wtop() checked w->topped == topped as a fast exit. if you
had the top most window not being current (== input) which
can happen when you delete the current window, then wtop would
after resize would not make the window current because it
is already top topmost one. wtopme() and wcurrent() both are
non-ops when window is already the topmost or window is already
current, so remove the check as its not needed. also topping
the window feels less sluggish.
sort the window array by w->topped before reshaping all
windows. this preserves the window z-order.
remove implicit focus change on reshape/move. it called
wcurrent() in wtcl thread which might send a wctl message
to itself, bad... also we might not want to change focus
on reshape, like for the rio resize. so we set the input
window explicitely in all call sites.
window deletion was racy. wclosewin() destroys w->i, but
it is called outside the wctl thread so it might just
free the image under libframe doing some text selection.
this is fixed the following: add wclunk() function,
which basically just marks the window as deleted and
removes the reference from the window[] and hidden[]
arrays. (called on wclose() when refcount drops to
zero). wclosewin() now just frees the image and is only
called from the wctl thread on exit or when handing
the Deleted message.
get a reference to the window when doing sweeping or
moving as the filesystem might just clunk it under
us and we might end up sending wctl messages to
a Exited window.
wctl resize message has to fail if the window is not
current as it might be hidden... would also be annoying.
this is to catch crazy color channels like k8a8 and the 15/16 bit
ones and CMAP. basically, just convert to RGBA32 or RGB24 depending
on if it has an alpha channel.
as the menu is displayed, the window might go away or change its
label causing menuhit() to dereference bad memory. just strdup()
the labels before passing to menu3str to prevent accidents.
avoid double entries in the cache for copen() and properly handle
locking so we wont just give up if we cant lock the Mntcache entry,
but drop the cache lock, qlock the Mntcache entry, and then recheck
the cache.
general cleanup (cdev -> ccache, use eqchantdqid())
the lock order of page.Lock -> palloc.hashlock was
violated in cachedel() which is called from the
pager. change the code to do it in the right oder
to prevent deadlock.
change lookpage to retry on false hit. i assume that
a false hit means:
a) we'r low on memory -> cached page got uncached/reused
b) duppage() got called on the page, meaning theres another
cached copy in the image now.
paging in is expensive compared to the hashtable lookup, so
i think retrying is better.
cleanup fixfault, adding comments.
swaped pages use a 8bit refcount where as the Page uses a 16bit one.
this might be exploited with having a process having a single page
swaped out and then forking 255 times to make the swap map refcount
overflow and panic the kernel.
this condition is probably very rare. so instead of doubling the
size of the swap map, we add a single 32bit refcount swapalloc.xref
which will keep the combined refcount of all swap map entries who
exceeded 255 references.
zero swapimage.c in setswapchan() after closing it as the stat() call
below might error leaving a dangeling pointer.
attachimage()'s approach to handling newseg() error is flawed:
a) the the image is on the hash table, but ref is still 0, and
there is no segment/pages attached to it so nobody is going to
reclaim / putimage() it -> leak
b) calling pexit() would deadlock us because exec has acquired
up->seglock when calling attachimage(), so this would just deadlock.
the fix does the following:
attachimage() will putimage() and nexterror() if newseg() fails
instead of pexit(). this is less surprising.
exec now keeps the condition variable commit which is set once
we are commited / reached the point of no return and check this
variable in the highest waserror() handler and pexit() us there.
this way we have released up all the locks and pexit() will
cleanup.
note: this bug shouldnt us hit in with the current newseg()
implementation as it uses smalloc() which would wait to
satisfy the allocation instead of erroring.
kstrcpy() did not null terminate for < 4 byte buffers. fixed,
but i dont think there is any case where this can happen in
practice.
always set malloctag in kstrdup(), cleanup.
always use ERRMAX bounded kstrcpy() to set up->errstr, q->err
and note[]->msg. paranoia.
instead of silently truncating interface name in netifinit(),
panic the kernel if interface name is too long as this case
is clearly a mistake.
panic kernel when filename is too long for addbootfile() in
devroot. this might happen if your kernel configuration is
messed up.
When running "?c -p ...", ensure the backend cpp recognizes C++ comments.
2c(1) states that the compilers recognize // comments, and the bare compilers
do. But if you invoke the compiler with '-p', the backend cpp process
doesn't handle // comments properly unless you also give ?c the undocumented
'-+' option (which it passes through to cpp).
in devproc status read handler the p->status, p->text and p->user
could overflow the local statbuf buffer as they where copied into
it with code like: memmove(statbuf+someoff, p->text, strlen(p->text)).
now using readstr() which will truncate if the string is too long.
make strncpy() usage consistent, make sure results are always null
terminated.
use fastclock timer (pit2) to measure cpufreq in guesscpuhz(). this
gives a bigger period minimizing the danger of overrun as pit2 runs
at the constant maximum period of 0x10000 ticks. also use smaller
loop increments (1000) and bigger maximum loop upper bound.
move the loops < ... check to the bottom of the loop so we get the
effective count *before* adding the next loop increment.
ilock() while doing measurements in guesscpuhz() to prevent accidents
with other processors reading fastclock or doing guesscpuhz()
in parralel.
export new i8253reset() function for apm to reset the timers after
a apm bios suspend.
we have to acquire p->seglock before we lock the individual
segments of the process and lock them. if we dont then pexit()
might free the segments before we can lock them causing the
"qunlock called with qlock not held, from ..." prints.
* disallow snarf on password entries
* remove current title label as it is displayed in the page list (redundant)
* avoid redrawing page list just to update the title
* check if the chan changed for backup bitmap in pl_rtdraw()
send ACK reply for duplicate data packets in case our ack response
got lost. make sure packets are in sequence and ignore out of
oder packets (except the ones we'v already acked).
