some (hopefully) less offensive stupidity:
If we detect that a user has loaded a module that fails to initialize
itself correctly, panic. There really isn't a safe way to recover from
something like this; we can't know that the module is bad until after
the entry point is called, by which time it's too late to do anything
about it.
- Add $Id$ string.
- Fix comment ("we might *not* be able to unload the
module afterwards without panicking...")
- Get rid of variable 'j' that I used in name checking
for(;;) loop and use 'i' instead (I thought there'd be
a problem with this, but there isn't).
if_tun_mod, etc...) from crashing the system. These modules are useful,
but because they don't yet have proper load()/unload() functions,
they can lead to panics: if, for example, you load the if_ppp module,
any user can panic the system by running modstat.
You can also hang the system outright if you try to unload the PPP
module too.
Changes are as follows:
- Save the name passed to us during the RESERVE stage for name matching
(we can't load if_ppp_mod twice: we've have two ppp0's and two ppp1's,
which is beyond strange). This makes the lkmexists() cheks somewhat
redundant, but there's no way around it that I can see.
- If we call the module entry point and find that we have no lkm_any
structure in our 'private' section, create a fake one. This keeps
modstat happy. We mark such modules as LM_UNKNOWN.
- Don't allow LM_UNLOAD modules to be unloaded: it just ain't
possible. (Unless someone wants to write a pppunattach() function. :( )
- In lkmunreserve(), mark private.lkm_any as NULL so we don't get
confused later. I think this is bogus, but I can't prove it.
XXX: the name matching used to keep the user from loading two
instances of the same module can easily be defeated simply by
changing the module name or, in the case of the oddball modules,
simply by renaming the module files. I haven't found a nice simple
way to tell one module from another.
is necessary in order for panic+sync to work. Will also gloss over a panic
that Jordan was having with the install floppies that remains unexplainable.
2) Handle "bogus_page" a little better.
3) Set page protection to VM_PROT_NONE if the entire page has become !valid.
Submitted by: John Dyson (2&3), me (1).
through a temporary buffer instead of one character at a time. The old
method takes about 6 usec/char on a 486DX2/66. This is larger than than
the combined interrupt and PIO overhead for a 16550!
This change was first implemented in 1.1.5. It was rewritten for 2.1.
The clist access functions allow a simpler implementation at some cost
in correctness and speed. There needs to be an ungetc() function to
recover from EFAULT, and it wastes time to copy through a temporary
buffer.
Don't snoop on single characters that weren't read due to EFAULT.
Rewrite a snoop comment in my approximation to English.
Undo bogus exportation of ttnread().
Fixed remaining known bugs in the buffer IO and VM system.
vfs_bio.c:
Fixed some race conditions and locking bugs. Improved performance
by removing some (now) unnecessary code and fixing some broken
logic.
Fixed process accounting of # of FS outputs.
Properly handle NFS interrupts (B_EINTR).
(various)
Replaced calls to clrbuf() with calls to an optimized routine
call vfs_bio_clrbuf().
(various FS sync)
Sync out modified vnode_pager backed pages.
ffs_vnops.c:
Do two passes: Sync out file data first, then indirect blocks.
vm_fault.c:
Fixed deadly embrace caused by acquiring locks in the wrong order.
vnode_pager.c:
Changed to use buffer I/O system for writing out modified pages. This
should fix the problem with the modification date previous not getting
updated. Also dramatically simplifies the code. Note that this is
going to change in the future and be implemented via VOP_PUTPAGES().
vm_object.c:
Fixed a pile of bugs related to cleaning (vnode) objects. The performance
of vm_object_page_clean() is terrible when dealing with huge objects,
but this will change when we implement a binary tree to keep the object
pages sorted.
vm_pageout.c:
Fixed broken clustering of pageouts. Fixed race conditions and other
lockup style bugs in the scanning of pages. Improved performance.
drivers to protect DDB from being invoked while the console is in
process-controlled (i.e., graphics) mode.
Implement the logic to use this hook from within pcvt. (I'm sure
Søren will do the syscons part RSN).
I've still got one occasion where the system stalled, but my attempts
to trigger the situation artificially resulted int the expected
behaviour. It's hard to track bugs without the console and DDB
available. :-/
Added a new type to uiomove - "UIO_NOCOPY" which causes it to update
pointers and counts, but doesn't do any data copying. This is needed
for upcoming changes to the way that the vnode pager does its page
outs.
Added a new hash init function call "phashinit" that allocates and
initializes a prime number sized hash table.
vfs_cache.c:
Changed hashing algorithm to use the remainder of dividing by a prime
number to improve the distribution characteristcs. Uses new phashinit
function in kern_subr.c.
#179). The fix implements a ttyhalfclose() (sort of), resetting the
session and pgrp pointers when the physical device is about to be
closed.
Suggested by: bde
1) Preserve old buffer contents when input buffer overflows.
Old code clear buffer and rewrite it again, if !MAXBEL
(for MAXBEL it does right thing :-).
F.e. if you type too long string, last chars passed,
not first ones as expected.
Moreover, it flush output queue too in this case without any needs.
2) Don't do IXOFF, if IGNCR and c==\r, ignore completely.
3) If PARMRK is active and !ISTRIP and char == 0377
put yet one 0377 to distinguish it from parity mark sequence.
POSIX standard (thanx Bruce).
Reviewed by:
Submitted by:
Obtained from:
CVS:
merged cache changes, and figure it out based on the B_VMIO buffer flag.
Fixes a problem where delayed write VMIO buffers would sometimes get
recopied into kernel-alloced memory.
Submitted by: John Dyson
Andrey A. Chernov
Bruce Evans
Poul-Henning Kamp
Bill Paul
David Greenman
Garrett Wollman
Joerg Wunsch