With the previous Copy{To,From}User helpers we need to actually
implement the handlers correctly. We want something that is a bit
lighter so we don't need to implement the faulting path in the syscall
handlers.
Implements a handful of helpers that just check for readable and
writable capability which can be thrown in to an assertion handler that
is zero cost in release mode.
Readable is checked by just attempting to read all bytes.
Writable is checked by attempting to read each byte and writing it back
to the same location.
Uses these helpers in x64/FD.cpp to showcase how they will be used to
detect EFAULT. Tested locally that they work correctly by writing some
small tests for the syscalls that expect EFAULT.
This has been leaked state to FEXCore for quite a while. FEXCore never
actually needed this information, moves the bits to the frontend that
are necessary.
Minor behaviour change that `RunUntilExit` now just assumes the primary
thread is using it. This behaviour is on the chopping block to get
removed next anyway.
Instead of passing the TID back to the exit handler, just pass the whole
thread object. This will allow some cleanups with the frontend thread
tracking soon
NFC
We support leaf functions now, so add the few that were calling for it.
We will be gaining support for the xsave ones relatively soon, so its
good to have them supported.
Also deletes a couple of cdt/cqm things that aren't exposed and we won't
be supporting.
Removes a global static initializer for the vector and its atexit
handler.
This handler array can be consteval similar to the x86 tables so it can
be generated entirely at compile time.
This causes a global initializer that registers an atexit handler.
Be smarter, use an std::array and pass its data around using a span
instead.
Removes the global initializer and removes the atexit installation
At the moment we always run ctest with max number of cpus. If
undefined, it will keep current behaviour, otherwise it will
honour TEST_JOB_COUNT.
Therefore to run ctest one test at a time, use
`cmake ... -DTEST_JOB_COUNT=1`
Some applications don't measure rdtsc correctly and instead use cpuinfo
to get the CPU core's base clock speed. Which for most x86 CPUs is the
base clock speed which also matches their cycle counter speed.
Did this as a quick test to see if this would help `Unbound: Worlds
Apart` stuttering while BinaryNinja was disassembling the binary.
Turns out the game doesn't use cpuinfo for its cycle counter speed
determination, but it is good to implement this regardless.
Fixes#3691
We weren't checking if the file was empty before using its `at` function
member. This was causing an early crash if the config file existed but
was empty.
Consolidates the three locations that copy and pasted the json allocator
tools and adds an empty check for all of them.
Also adds two missing checks to the ThunksDB handler that could have
resulted in the same crash if ThunksDB was an empty file.
Pulled from the seccomp WIP PR where it pulls this object more frequently.
Since it is an opaque frontend pointer it needs to be cast and we
already have a few locations that use it.
No functional change.
Fixes#3675
This was the first time I've ever actually dived in to this code and this
function melted my brain a bit while reading it. It was trying to be too
smart in tracking VMA splits, but if it split right at the end of a VMA
range it would then add a new range at the end where one already
existed. This then caused us to have overlapping VMA ranges and it would
completely break our SMC tracking since all tracking in the map must not
overlap.
Instead of being too smart, just break it down in to 4 merge strategies,
three of which are one shot. This is significantly easier to reason
about and each strategy is mostly self-contained. The fourth strategy in
the list is the most complex since it requires multiple steps since it
needs to walk multiple VMAs.
To help test this I added some sanity checking code that proved
invaluable to ensure everything was correct. That's not getting merged
since the overhead is too much to run, but good to have available. Diff
for this is at
https://gist.github.com/Sonicadvance1/1ee60101ed0742b971a476fadbb51083
When asked to not follow the symlink, FEX needs to return data about the
symlink itself rather than following to the target executable. In that
case we need to return symlink information otherwise games that sanity
check can break.
This is what happened with Darwinia in #3662.
We return the FEXInterpreter symlink information in this case since it
doesn't return any information that is relevent to leaking emulator
state. Once the application asks to follow through to the symlink target
is when we will replace.
Also adds a unit test to ensure we don't break it.
In preparation for seccomp execve inheritance.
We are going to need to add a new environment variable earlier in the
execve sequence to handle inheritance in the case of binfmt_misc.
No functional change in regards to envp handling.
Minor change around execveat with FD without binfmt_misc. In the case
that execveat returned an error and we did a `dup` of the FD then we
would have an FD leak. Make sure to close the duplicated FD in that
instance.
alternative to #3638. this is theoretically better for side-by-side diffs. in
practice it may make other diffs worse since all the \'s change when part of the
macro change.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Arm64ec introduced the InterruptFaultPage which is lower overhead since
instead of ldr+str it just turns in to a single str. We were already
allocating the space, FEXCore and the frontend signal delegator just
needed to be updated to understand the new location.
