the mumbled about "Jail" feature.
This is a seriously beefed up chroot kind of thing.  The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.

For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact:  "real virtual servers".

Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.

Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.

It generally does what one would expect, but setting up a jail
still takes a little knowledge.

A few notes:

   I have no scripts for setting up a jail, don't ask me for them.

   The IP number should be an alias on one of the interfaces.

   mount a /proc in each jail, it will make ps more useable.

   /proc/<pid>/status tells the hostname of the prison for
   jailed processes.

   Quotas are only sensible if you have a mountpoint per prison.

   There are no privisions for stopping resource-hogging.

   Some "#ifdef INET" and similar may be missing (send patches!)

If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!

Tools, comments, patches & documentation most welcome.

Have fun...

Sponsored by:   http://www.rndassociates.com/
Run for almost a year by:       http://www.servetheweb.com/
1999-04-28 11:38:52 +00:00
Luoqi Chen
5206bca10a Enable vmspace sharing on SMP. Major changes are,
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
  is added to point to per-cpu pages, per-cpu global variables are now
  accessed through this new selector (%fs). The selectors in gdt table are
  rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		John Dyson	<dyson@iquest.net>
		Julian Elischer	<julian@whistel.com>
		Bruce Evans	<bde@zeta.org.au>
		David Greenman	<dg@root.com>
1999-04-28 01:04:33 +00:00
Dmitrij Tejblum
0dd9741eb4 Use pointer arithmetic to do pointer arithmetic. 1999-04-24 11:25:01 +00:00
Peter Wemm
e91896117b Well folks, this is it - The second stage of the removal for build support
for LKM's..
1999-04-17 08:36:07 +00:00
Peter Wemm
af8ad83e5c Use the reference-counted PHOLD()/PRELE() rather than P_NOSWAP. 1999-04-06 03:03:34 +00:00
Julian Elischer
4ac9ae7083 Fix thread/process tracking and differentiation for Linux threads emulation.
Submitted by:	Richard Seaman, Jr." <dick@tar.com>

Also clean some compiler warnings in surrounding code.
1999-03-02 00:28:09 +00:00
Julian Elischer
88c5ea4574 Enable Linux threads support by default.
This takes the conditionals out of the code that has been tested by
various people for a while.
ps and friends (libkvm) will need a recompile as some proc structure
changes are made.

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-26 02:38:12 +00:00
Julian Elischer
dc9c271aa1 Changes to the LINUX_THREADS support to only allocate extra memory for
shared signal handling when there is shared signal handling being
used.

This removes the main objection to making the shared signal handling
a standard ability in rfork() and friends and 'unconditionalising'
this code. (i.e. the allocation of an extra 328 bytes per process).

Signal handling information remains in the U area until such a time as
it's reference count would be incremented to > 1. At that point a new
struct is malloc'd and maintained in KVM so that it can be shared between
the processes (threads) using it.

A function to check the reference count and move the struct back to the U
area when it drops back to 1 is also supplied. Signal information is
therefore now swapable for all processes that are not sharing that
information with other processes. THis should addres the concerns raised
by Garrett and others.

Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1999-01-07 21:23:50 +00:00
Julian Elischer
6626c6045c Reviewed by: Luoqi Chen, Jordan Hubbard
Submitted by:	 "Richard Seaman, Jr." <lists@tar.com>
Obtained from:	linux :-)

Code to allow Linux Threads to run under FreeBSD.

By default not enabled
This code is dependent on the conditional
COMPAT_LINUX_THREADS (suggested by Garret)
This is not yet a 'real' option but will be within some number of hours.
1998-12-19 02:55:34 +00:00
Don Lewis
643a8daaaf If the session leader dies, s_leader is set to NULL and getsid() may
dereference a NULL pointer, causing a panic.  Instead of following
s_leader to find the session id, store it in the session structure.

Jukka found the following info:

	BTW - I just found what I have been looking for. Std 1003.1
	Part 1: SYSTEM API [C LANGUAGE] section 2.2.2.80 states quite
	explicitly...

	Session lifetime: The period between when a session is created
	and the end of lifetime of all the process groups that remain
	as members of the session.

