On 13/11/2023 15:29, Eric W. Biederman wrote: > [...] > Currently there is a mechanism in the kernel for changing > /proc/self/exe. Would that be reasonable to use in this case? > > It came from the checkpoint/restart work, but given that it is already > implemented it seems like the path of least resistance to get your > binfmt_misc that wants to look like binfmt_elf to use that mechanism. > > Eric > Thanks Eric! I'm curious on how that would work: we'd change the symlink of the emulator? So, the *emulated* software, when reading that, would see the correct symlink? Also, just to fully clarify: are you suggesting we hook the new binfmt_misc flag proposed here to the internal kernel way of changing the proc/self/exe symlink, or are you suggesting we use the prctl() tune from the emulator, like the userspace changing its own symlink? One of the biggest concerns I have with this kind of approach is that changing the symlink actually...changes it - the binary mapping itself, I mean. Whereas my way was a "fake" change, just expose one thing for the emulated app, but changes nothing else... Cheers, Guilherme
