Newly-launched processes randomly spawn frozen (signal STOPped)

[badger200]

(Cross post of Issue #2291 · pwn20wndstuff/Undecimus)

This jailbreak tampers with launchd (replacing it altogether and spawning the real thing as a subprocess), randomly causing newly-launched processes to spawn in the frozen state. 👀 ⚠️ It’s definitely the jailbreak’s fault, as the source code has stuff specifically freezing launched processes for some reason. It tries to resume them all, but clearly is less than 100% successful.

Using ps aux | grep ' T. ', look for processes with "T" (or T+) for Status. They are frozen with signal STOP. Identical to manually freezing a process via kill -STOP (pid).

I constantly have to search for these and issue kill -CONT (pid), and often I experience very odd glitches where random parts of iOS fail, until I discover which process has been frozen today, and when I CONTinue it, suddenly everything I've tried doing that failed, all executes in a row, as if it has all been queued up/hung, waiting for that frozen process. You’d be surprised at all the nasty bugs that stem from various seemingly-unrelated system services being frozen..

iPad Pro 11" A12X iPad8,4 Cellular 1TB
iOS 14.4
unc0ver 8.0.2

Place an "x" between the brackets if true:

• this is a bug others will be able to reproduce
• [unknown] this issue is present with all tweaks uninstalled(except for default packages) or disabled
• [unknown] this issue is present after a rootfs restore
• this issue is present on the latest version of unc0ver

Doing terminal compiling large projects like LLVM or even smaller ones, using make -j4 for multi core, it's almost impossible to ever compile a project without numerous make processes getting frozen and halting the entire build until I keep hunting them down. (I've made bash shell aliases to make this quicker). Oddly it seems much less likely if I compile a single thread/core.

Use bash alias stopped='pg '\'' T. '\''' , then you can just type stopped to find them.

Oddly in CocoaTop64 these frozen processes show a task Status of "DB" which I'm not sure what it means.

Is there anybody who DOESNT experience this??? For example, is there anyone who can compile a large (5 minute+) program build spanning 100+ objects, and successfully do it 3x in a row, with zero freezes?

In my opinion this unc0ver 8 / Fugu14 is the least stable jailbreak I've ever used. I'm still grateful as hell for it though. But man I get kernel panics every 3-7 days...