	So, this quite clearly tells that while there is any single
	process in any process group which is a member of the session,
	the session remains as an independent entity.

Reviewed by:	peter
Submitted by:	"Jukka A. Ukkonen" <jau@jau.tmt.tele.fi>
1998-11-09 15:08:04 +00:00
John Dyson
2d8acc0f4a VM level code cleanups.
1)	Start using TSM.
	Struct procs continue to point to upages structure, after being freed.
	Struct vmspace continues to point to pte object and kva space for kstack.
	u_map is now superfluous.
2)	vm_map's don't need to be reference counted.  They always exist either
	in the kernel or in a vmspace.  The vmspaces are managed by reference
	counts.
3)	Remove the "wired" vm_map nonsense.
4)	No need to keep a cache of kernel stack kva's.
5)	Get rid of strange looking ++var, and change to var++.
6)	Change more data structures to use our "zone" allocator.  Added
	struct proc, struct vmspace and struct vnode.  This saves a significant
	amount of kva space and physical memory.  Additionally, this enables
	TSM for the zone managed memory.
7)	Keep ioopt disabled for now.
8)	Remove the now bogus "single use" map concept.
9)	Use generation counts or id's for data structures residing in TSM, where
	it allows us to avoid unneeded restart overhead during traversals, where
	blocking might occur.
10)	Account better for memory deficits, so the pageout daemon will be able
	to make enough memory available (experimental.)
11)	Fix some vnode locking problems. (From Tor, I think.)
12)	Add a check in ufs_lookup, to avoid lots of unneeded calls to bcmp.
	(experimental.)
13)	Significantly shrink, cleanup, and make slightly faster the vm_fault.c
	code.  Use generation counts, get rid of unneded collpase operations,
	and clean up the cluster code.
14)	Make vm_zone more suitable for TSM.

This commit is partially as a result of discussions and contributions from
other people, including DG, Tor Egge, PHK, and probably others that I
have forgotten to attribute (so let me know, if I forgot.)

This is not the infamous, final cleanup of the vnode stuff, but a necessary
step.  Vnode mgmt should be correct, but things might still change, and
there is still some missing stuff (like ioopt, and physical backing of
non-merged cache files, debugging of layering concepts.)
1998-01-22 17:30:44 +00:00
John Dyson
74b2192ae6 We have had support for running the kernel daemons as threads for
quite a while, but forgot to do so.  For now, this code supports
most daemons  running as kernel threads in UP kernels, and as
full processes in SMP.  We will soon be able to run them as
threads in SMP, but not yet.
1997-12-12 04:00:59 +00:00
Bruce Evans
be67169a57 Removed unused includes.
Staticized.

Avoid passing a `retval' to fork1().

Fixed some style bugs.
1997-11-20 16:36:17 +00:00
Poul-Henning Kamp
cb226aaa62 Move the "retval" (3rd) parameter from all syscall functions and put
it in struct proc instead.

This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.

I have not removed the /*ARGSUSED*/, they will require some looking at.

libkvm, ps and other userland struct proc frobbing programs will need
recompiled.
1997-11-06 19:29:57 +00:00
Bruce Evans
eb776aea19 Fixed some gratuitous ANSIisms. 1997-08-26 00:15:04 +00:00
Peter Wemm
e384a9801e Print a warning if an unsupported (under SMP) shared address space fork
is attempted rather than just failing with an errno.
1997-08-22 15:10:00 +00:00
John Dyson
2244ea07dc This is an upgrade so that the kernel supports the AIO calls from
POSIX.4.  Additionally, there is some initial code that supports LIO.
This code supports AIO/LIO for all types of file descriptors, with
few if any restrictions.  There will be a followup very soon that
will support significantly more efficient operation for VCHR type
files (raw.)  This code is also dependent on some kernel features
that don't work under SMP yet.  After I commit the changes to the
kernel to support proper address space sharing on SMP, this code
will also work under SMP.
1997-07-06 02:40:43 +00:00
Peter Wemm
b3196e4b9f Preliminary support for per-cpu data pages.
This eliminates a lot of #ifdef SMP type code.  Things like _curproc reside
in a data page that is unique on each cpu, eliminating the expensive macros
like:    #define curproc (SMPcurproc[cpunumber()])

There are some unresolved bootstrap and address space sharing issues at
present, but Steve is waiting on this for other work.  There is still some
strictly temporary code present that isn't exactly pretty.