We can additionally use this in the future if we want to make deferred
async signals INSIDE the JIT only cost a single str as well.
A bit of refactoring necessary before we can move the remaining Linux
specific code to the frontend.
Most of this taken from #3535 but attempting to be NFC as much as
possible.
A feature of FEX's JIT is that when an unaligned atomic load/store
operation occurs, the instructions will be backpatched in to a barrier
plus a non-atomic memory instruction. This is the half-barrier technique
that still ensures correct visibility of loadstores in an unaligned
context.
The problem with this approach is that the dmb instructions are HEAVY,
because they effectively stop the world until all memory operations in
flight are visible. But it is a necessary evil since unaligned atomics
aren't a thing on ARM processors. FEAT_LSE only gives you unaligned
atomics inside of a 16-byte granularity, which doesn't match x86
behaviour of cacheline size (effectively always 64B).
This adds a new TSO option to disable the half-barrier on unaligned
atomic and instead only convert it to a regular loadstore instruction,
ommiting the half-barrier. This gives more insight in to how well a
CPU's LRCPC implementation is by not stalling on DMB instructions when
possible.
Originally implemented as a test to see if this makes Sonic Adventure 2
run full speed with TSO enabled (but all available TSO options disabled)
on NVIDIA Orin. Unfortunately this basically makes the code no longer
stall on dmb instructions and instead just showing how bad the LRCPC
implementation is, since the stalls show up on `ldapur` instructions
instead.
Tested Sonic Adventure 2 on X13s and it ran at 60FPS there without the
hack anyway.
This environment variable had an incorrect priority on the configuration
system. The expectation was higher priority than most other layers.
Now the only layer that has higher priority is the environment
variables.
FEXCore includes was including an FHU header which would result in
compilation failure for external projects trying to link to libFEXCore.
Moves it over to fix this, it was the only FHU usage in FEXCore/include
NFC
This is no longer necessary to be part of the public API. Moves the
header internally.
Needed to pass through `IsAddressInCodeBuffer` from CPUBackend through
the Context object, but otherwise no functional change.
Same situation as the last stack leak memory fix, this is fairly tricky
since it is dealing with stack pivoting. Fixes the memory leak around
pthread stack allocations, making memory usage lower for applications
that constantly spin-up and destroy threads (Like Steam).
We need to let glibc allocate a minimum sized stack (128KB and we can't
control it) to work around a race condition with DTV/TLS regions. This
means we need to do a stack pivot once the thread starts executing.
We also need to be careful because the `PThread` object is deleted
inside of the execution thread, which was resulting in a use-after-free
bug.
There are definitely some more memory leaks that I'm still fighting, and I have
noticed in my abusive thread creation program that we might want to
change some jemalloc options to more aggressively cut down on residency.
This is just one out of many.
I remember seeing some application last year where they closed a FEX
owned FD but now I don't remember what it was. This can really mess us
up so add some debug tracking so we can try and find it again.
Might be something specifically around flatpack, appimage, or chrome's
sandbox. I have some ideas about how to work around these problems if
they crop up but need to find the problem applications again.
This may be useful for tracking TSO faulting when it manages to fetch
stale data. While most TSO crashes are due to nullptr dereferences, this
can still check for the corruption case.
This was a funny joke that this was here, but it is fundamentally
incompatible with what we're doing. All those users are running proot
anyway because of how broken running under termux directly is.
Just remove this from here.
The NVIF ioctl isn't publicly described in the nouveau headers and it is
required for anything to work with Nouveau.
Pass the ioctl command through without modification and hope that this
ioctl is architecture agnostic.
Reimagining of #3355 without any json generators or new concepts.
Fixes some mislabeling of system calls. Some getting inlined when they
shouldn't be, a lot not getting inlined when they can be.
This really cleans up the syscall implementation, all syscalls that can
be passthrough implementations require a very small two line
declaration.
Additionally cleans up a bit of implementation cruft where some
passthrough syscalls were using the glibc syscall handler, and some were
using the glibc implementation. We have had multiple issues in the past
where the glibc implementation does something subtly different than the
raw syscall and breaks things. Now all passthrough handlers do a system
call directly, removing at least one indirection and some ambiguity.
This makes it significantly easier to add new passthrough syscalls as
well. Only need to do a version check and add the three lines per
syscall. Which there are new syscalls incoming that we will want to add.
Tangible improvements:
- Syscalls are lower overhead than ever.
- When I'm adding more syscalls I have less chance of mucking it up.
Ryan Houdek