On 09/10/2023 14:37, Kees Cook wrote: > On Fri, Oct 06, 2023 at 02:07:16PM +0200, David Hildenbrand wrote: >> On 07.09.23 22:24, Guilherme G. Piccoli wrote: >>> Currently the kernel provides a symlink to the executable binary, in the >>> form of procfs file exe_file (/proc/self/exe_file for example). But what >>> happens in interpreted scenarios (like binfmt_misc) is that such link >>> always points to the *interpreter*. For cases of Linux binary emulators, >>> like FEX [0] for example, it's then necessary to somehow mask that and >>> emulate the true binary path. >> >> I'm absolutely no expert on that, but I'm wondering if, instead of modifying >> exe_file and adding an interpreter file, you'd want to leave exe_file alone >> and instead provide an easier way to obtain the interpreted file. >> >> Can you maybe describe why modifying exe_file is desired (about which >> consumers are we worrying? ) and what exactly FEX does to handle that (how >> does it mask that?). >> >> So a bit more background on the challenges without this change would be >> appreciated. > > Yeah, it sounds like you're dealing with a process that examines > /proc/self/exe_file for itself only to find the binfmt_misc interpreter > when it was run via binfmt_misc? > > What actually breaks? Or rather, why does the process to examine > exe_file? I'm just trying to see if there are other solutions here that > would avoid creating an ambiguous interface... > Thanks Kees and David! Did Ryan's thorough comment addressed your questions? Do you have any take on the TODOs? I can maybe rebase against 6.7-rc1 and resubmit , if that makes sense! But would be better having the TODOs addressed, I guess. Thanks in advance for reviews and feedback on this. Cheers, Guilherme