This is part of a larger change that has run into some bumps, this part is
standalone so it should be safe.  The temporary code goes away when the
full idle cpu support is finished.

Reviewed by: fsmp, dyson
1997-06-22 16:04:22 +00:00
John Dyson
2c1011f7ef Modifications to existing files to support the initial AIO/LIO and
kernel based threading support.
1997-06-16 00:29:36 +00:00
Peter Wemm
8f453f3ed3 Don't need "opt_smp.h" on these files 1997-05-29 04:52:04 +00:00
Peter Wemm
c76e95c3c7 Create sysctl kern.fast_vfork, on for uniprocessor by default, off for
SMP.
1997-04-26 15:59:50 +00:00
Peter Wemm
c32ba2484e Disable RFMEM in vfork for smp case.. It doesn't seem to work too well
yet..
1997-04-26 14:31:36 +00:00
Andrey A. Chernov
0eaa559cbf Restore memory space separation (RFMEM) for vfork() after
shell imgact memory clobbering fixed
1997-04-23 22:13:18 +00:00
John Dyson
6b707440d3 Give up on the fast vfork() for a while. 1997-04-23 01:59:14 +00:00
John Dyson
c58494e476 Re-institute the efficent version of vfork. It appears to make a
difference of approx 3mins in make world on my P6!!!  This means
that vfork now has full address space sharing, so beware with
sloppy vfork programming.  Also, you really do need to apply
the previously committed popen fix in libc.
1997-04-20 16:57:12 +00:00
John Dyson
d7f7f3f20e Make a problem that I cannot reproduce go away for now. This commit
is to decrease the inconvienience of other developers until I can
really fix the code.
Reviewed by:	Donald J. Maddox <dmaddox@scsn.net>
1997-04-14 01:28:58 +00:00
John Dyson
5856e12e69 Fully implement vfork. Vfork is now much much faster than even our
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)

Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
	from the other threads of a group.

Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
	possible existing shares with other threads/processes.

Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
	thread from the rest of the group.

Fix the case where a thread does an exec.  It is almost nonsense for a thread
	to modify the other threads address space by an exec, so we
	now automatically divorce the address space before modifying it.
1997-04-13 01:48:35 +00:00
Peter Wemm
263a339213 Remove explicit zero of p_vmspace on creation, it's now in the startzero
section of the proc struct.
1997-04-07 09:38:39 +00:00
Peter Wemm
a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
David Greenman
70e534e78f Pass P_SUGID on to the child of a fork(). It was possible to get rlogin
to coredump previously since it (somewhat uniquely) is setuid and forks
without execing, and thus without passing P_SUGID the child could
coredump and possibly divulge sensitive information (such as encrypted
passwords from the passwd database).
1997-02-17 10:58:46 +00:00
John Dyson
996c772f58 This is the kernel Lite/2 commit. There are some requisite userland
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
		Mount_std mounts will not work until the getfsent
		library routine is changed.

Reviewed by:	various people
Submitted by:	Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
Bruce Evans
3e2bca9e04 Fixed interrupt unmasking for child processes which I broke in
rev.1.10 two years ago.  Children continued to run at splhigh()
after returning from vm_fork().  This mainly affected kernel
processes and init.  For ordinary processes, interrupts are normally
unmasked a few instructions later after fork() returns (it may be
important for syscall() not to reschedule the child processes).
Kernel processes had workarounds for the problem.  Init manages to
start because some routines "know" that it is safe to go to sleep
despite their caller starting them at a high ipl.  Then its ipl
gets fixed on its first normal return from a syscall.
1997-01-15 18:58:42 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
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.
1997-01-14 07:20:47 +00:00
Wolfram Schneider
510681905e Move static variable nextpid out from fork1(). Now top(1) can print
last pid value.
1996-10-27 13:29:22 +00:00
Bruce Evans
b71fec07db Eliminated nested include of <sys/unistd.h> in <sys/file.h> in the kernel.
Include it directly in the few places where it is used.

