to prevent deadlock on media unbind (which is called with
the interface wlock()'ed), the medias reader processes
that unbind was waiting for used to discard packets when
the interface could not be rlocked.
this has the unfortunate side effect that when we change
addresses on a interface that packets are getting lost.
this is problematic for the processing of ipv6 router
advertisements when multiple RA's are getting received
in quick succession.
this change removes that packet dropping behaviour and
instead changes the unbind process to avoid the deadlock
by wunlock()ing the interface temporarily while waiting
for the reader processes to finish. the interface media
is also changed to the mullmedium before unlocking (see
the comment).
avm fritzbox uses very long RA period so it effectively only
responds after a router solicitation. when there are multiple
fritzbox routers on the lan, then while configuring one prefix
of the first RA, the ip stack can drop the second router
advertisement and we would never get the second route.
packets can always get lost. so we just keep on sending router
solicitations (up to 3 times) to make sure we got all the RA's.
This patch makes 3 changes:
- It makes upas/fs send plumb messages when a message
changes in the background (eg, someone on another imap
connection opens a message and sets the read flag)
- It makes faces not complain when it gets one of these
new modify messages.
- It makes acme/Mail update the flags in the display
when it gets one of these messages.
on systems with serial console and graphics such as the raspberry pi,
it is nice to get a system shell on the serial console even when no
monitor is connected.
the console command runs a command or the system shell under
a new instance of kbdfs, optionally providing a serial console
when $console environment variable is set.
comparing m with MACHP() is wrong as m is a constant on 386.
add procflushothers(), which flushes all processes except up
using common procflushmmu() routine.
procflushmmu() returns once all *OTHER* processors that had
matching processes running on them flushed ther tlb/mmu state.
the caller of procflush...() takes care of flushing "up" by
calling flushmmu() later.
if the current process matched, then that means m->flushmmu
would be set, and hzclock() would call flushmmu() again.
to avoid this, we now check up->newtlb in addition to m->flushmmu
in hzclock() before calling flushmmu().
we also maintain information on which process on what processor
to wait for locally, which helps making progress when multiple
procflushmmu()'s are running concurrently.
in addition, this makes the wait condition for procflushmmu()
more sophisticated, by validating if the processor still runs
the selected process and only if it matchatches, considers
the MACHP(nm)->flushmmu flag.
The code had a nested use of the follow() function that could cause +=+
and -=- to register as ++ and --. The first follow() to execute could
consume a character and match and then the second follow() could consume
another character and match. For example i-=-10 would result in a syntax
error and i-=- would decrement i.
(imported from plan9port commit f1dd3f065a97f57bf59db2e3284868e181734159)
the change to support no-execute bits broke the original
raspberry pi1, as it uses backwards compatible page table
format.
to use the XN bit, subpage AP bits have to be disabled
using the XP bit in CP15 Control Register c1 Bit 23.
When plumbing an address like `3-`, Acme selects line 1,
and similarly `3+` selects line 5.
The same problem can be observed for character addresses (`#123+`)
but _not_ for ones like `+`, `.+` or `/foo/+`:
The problem only occurs when a number is followed by a direction (`-`/`+`).
Following along with the example `3-` through `address` (in addr.c):
We read `3` into `c` and match the `case` on line 239.
The `while` loop on line 242ff reads additional digits into `c`
and puts the first non-digit back by decrementing the index `q`.
Then we find the range for line 3 on line 251 and continue.
On the next iteration, we set `prevc` to the last `c`,
but since that part read ahead _into `c`_,
`c` is currently the _next_ character we will read, `-`,
and now `prevc` is too.
Then in the case block (line 210) the condition on line 211 holds
and Acme believes that it has read two `-` in sequence
and modifies the range to account for the “first” `-`.
The “second” `-` gets applied after the loop is done, on line 292.
So the general problem is:
While reading numbers, Acme reads the next character after the number into `c`.
It decrements the counter to ensure it will read it again on the next iteration,
but it still uses it to update `prevc`.
This change solves the problem by reading digits into `nc` instead.
