This doesn't fully fix#5912 but gets a step closer. Instead of just
hashing the filename, hash in the build-id as well when it exists.
This isn't all encompassing because the build-id may not exist in all
cases. Crypt Of the Necrodancer for example doesn't ship with the
build-id on their 64-bit build. Although their legacy 32-bit build had
it.
The build-id is always a hash, depending on tool it is either 64-bit or
160-bit in all the executables I found. Although it can be anything so
make sure to be flexible enough to support everything.
When binfmt_misc is not visible, execve of an x86 ELF reexecs FEX by path.
That drops the caller-supplied argv[0] and asks the next FEX to reopen the
file through RootFS. Keep the resolved ELF in FEX_EXECVEFD, retain argv[0],
and mark the FD as path-backed so /proc/self/exe stays the real path.
Anonymous memfd execution is unchanged.
I forgot on Linux by default we didn't have the syscall instructions
count as block end. Change this so that it counts as block end now.
This has the additional benefit that now the frontend needs to modify
the RIP manually as well which is fine as it's what arm64ec and wow64
does.
Also add back the UnimplementedOp in RDPID that accidentally got caught
up. Also increment DiskCache version as both changes will change
codegen.
Fixes#5942
We would check the FileID of mapped sections, but BSS is an anonymous mapping.
Grab the ELF image extents when we parse the file, and add an additional check
to the relocation filter to bail out additional relocs if we know that size.
The JIT was doing a bunch of additional work where it was saving and
restoring registers and then juggling the arguments back in to a stack
frame. All of this is nonsensical without the optimization where we
could call syscalls inline without a stack frame.
Instead remove this optimization entirely and behave like a "generic"
syscall path always. The Linux syscall handler now pulls the arguments
out of the CPU context directly and stores the result back in to RAX
directly as well.
This has knock-on effects where technically syscalls are
going to be slightly faster because no stack frame setup for the
arguments, but additionally we are going to be able to have syscalls be
proper serialization points where we can interrupt the syscall and
long-jump out without problems.
Bumps the DiskCache version again because it causes codegen to change.
We actually never use this anymore, we instead always pass zero for
both, and then rely on the thread inheritance model or setting the
values manually. Now that we expose visibility of the
InternalThreadState to the frontend they just access it directly.
Just a smidge of cleanup, NFC.
Previously this would result in a larger amount of words specified than
necessary.
e.g. Given nfds = 1:
With AlignUp(1, 32) / 4, we'd end up with supposedly eight words, when it
should only be one word.
On the other extreme, given a full fd set of 1024 fds, then we'd end up
with 256 words, when it should only be 32.
CopyToUser doesn't return the number of bytes copied, but rather returns
0 to indicate success, otherwise a fault has occurred (and the SIGSEGV
handler has set X0 to EFAULT)
Ryan Houdek