To locate whether a path is in the emulated list, EmulatedFDManager::OpenAt()
attemps to resolve the path. realpath() ends up calling readlinkat() on
every path component, which is a lot of syscalls for every open()
variant syscall. It also makes interaction with the rootfs complex and
error-prone.
There's a much easier way to do this: We just open the file without
emulation and check its real path via get_fdpath(). This is just one
readlink() syscall per open, instead of one per path component. If the
file turns out to be emulated (uncommon case), we swap out the fds.
This also decouples EmulatedFDManager from guest path resolution
entirely, so it will never fall out of sync with the RootFS logic.
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.
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.
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>
Which requires moving LinuxEmulation to its own independent folder as
well. Since both IRLoader and FEXLoader rely on it.
No functional change, just moves the the code around.
Asahi Lina