Removes a global initializer and atexit registration
Ownership of this data has always been the frontend and the config
system, we just used these static vectors as a side-channel.
This was a bit confusing to read and I had always expected to change
this at some point.
Previous:
```
[INFO][1579518391560577][1601857.1601857] clone: Unsupported flags w/o CLONE_THREAD (Shared Resources), 4100
```
Now:
```
[INFO][1590468.992593376][1629501.1629501] clone: Unsupported flags w/o CLONE_THREAD (Shared Resources), 4100
```
It looks like `SYSTEMD_EXEC_PID` can leak through to the executable
environment in regular situations. Instead let's key off of
`INVOCATATION_ID` which doesn't leak through.
Fixes an edge case behaviour where FEXServer wouldn't daemonize in some
systemd environments.
Fixes this file compiling on musl at least.
POLLREMOVE usage here is technically incorrect as it shouldn't be OR'd
with other flags.
But it is also additionally wrong here because the Linux kernel doesn't
even support this flag anymore, so it doesn't change behaviour.
Fixes#2136
This is a fairly tricky edge case to support with FEX.
If execveat is used with AT_EMPTY_PATH then the application can pass an
FD to execve instead of a filename. This includes FDs that have been
deleted from the disk so the child process can't open it by filename
anymore.
To work around this limitation, we need to pass the FD to the new FEX
process and open it directly, similar to how binfmt_misc works with FDs.
The FD will get passed through environment variables, which the new
process will check for and then remove the variable from the
environment.
Lots of prickly edge cases to support here.
Without binfmt_misc:
- Passes the FD to FEXLoader directly.
- Requires duplicating the FD if it has O_CLOEXEC on the FD.
With binfmt_misc:
- Shebang file, pass directly to FEXLoader, just like without binfmt.
- x86 ELF Files, rely on the kernel's binfmt_misc support here.
- Unsupported ELF files, let kernel handle it through binfmt_misc
Argument handling:
- The application can pass in no arguments.
- Means our application configurations were failing to find a config
- Also various checks in the frontend were failing.
- If opened through an FD, find the symlink for that FD for the
application configuration instead.
Side note:
Fixed a performance issue in execve where when we were checking for file
format support. Either ELF or Shebang files, we were reading the /whole/
file upfront. We only need to read a header worth of ELF files, and only
257 bytes if it is potentially a shebang file. Should dramatically
reduce some application's execve times.
Two changes here.
- Make the mount path follow server temp folder requirements.
- Will be mounted in `/tmp/` or `$XDG_RUNTIME_DIR/` now
- Switch the FEXServer socket to an "abstract" AF_UNIX socket.
- If the socket is in `/tmp/` then systemd will put the service in a
private `/tmp` folder that only exists for the service.
- If the socket is in `$XDG_RUNTIME_DIR` then pressure-vessel can't
chroot anymore since they make their own runtime directory.
- If it is in `$HOME/.fex-emu/` then it breaks usage where the
filesystem is a mount that doesn't support AF_UNIX like sshfs.
The only reasonable thing to do is to switch over to `abstract` sockets
which will work in all cases.
Tested with pressure-vessel and systemd and now it works in all
situations.
Chrome seems to like sending us invalid packets of data sometimes. With
an invalid packet type just skip parsing the data entirely.
Fixes an infinite loop in Vampire Survivors.
pidfd_open was added in kernel 5.3 so older kernel devices weren't able
to use `FEXServer -w`. If the syscall doesn't give us an FD to the
process, then use a pipe instead.
Since we are only polling for the FD to hangup this works for us.
Depending on the operation we will do a vector insert or removal while
iterating over the vector.
Fixes a use after free that asan found when insert caused the vector to
resize.
Due to glibc issues around static applications doing dlopen this is a
fundamentally broken option and no longer supported by FEX.
Remove the option entirely as to not be confusing.
We kept this around initially for chroot support, but with our RootFS
mounting AArch64 folders inside the chroot this isn't necessary anymore.
It can be useful to know in tooling when the current active FEXServer
has exited.
Two things can happen when this command is run.
No FEXServer is active, returns immediately.
A FEXServer is active, we query for a pidfd from the active server, then
we wait until it exits.
Both instances of this is valid to use.
This is a relatively invasive change since multiple things needed to
happen at once.
* Socket based logging is removed
* Logging has been replaced to only support stdout, stderr, and server
* Server is now default and replaces what FEXLogServer did
* Server logging now uses a pipe instead of a socket
* Can be faster than stderr and stdout since the application doesn't
need to wait on terminal output
* FEXMountDaemon has been removed
* Functionality has been merged in to FEXServer
* FEXServer is always executed on FEX initialization time
* Similar in behaviour to Wine's wineserver
* Can explicitly start this before using FEX for logging purposes
* Stays around until all instances of FEX exit
* Will stick around for a short amount of time in case of spurious
execution
* FEXServer will soon be extended to do more than logging and squashfs
mounting
* FEX rootfs scripts will need to be updated to support this path
* Just means rbinding the /tmp folder and forcing a FEXServer instance
to be alive
* Pressure-vessel works fine in this case since FEXServer will already
be running
* It already rbinds the host /tmp folder which is why this works