Reduced some #includes of <sys/file.h> to #includes of <sys/fcntl.h> or
nothing.
1996-09-03 14:25:27 +00:00
Julian Elischer
e0d898b48e Some cleanups to the callout lists recently added.
note that at_shutdown has a new parameter to indicate When
during a shutdown the callout should be made. also
add a RB_POWEROFF flag to reboot "howto" parameter..
tells the reboot code in our at_shutdown module to turn off the UPS
and kill the power. bound to be useful eventually on laptops
1996-08-22 03:50:33 +00:00
Julian Elischer
fed06968ba add callout lists for exit() and fork()
I've been meaning to do this for AGES as I keep having to patch those routines
whenever I write a proprietary package or similar..

any module that assigns resources to processes needs to know when
these events occur. there are existsing modules that should be modified
to take advantage of these.. e.g. SYSV IPC primatives
presently have #ifdef entries in exit()


this also helps with making LKMs out of such things..

(see the man pages at_exit(9) and at_fork(9))
1996-08-19 02:28:24 +00:00
David Greenman
b1508c72f4 Converted timer/run queues to 4.4BSD queue style. Removed old and unused
sleep(). Implemented wakeup_one() which may be used in the future to combat
the "thundering herd" problem for some special cases.

Reviewed by:	dyson
1996-07-31 09:26:54 +00:00
Gary Palmer
c23670e294 Clean up -Wunused warnings.
Reviewed by:		bde
1996-06-12 05:11:41 +00:00
Peter Wemm
88d1b64235 Fix a nasty bug that causes random crashes and lockups particularly on
very busy servers (eg: news, web).  This is an interaction between
embryonic processes that have not yet finished forking, and happen to
cause the kernel VM space to grow, hitting the uninitialised variable.

It was possible for this to strike at any time, depending on the size of
your kernel and load patterns.  One machine had paniced occasionally
when cron launches a job since before the 2.1 release.

If you had "options DIAGNOSTIC", you may have seen references to bogus
addresses like 0xdeadc142 and the like.

This is a minimal change to fix the problem, it will probably be done
better by reordering p_vmspace to be in the startzero section, but it
becomes harder to validate then.

It's been vulnerable since pmap.c rev 1.40 (Jan 9, 1995), so it's been a
cause of problems since well before 2.0.5.  This was when the merged
VM/buffer cache and the dynamic growing kernel VM space were first
committed.  This probably fixes a few of PR's.
1996-05-02 11:38:05 +00:00
Sujal Patel
0e3eb7ee6c Implement the RFNOWAIT flag for rfork(). If set this flag will cause the
forked child to be dissociated from the parent).

Cleanup fork1(), implement vfork() and fork() in terms of rfork() flags.

Remove RFENVG, RFNOTEG, RFCNAMEG, RFCENVG which are Plan9 specific and cannot
possibly be implemented in FreeBSD.

Renumbered the flags to make up for the removal of the above flags.

Reviewed by:	peter, smpatel
Submitted by:	Mike Grupenhoff <kashmir@umiacs.umd.edu>
1996-04-17 17:05:08 +00:00
Jeffrey Hsu
b75356e1ac From Lite2: proc LIST changes.
Reviewed by:	david & bde
1996-03-11 06:05:03 +00:00
John Dyson
ef5dc8a96d Keep fork from over extending the number of processes. Since u_map is
sized exactly for maxproc, the occasional overrunning the maxproc limit
can cause problems.
1996-03-03 19:48:45 +00:00
Peter Wemm
dabee6fecc kern_descrip.c: add fdshare()/fdcopy()
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
1996-02-23 18:49:25 +00:00
Garrett Wollman
db6a20e23e Converted two options over to the new scheme: USER_LDT and KTRACE. 1996-01-03 21:42:35 +00:00
David Greenman
efeaf95a41 Untangled the vm.h include file spaghetti. 1995-12-07 12:48:31 +00:00