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>
Fixed offset x86 code doesn't quite solve the issue, so adjust this
heuristic just to get instcounci to stop flaking.
This code is going to heavily change soon anyway so +50 doesn't change
much.
undefined instructions are expected to return SIGILL, while implemented
instructions that aren't available in CPL-3 are expected to SIGSEGV.
Noticed this while testing out CPU-Z, it installs a kernel module and
does a bunch of `RDMSR` and `OUTS` instructions. Decided to walk through
the rest of the instructions in the `System Instruction Reference`
section.
Turns out there's a bunch of oddities in there that we don't support.
First step is to go through all the explicitl SIGILL and SIGSEGV and
implement a test for them.
Next step will be implementing the remaining operations that are
considered "System" operations but are still available in CPL-3.
This list includes:
- lar
- lgdt
- lsl
- sidt
- sldt
- stac
- clac
- verr
- verw
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.
RA should not depend on whether we support AVX, that's a huge layering
violation! and fortunately, it does not.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Aside from its own self-test, the parser is unused and should remain that way,
since it's a maintenance burden with no real benefit. Burn it.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
SRA is fundamentally about hardware registers, not stores into a
software-defined context. So, it should take a register instead of an offset.
This makes all the unaligned special cases unrepresentable (by design).
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
While the ARM64EC ABI mostly matches FEX's SRA, the stack still needs to
be switched to the emulator stack and target RIP stored into the FEX
context before jumping to the dispatcher loop.
These callbacks are used for code invalidation and setting the right
emulated CPU features, neither of which are necessary for syscalls made
from within FEX. Avoid calling them to prevent deadlocks caused by
nested locks during compilation.
Alyssa Rosenzweig