routines. Otherwise we run into trouble with speculative tlb preloads
on SMP systems. This effectively defeats Jeff's revision 1.438
optimization (for his pentium4-M laptop) in the SMP case. It breaks
other systems, particularly athlon-MP's.
the ACPI timer and we shouldn't do that if ACPI is already around to do
that for us.
- Set a description and tweak the order of checks in the probe function
to more closely match other PCI drivers.
This should probably be moved to sys/dev/piix/piix.c at some point and
turned on for all i386 kernels rather than just SMP ones.
enable strict checks of the AML. Our default behavior will be to relax
checks to work on as many platforms as possible. Also clean up and document
other ACPI options while I'm here.
Xcpustop(). %es is used in at least the call to savectx() when savectx()
calls bcopy(), so not loading it was fatal if a stop IPI interrupts
user mode.
This reduces bugs starting and stopping CPUs for debuggers. CPUs are
stopped mainly in kdb_trap() and cpu_reset(). At reset time there is
a good chance that all the CPUs are in the kernel, so the bug was
probably harmless then.
I changed. That is never a good sign.
1) only map 1 page at address zero, not 4096 pages
2) page 1 starts at address 4096 (PAGE_SIZE) not 4095 (PAGE_MASK). I
don't even want to think what the pte's looked like.
3) subtract the r/o page group start address from the end before
converting it to a count. Otherwise an extra page is mapped.
If you were affected by this, the symptoms of this was a hang at boot
after the spinner. Sorry folks. :-(
"You broke my laptop!" by: sam
use because a kernel thread is borrowing it. The borrowed page table
can change spontaneously, making any dependence on its continued use
subject to a race condition.
- _pmap_unwire_pte_hold() cannot use pmap_is_current(): If a change is
made to a page table page mapping for a borrowed page table, the TLB
must be updated.
In collaboration with: tegge
- Return NULL instead of returning memory outside of the stackgap
in stackgap_alloc() (FreeBSD-SA-00:42.linux)
- Check for stackgap_alloc() returning NULL in ibcs2_emul_find();
other calls to stackgap_alloc() have not been changed since they
are small fixed-size allocations.
- Replace use of strcpy() with strlcpy() in exec_coff_imgact()
to avoid buffer overflow
- Use strlcat() instead of strcat() to avoid a one byte buffer
overflow in ibcs2_setipdomainname()
- Use copyinstr() instead of copyin() in ibcs2_setipdomainname()
to ensure that the string is null-terminated
- Avoid integer overflow in ibcs2_setgroups() and ibcs2_setgroups()
by checking that gidsetsize argument is non-negative and
no larger than NGROUPS_MAX.
- Range-check signal numbers in ibcs2_wait(), ibcs2_sigaction(),
ibcs2_sigsys() and ibcs2_kill() to avoid accessing array past
the end (or before the start)
work in, but we had it mapped read-only. While this has always been the
case, the PG_PS enable hack hid it and the apm bios code ended up taking
advantage of it.
I do not yet understand why, but apm *depended* on the fact that the old
PSE code caused the first 1MB of ram to be mapped read/write because it
was in the same 4MB page as the kernel text+data+bss blob.
If anybody ever tried DISABLE_PSE before, apm would not work.
If your cpu did not have PSE, apm would not work there either (eg: 486).
This bug has been around for a Very Long Time.
The Pentium-4-fix commits did not emulate this unintended side effect of
the PSE post-early-boot fixup, and thus apm blew up. I've added a hack to
emulate the bug until either apm is fixed or we set fire to our bridges.
This is bad though because it gives kernel mode code the opportunity
to accidently write to the first few megs of the general page pool
which is remapped at KERNBASE. It needs to be fixed properly.
A small helper function pmap_is_prefaultable() is added. This function
encapsulate the few lines of pmap_prefault() that actually vary from
machine to machine. Note: pmap_is_prefaultable() and pmap_mincore() have
much in common. Going forward, it's worth considering their merger.
avoid problems with some Pentium 4 cpus and some older PPro/Pentium2
cpus. There are several problems, some documented in Intel errata.
This patch:
1) moves the kernel to the second page in the PSE case. There is an
errata that says that you Must Not point a 4MB page at physical
address zero on older cpus. We avoided bugs here due to sheer luck.
2) sets up PSE page tables right from the start in locore, rather than
trying to switch from 4K to 4M (or 2M) pages part way through the boot
sequence at the same time that we're messing with PG_G.
For some reason, the pmap work over the last 18 months seems to tickle
the problems, and the PAE infrastructure changes disturb the cpu
bugs even more.
A couple of people have reported a problem with APM bios calls during
boot. I'll work with people to get this resolved.
Obtained from: bmilekic
prior to invalidating the TLB to be certain that the processor doesn't
keep a cached copy.
Discussed with: pete
Paniced: tegge
Pointy Hat: The usual spot
the TLB and ~1600 if it is not. Therefore, it is more effecient to
invalidate the TLB after operations that use CMAP rather than before.
- So that the tlb is invalidated prior to switching off of a processor, we
must change the switchin functions to switchout functions.
- Remove td_switchout from the thread and move it to the x86 pcb.
- Move the code that calls switchout into swtch.s. These changes make this
optimization truely x86 specific.
This is just a cleanup here (modulo rev.1.108 of kern/tty.c), since the
input speed can be different from to output speed and extra code to
handle both speeds naturally handled all cases.
provide no methods does not make any sense, and is not used by any
driver.
It is a pretty hard to come up with even a theoretical concept of
a device driver which would always fail open and close with ENODEV.
Change the defaults to be nullopen() and nullclose() which simply
does nothing.
Remove explicit initializations to these from the drivers which
already used them.
cd_setreg() were still using !(read_eflags() & PSL_I) as the condition
for the lock hidden by COM_LOCK() (if any) being held. This worked
when spin mutexes and/or critical_enter() used hard interrupt disablement,
but it has caused recursion on the non-recursive mutex com_mtx since
all relevant interrupt disablement became soft. The recursion is
harmless unless there are other bugs, but it breaks an invariant so
it is fatal if spinlocks are witnessed.
