sigreturn() sometimes failed for ordinary returns from signal handlers.
Failures of ordinary returns "can't happen" and are badly handled.
"Temporary" fix: allow users to corrupt PSL_RF. This is fairly
harmless. A correct fix would involve saving the old %eflags (and
perhaps the old segment registers) where the user can't get at them.
WDTR, and message reject handlers so they don't need to exist in the
sequencer. All three of these cases are not on the critical path, so it
makes little sense to use up precious sequencer ram for them.
properly from the beginning:
1) The `kern_devconf' struct should be a part of the driver's
`softc' structure (now it is).
2) The `description' should say what the device actually is,
rather than just giving a model number (now it does).
3) The device should be registered even if the probe fails, so
that it can be reconfigured later.
4) For netifs, the device state should follow the IFF_UP flag.
Other network interfaces should follow this example. (Please?) Eventually
there should be a rundown routine doing the equivalent of setting IFF_UP
off, and perhaps more if warranted.
attempted to check for insecure and fatal eflags and segment
selectors, but missed many cases and got the IOPL check back to
front. The other syscalls didn't check at all.
sys_process.c, machdep.c:
Only allow PT_WRITE_U to write to the registers (ordinary and FP).
psl.h, locore.s, machdep.c:
Eliminate PSL_MBZ, PSL_MBO and PSL_USERCLR. We are not supposed
to assume anything about the reserved bits. Use PSL_USERCHANGE
and PSL_KERNEL instead. Rename PSL_USERSET to PSL_USER.
exception.s:
Define a private label for use by doreti when returning to user
mode fails.
machdep.c:
In syscalls, allow changing only the eflags that can be changed on
486's in user mode (no longer attempt to allow benign IOPL changes;
allow changing the nasty PSL_NT; don't allow changing the i586
bits).
Don't attempt to check all the cases involving invalid selectors
and %eip's. Just check for privilege violations and let the invalid
things cause a trap.
procfs_machdep.c:
Call the ptrace register functions to do all the work for reading
and writing ordinary registers and for single stepping.
trap.c:
Ignore traps caused by PSL_NT being set. Previously, users could
cause a fatal trap in user mode by setting PSL_NT and executing an
iret, and a fatal trap in kernel mode by setting PSL_NT and making
a syscall. PSL_NT was cleared too late and not in enough modes to
fix the problem.
Make all traps in user mode (except T_NMI) nonfatal.
Recover from traps caused by attempting to load invalid user
registers in doreti by restarting the traps so that they appear to
occur in user mode.
---
Fix bogons that I noticed while fixing the above:
psl.h:
Fix some comments.
Uniformize idempotency ifdef.
exception.s, machdep.c:
Remove rsvd[0-14]. rsvd0 hasn't been reserved since the 486 came
out. Replace rsvd0 by `align'. rsvd[0-11] used wrong (magic
non-unique) trap numbers. Replace rsvd[1-14] by rsvd.
locore.s:
Enable alignment check flag on 486's and 586's.
machdep.c:
Use a better type for kstack[].
Use TFREGP() to find the registers.
Reformat ptrace functions from SEF to something closer to KNF.
procfs_machdep.c:
The wrong pointer to the registers got fixed as a side effect.
Implement reading and writing of FP registers.
/proc/*/*regs now work (only) for processes that are in memory.
Clean up comments.
trap.c, trap.h:
Remove unused trap types.
unreachable case label in kdb_trap().
Use the correct case labels in kdb_trap() so that normal ddb entry doesn't
print a message.
Change all printf's to db_printf's. Now you can put a breakpoint at printf,
and ddb entry messages don't spam the syslog output.
Cosmetic:
Use ISPL() instead of magic numbers.
Don't compile the unused function kdb_kbd_trap().
Improve some asms.
Print the arg to Debugger().
protected drive at open() time has been *totally bogus*! The guy who
submitted it didn't understand all the implications of calling
set_motor(), and the `who' who included the patch into the tree did it
blindly... Pleeeeze, don't commit code to this driver unless you are
really going to understand what it does! This one caused me to pull
out even more hears, and those who know me do know that i ain't got
too many o'them. :-)
No kernel config options anymore besides keyboard language layout.
Virtual consoles are now dynamically allocated, no NCONS anymore.
Software cursor blinking/nonblinking.
Visual bell for laptops (don't beep at meetings :-).
