tmpfs is unusable

[Ismrbsmr]

(tldr: See 2 images, also attached IOS crash
report).

issue:

1. mounting tmpfs results in write only mode. (touch returns file name is too long within tmpfs).

2. Unmounting tmpfs will 100% result in a crash of the app.

3. abi level rm on a filedesc in tmpfs will crash the app. busybox rm will just report permission issue.(perhaps due to first checking permission before abi)?

4. basically tmpfs is unsuable.

5. IOS crash returns "Address Size Fault" .

Theories:

1. its the 'mount' syscall ( or 'mprotect' or suid bits called within mount param )

2. its the inode offsets of 32 bit (ISH-AOK) address, differing from the IOS kernel (64 bit) address.

3. It is due to the differing IOS and "linux"/ISH kernel paramaters of mount.

4. Executables safely alloc and free avail mem, so it must be mount paramaters.

5. it is due to the libmusl or busybox mount implimentation/param(related to suid bits).

Proposal:

1. making a block device driver in /dev/ to mount the tmpfs with mount params preset.
2. make every filedesc in tmpfs a buffered fifo.

Significance:

tmpfs will make some use cases 60-80% faster. (apt, fzf,tmux,etc...).

Maybe more rootfs distros can start init (related to tmpfs in fstab).

Let me know what you think and if you have any insight/leads to where to start to fix this issue.

Thank you,

ADDITION:

Another solution is to use mmap and specify a valid address(size and location) paramaters manually at the ISH-AOK Kernel when mount is invoked.