This variable is used to similar effect in the block for directions (line 212)
and fills the role of “local `c` that we can safely use to read ahead” nicely.
(imported from plan9front a82a8b6368274d77d42f526e379b74e79c137e26)
To reproduce, create a column with at least two windows and resize
acme to have almost zero height.
(imported from plan9port commit 76b9347a5fa3a0970527c6ee1b97ef1c714f636b)
when a process does an exec syscall, procsetup() is called and
we have to disable the debug watchpoint registers. just clearing
p->dr is not enougth as we are not going thru a procsave() and
procrestore() cycle which would disable and reload the saved
debug registers.
instead of clearing debug registers in procfork(), we should
clear the saved debug registers before a process goes to die
(pexit() calls sched() with up->state = Moribund) as the Proc
structure can get reused for kernel processes (kproc) which
never call procfork() and would therefore have debug registers
loaded.
do incremental imap fetches after startup, fixes validity handling,
record flags correctly when we aren't in the process of directly
updating a message, fixes off by one in flag parsing, fixes
mis-indexing messages in sync when we get an unsolicited fetch
response.
for better system diagnostics, we *ALWAYS* want to record the parent
pid of a user process, regardless of if the child will post a wait
record on exit or not.
for that, we reverse the roles of Proc.parent and Proc.parentpid so
Proc.parentpid will always be set on rfork() and the Proc.parent
pointer will point to the parent's Proc structure or is set to nil
when no wait record should be posted on exit (RFNOWAIT flag).
this means that we can get the pid of the original parent process
from /proc, regardless of the the child having rforked with the
RFNOWAIT flag. this improves the output of pstree(1) somewhat if
the parent is still alive. note that theres no guarantee that the
parent pid is still valid.
the conditions are unchanged:
a user process that will post wait record has:
up->kp == 0 && up->parent != nil && up->parent->pid == up->parentpid
the boot process is:
up->kp == 0 && up->parent == nil && up->parentpid == 0
and kproc's have:
up->kp != 0 && up->parent == nil && up->parentpid == 0
this is a reimplementation of infernos os(1) command, which
allows running commands in the underhying host operating
system when inferno runs in hosted mode (emu). but unlike
inferno, we want to use it to run commands on the client
side of a inferno or drawterm session from the plan9 cpu
server, so it defaults to /mnt/term/cmd for the mountpoint.
Previously, reads of wctl files would return one byte less than
requested as the returned string must be null terminated. Now we pass
the actual size of the allocated buffer to the handler, which is large
enough to accommodate a trailing partial rune and terminating null
byte.
Ori_B reports that his controller gets stuck in the ahciencreset()
wait loop. so we implement a 1000 ms timeout. we replace delay()
with esleep() as we are always called from the ledkproc().
blink() could enter infinite delay loop as well, so instead of
waiting for the message to get transmitted we exit making it
non-blocking (we will get called again anyway).
the access to the controller map[] was wrong in ledkproc(). the
index is the controller number, not the drive number!
Support for 'path=', 'uname=', 'gname=', 'size=', and 'atime=' pax
headers is useful. Others are ignored, possibly with a warning.
We were running into missing support with the 'go' extraction.
At the same time, this cleans up the way that we handle paths,
getting rid of static buffers with hidden space at the front.
when making outgoing connections, the source ip was selected
by just iterating from the first to the last interface and
trying each local address until a route was found. the result
was kind of hard to predict as it depends on the interface
order.
this change replaces the algorithm with the route lookup algorithm
that we already have which takes more specific desination and
source prefixes into account. so the order of interfaces does
not matter anymore.
Tar specifies that a filename ending with '/' is a directory. We were
incorrectly looking at the short name. This meant that when we have long
filenames with a '/' at the 100th character, we would decide it was a
directory.
This change uses the long name when deciding the size for extraction,
and trusts the header size when just skipping forward in the stream.
extract1() expects two extra bytes to be avilabe before
fname buffer so it can prepend ./ before the name. this
used to be the case with name(), but was violated when
long name support was added and getname() was used in
place of name() which did not reserve the 2 extra bytes.
this change reserves two extra bytes in the getname()'s
static buffer and also removes the extra copy as name()
already makes a copy.
