How This Guy Builds Mesmerizing Kinetic Sculptures
"Each sustainable innovation not only pushes the boundaries in relation to that particular packaging material, but increases the pressure on other materials to drive up recyclability, and drive down carbon footprints." Theres slightly more to it in practice, e.g. you have to fix up the remote message because target and reply port get swapped when receiving, arm64e needs some manual fiddling with thread register values to satisfy PAC, and so on, but its all very doable. I wrote a little tool called plparse that I have so far been reluctant to open-source because it emphasises the fact that there exist multiple plist parsers in iOS, and that they certainly dont all work the same. It takes an input file and any combination of -c, -i and -x args to parse the file with the CF, IOKit and XPC engines respectively. Running on the above file, we get: 3. Set your emptyDist (line 9) to your measurement from Part 2 minus 2 inches. For example, if your empty toilet paper distance from Part 2 was 19, then set emptyDist = 17. The code checks if the current distance is greater than emptyDist. If you want more advanced warning, use the distance with one roll left.
Right line paper - Apples final fix consists of introducing a new function called AMFIUnserializeXML, which is pasted into both and amfid, and is used to compare against the results of OSUnserializeXML and CFPropertyListCreateWithData to make sure they are the same. You can still include a sequence like in your entitlements and it will go through, but try and sneak anything in between those comments, and AMFI will tear your process to shreds and report to syslog:
Now, mach messages would essentially just be big binary buffers you send to the receiver, except they can also be used to transfer regions of memory as well as mach port rights. If you hold send rights to two mach ports A and B, you can send a message to B containing a send right for A, and once the receiver receives the message on port B, the kernel will clone your send right and insert the copy into that processes namespace. With receive and send-once rights you cant create clones, but you can move them. You can also create new send and send-once rights if you hold the receive right. And this isnt just some nice feature, this is something virtually every mach message uses Apart from being handles in processes, mach port rights can also registered on a few kernel interfaces. With most of those, theyre just kinda stashed away and ready to be looked up, and one thing that has such stashes are processes. They have three sets, in particular: Stephen Donnelly gave his most assured performance ever in the Dáil on Thursday night. The Health Minister was under fierce fire from David Cullinane of Sinn Féin. But as the night went on, it became clear Nphet did not signal a return to Level 5 in the course of their communications. Credit too to Cullinane for seeking out the truth. It was a good night for politics and openness.
But I figure those are more philosophical than technical in
nature. And while this entire story shows that it might be a good
idea to periodically ask ourselves whether the inaccuracies of
our mental models are acceptable, or something should be
documented and communicated more thoroughly, I really cant accuse
Apple of much here. Bugs like these are probably among the
hardest to spot, and I have truly no idea how the hell I was able
to find it while so many others didnt. So: code signatures.
When a binary wants to run on iOS, a kernel extension called
AppleMobileFileIntegrity (or AMFI) requires it to have a valid
code signature, or else it will be killed on the spot. What this
code signature looks like isnt important for us, all that matters
is that it is identified by a hashsum. This hash can be validated
in one of two ways: Of the tactics on both sides of the
politician spectrum he has said that it curdles my stomach, man I
have not appreciated it. Would Mr. McConaughey run as a Democrat
or a Republican? Thats as much a mystery as the meaning of his
soliloquy at the end of True Detective.
Part 1: Hardware Assembly of Toilet Paper Reminder - Now building on XML, we have property list, or plist for short: yet another general-purpose format for storing serialised data. You have arrays, dictionaries with key -> value pairs, strings, numbers, etc. Plist files exist in a bunch of different forms, but the only two that youll realistically see in an Apple ecosystem are the bplist binary format that are out of scope for this post, and the XML-based format. A valid XML plist can look something like this:
With our toilet paper holder, Full TP Holder reads 1 in and Empty TP Holder reads > 18 in. Your results may vary and you may also decide to use the measurement number for when one roll is left so you are alerted with a single roll, rather than when the holder is empty. It isnt news to anyone that many Texans abhor government interference. Mr. Perry seems to think that extends to keeping warm when temperatures drop to record lows. After a cataclysmic storm knocked out the states power grid in February, he said, Texans would be without electricity for longer than three days to keep the federal government out of their business a sentiment probably not shared by the friends and families of the 111 people (or more) who died of hypothermia and other storm-related causes. In an informal sense, its clear what it means for a binary to hold an entitlement. But how do you formally specify that? What would code look like that takes as input a process handle and an entitlement name and just returned a boolean saying whether the process does or does not have that entitlement? Luckily for us, XNU has precisely such a function in iokit/bsddev/: We can also ask ourselves how a bug like that could ever exist. Why the hell there are 4 different plist parsers on iOS. Why we are still using XML even.
There are cases though where the above entitlement magic isnt enough, specifically when you want to talk to a daemon that itself uses CF to parse entitlements. But with a bit of trickery, we can gain actual, legit entitlements that will be seen by all parsers. The current legislative session with Republicans in full control has been grim. You cant say they mind government interference when things like womens reproductive systems or voting rights are involved. People need time to adjust and prepare. If a business knows total lockdown is coming, it can try to find ways to stay profitable. State agencies need time to put social protection measures in place. You can't just close a country down by letter.