if we hold a spin mutex, since we can trivially get into deadlocks if we
start switching out of processes that hold spinlocks. Checking to see if
interrupts were disabled was a sort of cheap way of doing this since most
of the time interrupts were only disabled when holding a spin lock. At
least on the i386. To fix this properly, use a per-process counter
p_spinlocks that counts the number of spin locks currently held, and
instead of checking to see if interrupts are disabled in the witness code,
check to see if we hold any spin locks. Since child processes always
start up with the sched lock magically held in fork_exit(), we initialize
p_spinlocks to 1 for child processes. Note that proc0 doesn't go through
fork_exit(), so it starts with no spin locks held.
Consulting from: cp
- Don't try to grab Giant before postsig() in userret() as it is no longer
needed.
- Don't grab Giant before psignal() in ast() but get the proc lock instead.
supported architectures such as the alpha. This allows us to save
on kernel virtual address space, TLB entries, and (on the ia64) VHPT
entries. pmap_map() now modifies the passed in virtual address on
architectures that do not support direct-mapped segments to point to
the next available virtual address. It also returns the actual
address that the request was mapped to.
- On the IA64 don't use a special zone of PV entries needed for early
calls to pmap_kenter() during pmap_init(). This gets us in trouble
because we end up trying to use the zone allocator before it is
initialized. Instead, with the pmap_map() change, the number of needed
PV entries is small enough that we can get by with a static pool that is
used until pmap_init() is complete.
Submitted by: dfr
Debugging help: peter
Tested by: me
bolted to a ne-2000 chip. This is necessary for the NetGear FA-410TX
and other cards.
This also requires you add mii to your kernel if you have an ed driver
configured.
This code will result in a couple of timeout messages for ed on the
impacted cards. Additional work will be needed, but this does work
right now, and many people need these cards.
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
with egcs-1.1.1. bus_space_write_multi_2() had an extra operation that
should have been removed.
Remove it.
This fixes the panic when bus_space_write_multi_2() is used.
Obtained from: jake
a regular basis. Adjust our linux emulation to conform. This will
cause more dirty pages to be left for the pagedaemon to deal with,
but our new low-memory handling code can deal with it. The linux
way appears to be a trend, and we may very well make MAP_NOSYNC the
default for FreeBSD as well (once we have reasonable sequential
write-behind heuristics for random faults).
(will be MFC'd prior to 4.3 freeze)
Suggested by: Andrew Gallatin
rather than in silly places like "VFS Cluster debugging". People
should really be using COMPAT_LINUX instead of the linux module on
dynamic systems like -current.
gcc -aout -mno-underscores. The bioscall.s tweak is not an a.out
requirement really, but to work around the bugs in the antique version of
gas that used for a.out. Makefile hacks are all that is needed to
get an a.out kernel. There is no telling if it will work though.
This is little more than an academic curiosity anyway since all it is
good for is situations where the boot code is hard wired, eg: rom
bootstraps (such as the gnat box).
GENERIC:
...
size -aout kernel ; chmod 755 kernel
text data bss dec hex
3051520 368640 198688 3618848 373820
and used in C or vice versa. The elf compiler uses the same names
for both. Remove asnames.h with great prejudice; it has served its
purpose.
Note that this does not affect the ability to generate an aout kernel
due to gcc's -mno-underscores option.
moral support from: peter, jhb
to be more like Xint0x80_syscall and less like c function syscall().
- Reduce code duplication between the int0x80 and lcall handlers by
shuffling the elfags into the right place, saving the sizeof the
instruction in tf_err and jumping into the common int0x80 code.
Reviewed by: peter
depend on this. The linux ABI emulator tries to use it for some linux
binaries too. VM86 had a bigger cost than this and it was made default
a while ago.
Reviewed by: jhb, imp
the the original trapframe of the syscall, trap, or interrupt that entered
the kernel. Before SMPng, ast's were handled via a psuedo trap at the
end of doerti. With the SMPng commit, ast's were broken out into a
separate ast() function that was called from doreti to match the behavior
of other architectures. Unfortunately, when this was done, the
p_md.md_regs member of curproc was not updateda in ast(), thus when
signals are handled by userret() after an interrupt that returns to
userland, we end up using a stale trapframe that will result in the
registers from the old trapframe overwriting the real trapframe and
smashing all the registers right before we return to usermode. The saved
%cs:%eip from where we were in usermode are saved in the trapframe for
example.
- Don't use an atomic operation to update cnt.v_soft in ast(). This is
the only place the variable is written to, and sched_lock is always
held when it is written, so it is already protected and the mutex release
of sched_lock asserts a memory barrier that ensures the value will be
updated in a timely fashion.
- Don't hold sched_lock around addupc_task() as this apparently breaks
profiling badly due to sched_lock being held across copyin().
Reported by: bde (2)
scheduling an interrupt thread to run when needed. This has the side
effect of enabling support for entropy gathering from interrupts on
all architectures.
- Change the software interrupt and x86 and alpha hardware interrupt code
to use ithread_schedule() for most of their processing when scheduling
an interrupt to run.
- Remove the pesky Warning message about interrupt threads having entropy
enabled. I'm not sure why I put that in there in the first place.
- Add more error checking for parameters and change some cases that
returned EINVAL to panic on failure instead via KASSERT().
- Instead of doing a documented evil hack of setting the P_NOLOAD flag
on every interrupt thread whose pri was SWI_CLOCK, set the flag
explicity for clk_ithd's proc during start_softintr().
in mi_switch() just before calling cpu_switch() so that the first switch
after a resched request will satisfy the request.
- While I'm at it, move a few things into mi_switch() and out of
cpu_switch(), specifically set the p_oncpu and p_lastcpu members of
proc in mi_switch(), and handle the sched_lock state change across a
context switch in mi_switch().
- Since cpu_switch() no longer handles the sched_lock state change, we
have to setup an initial state for sched_lock in fork_exit() before we
release it.
always on curproc. This is needed to implement signal delivery properly
(see a future log message for kern_sig.c).
Debogotified the definition of aston(). aston() was defined in terms
of signotify() (perhaps because only the latter already operated on
a specified process), but aston() is the primitive.
Similar changes are needed in the ia64 versions of cpu.h and trap.c.
I didn't make them because the ia64 is missing the prerequisite changes
to make astpending and need_resched per-process and those changes are
too large to make without testing.
tsc_present in the right places (together with other variables of the
same linkage), and don't use messy ifdefs just to avoid exporting it in
some cases.