Since numeric timezone offsets are relative to GMT, initialise zone to
GMT so tm2sec(2) does not assume local time.
Note that if strtotm encounters a timezone *string* and consequently
overwrites zone then we will end up in the same mess since tm2sec(2)
only deals with GMT or local time.
there was a race between the sendproc putting the request on
the sreqrd[] id and the recvproc handling the response, and
potentially freeing the request before the sendproc() was
finished with the request (or the fid).
so we defer allocating a request id and putting it on the
sreqrd[] stage after we have completely generated the
request in vpack(). this prevents the handling of the request
before it is even sent.
this also means that the SReq should not be touched after
calling sendpkt(), submitreq(), submitsreq().
secondly, putsfid() needs to acquire the RWLock to make sure
sendproc() is finished with the request. the scenario is that
recvproc() can call respond() on the request before sendproc()
has unlocked the SFid.
move digest pointer into Mtree structrue and embed it into Idx struct
(which is embedded in Message) to avoid one level of indirection
during mtreecmp().
get rid of mtreeisdup(). instead we have mtreeadd() return the old
message in case of a collision. this avoids double lookup.
increase the hash table size for henter() and make it a prime.
on 386, the kernel memory region is mapped using huge 4MB pages
(when supported by the cpu). so the uncached pte manipulation
does not work to map the cursor data with uncached attribute.
instead, we allocate a memory page using newpage() and map
it globally using vmap(), which maps it uncached.
after issuing CR_RESETEP command, we have to invalidate
the endpoints output context buffer so that the halted/error
status reflects the new state. not doing so resulted in
the halted state to be stuck and we continued issuing
endpoint reset commands when we where already recovered.
handle the devusb Ep.clrhalt flag from devusb that userspace
uses to force a endpoint reset on the next transaction.
for servers that handle incoming network connections and authentication,
change the owner of the network connection file to the authenticated user
after successfull authentication.
note that we set the permissions as well to 0660 because old devip used
to unconditionally set the bits.
permission checking had the "other" and "owner" bits swapped plus incoming
connections where always owned by "network" instead of the owner of
the listening connection. also, ipwstat() was not effective as the uid
strings where not parsed.
this fixes the permission checks for data/ctl/err file and makes incoming
connections inherit the owner from the listening connection.
we also allow ipwstat() to change ownership to the commonuser() or anyone
if we are eve.
we might have to add additional restrictions for none at a later point...
we want devip to get reattached after hostowner has been written. factotum
already handles this with a private authdial() routine that mounts devip
when it is not present. so we detach devmnt before starting factotum,
and attach once factotum finishes.
the locking in proctext() is wrong. we have to acquire Proc.seglock
when reading segments from Proc.seg[] as segments do not
have a private freelist and can therefore be reused for other
data structures.
once we have Proc.seglock acquired, check that the process pid
is still valid so we wont accidentally read some other processes
segments. (for both proctext() and procctlmemio()). this also
should give better error message to distinguish the case when
the process did segdetach() the segment in question before we
could acquire Proc.seglock.
declare private functions as static.
there was a small window between modifying mmutop and switching the
asid where the core could bring in the new entries under the old asid
into the tlb due to speculation / prefetching.
this change moves the entering of the page tables into mmutop after
setttbr() to prevent this scenario.
due to us switching to the resereved asid 0 on procsave()->putasid(),
the only asid that could have potentially been poisoned would be asid 0
which does not have any user mappings. so this did not show any noticable
effect.
when a process state has not been saved (Proc.mach != nil)
then the contents of Proc.sched should be considered invalid.
to approximate a stacktrace in this case, we use the error
stack and get a stacktrace from the last waserror() call.
pexit() and pprint() can get called outside of a syscall
(from procctl()) with a process that is in active note
handling and require floating point in the kernel on amd64
for aesni (devtls).