NetBSD's shutdown behavior of more than 6 years before rev 1.176.
Ok joerg@.
It is essential that we restore some hardware to initial conditions
before rebooting, in order to avoid interfering with the BIOS
bootstrap. For example, if NetBSD gives control back to the Soekris
comBIOS while the kernel text is write-protected, the BIOS bootstrap
hangs during the power-on self-test, "POST: 0123456789bcefghip".
In principle, bus masters can also interfere with BIOS boot.
DragonflyBSD uses the crit names for something quite different.
- Add a kpreempt_disabled function for diagnostic assertions.
- Add inline versions of kpreempt_enable/kpreempt_disable for primitives.
- Make some more changes for preemption safety to the x86 pmap.
can register a shutdown handler explicitely.
Install a pci bus shutdown handler which disables bus master accesses
for all childs, so the drivers don't need to care.
This will hopefully be sufficient to replace the shutdownhooks
(together with the powerhooks). (It has been suggested to use some
general event notification framework for shutdown handlers, but there
might be cases where shutdown handlers must be run in an order following
the device hierarchy, which wouldn't be easy with event handlers
not tied to drivers.)
approved by David Young
too much in the RB_HALT case, making the "press a key to reboot" prompt
a bad joke. doshutdownhooks() should do shutdownhooks, not more.
Since it is md code which decides about halt/poweroff etc,
pmf_system_shutdown() should be called from there if appropriate.
Instead of passing the (un)real system call code and syscall table pointer,
just pass the number of arguments - which is what ktrace really wants.
Ride forthcoming 4.99.53
It will get __UNCONST() applied in the systrace code if/when systrace tries
to change the arguments. This sucks since the syscall args might be in
the trap frame, and the syscall might return ERESTART so the restarted call
would use the wrong arguments.
OTOH systrace() (as a security measure) is almost impossible to implement
for a threaded app (validated filenames can be changed before namei() reads
them into memory).
The current code is just plain broken for threaded apps - data that needs
to be lwp-specified is proc-specific.
I believe ad is planning to nuke systrace ...
The general trend is to remove it from all kernel interfaces and
this is a start. In case the calling lwp is desired, curlwp should
be used.
quick consensus on tech-kern
- uiomove: don't bother dropping kernel_lock if moving less than 1k.
- Catch up with vfsops reference counting changes (for LKMs).
- Add crit_enter()/crit_exit(). These bound critical sections in which
kernel preemption is to be disabled. Better names welcome.
config_handle_wedges() and read_disk_sectors(). On x86, handle_wedges()
is a thin wrapper for config_handle_wedges(). Share opendisk()
across architectures.
Add kernel code in support of specifying a root partition by wedge
name. E.g., root specifications "wedge:wd0a", "wedge:David's Root
Volume" are possible. (Patches for config(1) coming soon.)
In support of moving disks between architectures (esp. i386 <->
evbmips), I've written a routine convertdisklabel() that ensures
that the raw partition is at RAW_DISK by following these steps:
0 If we have read a disklabel that has a RAW_PART with
p_offset == 0 and p_size != 0, then use that raw partition.
1 If we have read a disklabel that has both partitions 'c'
and 'd', and RAW_PART has p_offset != 0 or p_size == 0,
but the other partition is suitable for a raw partition
(p_offset == 0, p_size != 0), then swap the two partitions
and use the new raw partition.
2 If the architecture's raw partition is 'd', and if there
is no partition 'd', but there is a partition 'c' that
is suitable for a raw partition, then copy partition 'c'
to partition 'd'.
3 Determine the drive's last sector, using either the
d_secperunit the drive reported, or by guessing (0x1fffffff).
If we cannot read the drive's last sector, then fail.
4 If we have read a disklabel that has no partition slot
RAW_PART, then create a partition RAW_PART. Make it span
the whole drive.
5 If there are fewer than MAXPARTITIONS partitions,
then "slide" the unsuitable raw partition RAW_PART, and
subsequent partitions, into partition slots RAW_PART+1
and subsequent slots. Create a raw partition at RAW_PART.
Make it span the whole drive.
The convertdisklabel() procedure can probably stand to be simplified,
but it ought to deal with all but an extraordinarily broken disklabel,
now.
i386: compiled and tested, sparc64: compiled, evbmips: compiled.
with newlock2 merge:
Replace the Mach-derived boolean_t type with the C99 bool type. A
future commit will replace use of TRUE and FALSE with true and false.
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.
