ELF headers were read unconditionally because doing so was assumed to be cheap
(as the guest app would read them anyway shortly after). However, relocation
parsing was added since then, which has less predictable performance due to
crossing page boundaries and reading larger amounts of memory. It might be
possible to make the underlying code more efficient, but until that's done
it's better to skip this logic unless needed.
Closes#5390
Disables THP on some key locations that are fairly sparse
- rpmalloc
- This is the big one as this allocates some heavy sparse buffers.
- CallRet stacks
- These get in the hundreds of megabytes, while not being sparse they
trend towards only using a handful of pages and ballooning to 2MB
per thread is quite heavy.
- Lookup cache
- L1 specifically gets hit here which adds a decent chunk of overhead
due to sparsity.
Win32 for all of these also aren't handled, but that will need to be a
followup.
Add a no-op for zero length in ChangeProtectionFlags.
This fixes AMD Vivado 2025.2 which tries to mprotect with 0 as size and merge strategies fails:
```
Unexpected ChangeProtectionFlags Merge strategy! [0x400000, 0x401000) Versus [0x0, 0x0)
```
We were passing through 32-bit signed values to the 64-bit handler,
which isn't valid and we need to make sure to sign extend.
I don't think this fixes anything because negative values aren't valid,
but a negative could have been interpreted as a large positive without
this.
So WTF can see their usage. Previously didn't add this due to some weird
madvise bug that delete anon names, but that seems to be fixed in a
newer kernel.
rpmalloc is currently very aggressively configured which causes
significant reductions in resident memory over jemalloc.
In Bayonetta's title screen it went from 963MB down to 834MB resident.
When an anonymous FD is passed to execveat that has the CLOEXEC flag
set, then binfmt_misc fails with ENOENT.
Workaround this limitation by duplicating the FD, stripping its CLOEXEC
flag in the process.
For #5234
This was a nasty race condition where each thread could be accessing the
DRM cache at any given moment. Move it over to a per thread object that
is only allocated once it gets used.
Also removes an `atexit` registration that contributes to crashing on
exit.
Applications can use this to ensure they've grabbed the whole XSTATE
correctly. UML uses it to determine if the FPState was correctly saved.
Also adds a unittest to ensure the same correct behaviour.
For #5206
Turns out the Linux kernel's definition of `MINSIGSTKSZ` and glibc's
definition of `MINSIGSTKSZ` don't match.
The linux kernel has a massive comment about it in `arch/x86/kernel/signal.c`.
Also adds a unittest for it.
For #5206
Steam started taking advantage of newer fcntl commands, in particular
`F_CREATED_QUERY`. This was causing our fcntl handler for 32-bit
processes to assert out.
Fixes the handler so it passes all other fcntl commands forward, just
like the Linux kernel does. Splits the 32-bit handler to explicitly
ignore a handful of commands just like the Linux kernel.
Fixes an assert that Steam was hitting.
This allows the context and parent thread objects to be created earlier,
allowing the VDSO and ELFCodeLoader mapping functions to have a thread
object for tracking memory mappings through the regular guest routines.
This means that we no longer need to do any form of deferred handling
for code caching as all the state is ready early in the initialization
process.
A little bit of care needed to be taken to ensure we still close the
ELFCodeLoader's FDs later and that VDSO unmapping happens before tearing
down the parent thread, but overall this is mostly just passing the
InternalThreadState object around as normal.
I couldn't find any functional regression from this change alongside
code caching, but it would be good for @neobrain to double check this.
- Do compiler/architecture checks EARLY, don't waste time doing random
configuration stuff if the user can't even compile in the first place
- MSVC is unsupported, I assume? So add a check to disallow. There's
literally no MSVC or MSC_VER checks anywhere, so...
- Rather than using the MSVC architecture definitions, use our own
`ARCHITECTURE_arm64` et al. Hijacking existing "standard" definitions
is a very bad idea. Also makes it more readable in CMake
- Change the x86 host check to `x86|amd64`. Some systems still refer to
themselves as x86 despite being 64-bit for... reasons, and I saw one a
very long time ago that referred to it as amd64. This should
basically never come up, nor is it really relevant given that FEX is
for arm64... but it kinda annoyed me so whatever.
TODOs:
- Should we check `CMAKE_SIZEOF_VOID_P (equal) 64`? I don't think anyone
is even trying to compile this thing on armv7 or older, but might as
well? maybe?
- What's the status of *BSD, Solaris, macOS? Technically macOS does
support Wine, not sure about the others.
Signed-off-by: crueter <crueter@eden-emu.dev>
The ELF tracking thing has an expectation that only portions of ELF
files that are described in the program headers will be mapped
executable. This doesn't hold true as programs will remap random
portions of ELF files as executable. In the case that this occurs, don't
assert out and instead print a warning.
This was discovered as Node.js remaps a portion of itself executable
that isn't described as such in the program headers. I also have a local
unittest that exposes the same problem. I had discovered same problem in
some other program with #5038.
Also fixes a bug where sometimes completely anonymously mapped
executable sneak in and cause a crash, which is kind of silly.
Tony Wasserka