machine
Assume that a vnode (and associated data structures) costs 2kB in the
worst imaginable case. Don't allow sysctl to set desiredvnodes to a
value that would use more than 75% of KVA or 75% of physical memory.
we no longer need to guard against access from hardware interrupt handlers.
Additionally, if cloning a process with CLONE_SIGHAND, arrange to have the
child process share the parent's lock so that signal state may be kept in
sync. Partially addresses PR kern/37437.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
- Add a KAUTH_PROCESS_SCHEDULER action, to handle scheduler related
requests, and add specific requests for set/get scheduler policy and
set/get scheduler parameters.
- Add a KAUTH_PROCESS_KEVENT_FILTER action, to handle kevent(2) related
requests.
- Add a KAUTH_DEVICE_TTY_STI action to handle requests to TIOCSTI.
- Add requests for the KAUTH_PROCESS_CANSEE action, indicating what
process information is being looked at (entry itself, args, env,
open files).
- Add requests for the KAUTH_PROCESS_RLIMIT action indicating set/get.
- Add requests for the KAUTH_PROCESS_CORENAME action indicating set/get.
- Make bsd44 secmodel code handle the newly added rqeuests appropriately.
All of the above make it possible to issue finer-grained kauth(9) calls in
many places, removing some KAUTH_GENERIC_ISSUSER requests.
- Remove the "CAN" from KAUTH_PROCESS_CAN{KTRACE,PROCFS,PTRACE,SIGNAL}.
Discussed with christos@ and yamt@.
- Lock processes, credentials, filehead etc correctly.
- Acquire a read hold on sysctl_treelock if only doing a query.
- Don't wire down the output buffer. It doesn't work correctly and the code
regularly does long term sleeps with it held - it's not worth it.
- Don't hold locks other than sysctl_lock while doing copyout().
- Drop sysctl_lock while doing copyout / allocating memory in a few places.
- Don't take kernel_lock for sysctl.
- Fix a number of bugs spotted along the way
For regular (non PIE) executables randomization is enabled for:
1. The data segment
2. The stack
For PIE executables(*) randomization is enabled for:
1. The program itself
2. All shared libraries
3. The data segment
4. The stack
(*) To generate a PIE executable:
- compile everything with -fPIC
- link with -shared-libgcc -Wl,-pie
This feature is experimental, and might change. To use selectively add
options PAX_ASLR=0
in your kernel.
Currently we are using 12 bits for the stack, program, and data segment and
16 or 24 bits for mmap, depending on __LP64__.
- Don't ignore return value of settime() in sysctl_kern_rtc_offset(), as
suggested by yamt@.
Note: the kauth(9) call in sysctl_kern_rtc_offset() is bogus, but this will
be addressed separately.
tech-kern:
- Invert priority space so that zero is the lowest priority. Rearrange
number and type of priority levels into bands. Add new bands like
'kernel real time'.
- Ignore the priority level passed to tsleep. Compute priority for
sleep dynamically.
- For SCHED_4BSD, make priority adjustment per-LWP, not per-process.
by deleting arguments. This is a popular practice, and failing means that
ps(1) prints (programname). For example this is what XtOpenDisplay() with
-geometry. This used to work before 2.0H, and the behavior is allowed and
hinted by POSIX. Found out by Anon Ymous.
can copy directly to/from userspace.
Avoids exposing the implementation of the group list as an array to code
outside kern_auth.c.
compat code and man page need updating.
from doc/BRANCHES:
idle lwp, and some changes depending on it.
1. separate context switching and thread scheduling.
(cf. gmcgarry_ctxsw)
2. implement idle lwp.
3. clean up related MD/MI interfaces.
4. make scheduler(s) modular.
I think it existed to cache the numbers in kernel memory of a zombie when
proc->p_stats was part of the 'u' area - so got freed earlier and wouldn't
(easily) be accessible from a separate process. However since both the
p_ru and p_stats fields are freed at the same time it is no longer needed.
Ride the recent 4.99.19 version change.
P_*/L_* naming convention, and rename the in-kernel flags to avoid
conflict. (P_ -> PK_, L_ -> LW_ ). Add back the (now unused) LSDEAD
constant.
Restores source compatibility with pre-newlock2 tools like ps or top.
Reviewed by Andrew Doran.
In 30 minutes from now Jason Thorpe will come up with an implementation
of a proplib dictionary in struct proc, so adding an int doesn't really
make any sense.
assumed that all the strings were stored in a row, separated by NUL chars,
at the address pointed bu argv[0] (or envp[0]).
This was wrong: if the program changed argvs[0], we still read the
first string correctly, but the next strings did contain unexpected data.
The fix: read the whole argv (or envp) array, then copy the string one by
one, using their addresses in argv (or agrp)
- Add a few scopes to the kernel: system, network, and machdep.
- Add a few more actions/sub-actions (requests), and start using them as
opposed to the KAUTH_GENERIC_ISSUSER place-holders.
- Introduce a basic set of listeners that implement our "traditional"
security model, called "bsd44". This is the default (and only) model we
have at the moment.
- Update all relevant documentation.
- Add some code and docs to help folks who want to actually use this stuff:
* There's a sample overlay model, sitting on-top of "bsd44", for
fast experimenting with tweaking just a subset of an existing model.
This is pretty cool because it's *really* straightforward to do stuff
you had to use ugly hacks for until now...
* And of course, documentation describing how to do the above for quick
reference, including code samples.
All of these changes were tested for regressions using a Python-based
testsuite that will be (I hope) available soon via pkgsrc. Information
about the tests, and how to write new ones, can be found on:
http://kauth.linbsd.org/kauthwiki
NOTE FOR DEVELOPERS: *PLEASE* don't add any code that does any of the
following:
- Uses a KAUTH_GENERIC_ISSUSER kauth(9) request,
- Checks 'securelevel' directly,
- Checks a uid/gid directly.
(or if you feel you have to, contact me first)
This is still work in progress; It's far from being done, but now it'll
be a lot easier.
Relevant mailing list threads:
http://mail-index.netbsd.org/tech-security/2006/01/25/0011.htmlhttp://mail-index.netbsd.org/tech-security/2006/03/24/0001.htmlhttp://mail-index.netbsd.org/tech-security/2006/04/18/0000.htmlhttp://mail-index.netbsd.org/tech-security/2006/05/15/0000.htmlhttp://mail-index.netbsd.org/tech-security/2006/08/01/0000.htmlhttp://mail-index.netbsd.org/tech-security/2006/08/25/0000.html
Many thanks to YAMAMOTO Takashi, Matt Thomas, and Christos Zoulas for help
stablizing kauth(9).
Full credit for the regression tests, making sure these changes didn't break
anything, goes to Matt Fleming and Jaime Fournier.
Happy birthday Randi! :)
- adapt to NVERIEXEC in init_sysctl.c.
- we now need "veriexec.h" for NVERIEXEC.
- "opt_verified_exec.h" -> "opt_veriexec.h", and include it only where
it is needed.
ps(1) to print incorrect information. Annotate the flags in the header files
to make sure that flags are not being re-used and move flags so that there
are no conflicts.
- use vmspace rather than proc or lwp where appropriate.
the latter is more natural to specify an address space.
(and less likely to be abused for random purposes.)
- fix a swdmover race.
rmind