This is done by consuming a single page at the end of the current sbrk
memory region. Then consuming any remaining bytes that could have
potentially ended up in it.
This ensures that glibc won't be able to return 64-bit pointers to
32-bit thunks once the remaining work is in place.
This has been a long time coming. The C interface has been a thorn in
our side for no reason for a long time.
The purpose of this step is to remove the C interface without changing
behaviour as much as possible. This means that with this commit there
are still some bad practices but the remaining issues will be solved
with followup PRs.
Primarily, we still have a `DestroyContext(CTX)` static function which calls
the Context implementation's `DestroyContext` and does a raw C++ delete.
Follow up PR will remove that, but I didn't want to touch it yet since
it'll require checking to ensure the unique_ptr changes play nice with
our allocator hooking. Which this is already a huge PR without trying to
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.
This is causing some heartburn with the hardlink.
- Removes some termux cmake list hacking.
- Removes the need to do post-install packaging fixups when hardlinks get dropped.
- Removes a custom uninstall target that was necessary before.
`std::filesystem::exists` is particularly gnarly in how it checks to see
if the file exists.
It allocates memory, it creates lists, it splits things, then eventually
checking the status
Remove all this overhead to help out minorly for applications that
execve a lot.
This creates a generic interface that FEXCore can use for timeline
profiling. This allows us to create a generic interface which the
backend details are hidden so we can support multiple timeline profile
APIs.
The only API supported right now is ftrace/gpuvis. Which is extremely
lightweight of an interface with minimal overhead.
We must be careful here since in most cases will will have dozens of
FEX instances running at any given time. So a timeline profiler like
Microprofiler can have major issues since that only ever expects a
single process at a time.
Not enabled by default but just needs the `ENABLE_FEXCORE_PROFILER`
cmake option set to enable.
Implements AT_PLATFORM: Ends up being `i686` or `x86_64` depending on
ELF arch
Implements AT_HWCAP and AT_HWCAP2
AT_HWCAP is just CPUID function 01h EDX result
AT_HWCAP2 only has two defined bits in it, which we don't support
either.
Implements AT_RANDOM
Previously we were just sticking hardcoded values in to this.
Now we pass along the host's AT_RANDOM, or we generate our own if that
doesn't exist
Fixes#788
Also in FEXLoader make sure to use `EraseSet` for these runtime options.
Fixes a bug where the config was being set to nothing, breaking the
ThunksDB configuration option.
We have separate configurations for the Application path versus the
application name we are using as a configuration choice.
Example 1: FEXBash "wine Crysis64.exe"
Previous APP_FILENAME will contain `/usr/bin/wine`, which is still used
elsewhere.
This new APP_CONFIG_NAME will contain `Crysis64.exe`
Example 2: FEXBash glxgears
Previous APP_FILENAME will contain `/usr/bin/glxgears`
APP_CONFIG_NAME will contain `glxgears`
We didn't have this exposed any other way before.
While we were getting the application name for the application layer, we
were failing to store the filename for telemetry.
Save the filename we get for application layers and store it for the
telemetry file.
Otherwise these were just alway ending up as wine or wine-preloader.
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
FEX always builds with PIE and we don't hit this issue anymore anyway.
If some application wants to inject a page in to the lower 32-bits then
we have no reason to complain about it anymore. Just let it go and
hopefully they know what they are doing.
Fixes#1559
If the user passes in an absolute path then check to see if it exists in
the rootfs before executing.
Useful for launching applications directly out of the rootfs with
FEXInterpreter.
In the case that the absolute path doesn't exist in the rootfs then
fallback to the host system as usual
Adds a header only include utility folder that can be included from
everywhere.
Contains syscall helpers for older glibc and defines for older Linux
uapi headers missing some defines.
Ryan Houdek