Cursor/bell default type setable via config "flags" instead of as defines.
Cursor/bell type setable via ioctl's.
New video modes 80x30 80x60 for some laptops, and those with multisync monitors.
Scroll-lock history (length currently fixed at 100 lines).
Lots of cleanups, some only commented out for now (will goaway soon).
Support for new features in vidcontrol/kbdcontrol.
Updated manpages.
now marked busy as long as it's being in non-reset state, and the
drives are busy as long as at least one instance is open.
Also reformat everything to fit into 80 columns again.
Changed my mind wrt. error reporting for a write-protected drive and
an open() with write intent; ENXIO has been too weird, now return EIO.
Some portions of the code need to be rewritten to use tprintf()
instead of simple printf()'s, so the messages will also appear on the
session terminal, however.
Wangtek PC-02 QIC-02 controller with Cipher 150MB tape drive
Any attemp to open /dev/rwt0 hangs.
The following patch to /sys/i386/isa/wt.c is derived from Mikael
Hybsch's wt driver.
Submitted by: Terry Lee <terry@uivlsi.csl.uiuc.edu>
much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.
The majority of the merged VM/cache work is by John Dyson.
The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.
vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme. The scheme is almost fully compatible with the old filesystem
interface. Significant improvement in the number of opportunities for write
clustering.
vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff.
vm_object.c:
Yet more improvements in the collapse code. Elimination of some windows that
can cause list corruption.
vm_pageout.c:
Fixed it, it really works better now. Somehow in 2.0, some "enhancements"
broke the code. This code has been reworked from the ground-up.
vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.
pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.
vm_glue.c
Much simpler and more effective swapping code. No more gratuitous swapping.
proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.
swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the
code doesn't need it anymore.
machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.
machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.
ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on
busy buffers.
Submitted by: John Dyson and David Greenman
shifting. Also correct the original code as Garrett noticed it in mail.
Leave the mishandled code in to use it later if future versions of gcc
are correct. The code was part of the calibrate_cyclecounter routine to
get the speed of the pentium chip.
floppy driver (or in the hardware?). It turned out to be caused by
spurious interrupts, right after an FDC reset.
Also major cleanup in the low-level structure, there are now functions
performing error-checks for the FDC I/O.
Submitted by: (mostly) Peter Dufault <dufault@FreeBSD.org>
no more DOS boots to start it up.
Simply did a localized nuke of the OUTB macro in this file. This is
a kludge, since it seems it may actually be necessary in other GUS
files (tbd).
Thanks to: Amancio Hasty & Ken Hornstein
correct console number for the VT_WAITACTIVE ioctl. Invalid console numbers
caused waiting on an invalid pointer.
Use bcopyw() instead of move_up() and move_down(). bcopyw() handles
overlapped copies and should be faster. Actually use bcopy(). bcopy()
is slightly faster if video memory is 16-bit and about twice as fast if
it is 32-bit. bcopy() is said to fail on someGA's, but syscons already
depends on it working for other accesses to video memory.
Remove bogus input operands for fnsave(), fnstcw() and fnstsw().
Change all fwait's to fnop's. This might help avoid hardware bugs.
Wait after fninit with an fnop. This should be safer now.
Fix some spelling and formatting errors.
Use natural sizes for control and status words (u_short, promotes to int).
Don't clobber the SWI_CLOCK_MASK bits in npx0_imask when using IRQ13.
Set the devconf state correctly (always busy, if configured). Improve
code for npx_registerdev() a little (gcc can't keep id->id_unit in a
register for some reason). Don't register a nonexistent npx device.
Print a useful message in npxattach() again (delete references to errors
and not the whole message). Don't print "387 emulator" if there is no
emulator in the kernel.
Use %p for pointers in error messages.
Don't clobber the FPU state when there is an FPU exception. Just clear
the exception flags (after saving the flags as before). This allows
debuggers and SIGFPE handlers to look at the full exception state.
SIGFPE handlers should normally return via longjmp(), which restores a
good FPU state (as before). Returning from a SIGFPE handler may leave
the FPU in the wrong state (as before).
Clear the busy latch _after_ clearing the exception flags so that there
is less chance of getting a bogus h/w interrupt for a control operation.
Clear the saved exception status word when the next FPU instruction is
excuted so that it doesn't stick around until the next exception.
Clear the busy latch after fnsave() in npxsave() in case it was set when
npxsave() was called.
