So the reason fopen64 SEGV is because libselinux actually fopened /proc/filesystems before libclickpreload's init had run, hence libclickpreload's fopen64 wrapper would try calling a still NULL libc_fopen64.
I did an ugly workaround in fopen64 for now to discuss the nicest approach with Colin, see attached patch.
With the patch, I could click install a .click from a protected dir.
So the reason fopen64 SEGV is because libselinux actually fopened /proc/filesystems before libclickpreload's init had run, hence libclickpreload's fopen64 wrapper would try calling a still NULL libc_fopen64.
I did an ugly workaround in fopen64 for now to discuss the nicest approach with Colin, see attached patch.
With the patch, I could click install a .click from a protected dir.