32-bit allocations were scanning for available pages by shifting by the
length of allocation. This is incorrect since large allocations would
then only scan through the region in very large chunks. Especially if
MAP_32BIT was present. Instead scan by page size to ensure better fit.
This fixes X-Plane 11.
Also ensure we don't try to munmap a range unless the result is
MAP_FAILED, noticed we were trying to munmap ~0ULL
I accidentally committed a 32-bit range that was significantly smaller
than what it should be.
While the minimal range worked for simple cases, it didn't work for
anything complex.
Give it the full range it needs.
Fixes#1600
In the case of an AArch64 builder is using 16kb or 64kb pages like is
common on servers then it would fail to compile, even if the resulting
application would only ever run on 4k page hosts.
Resolve this by removing the build check and hardcoding 4kb pages for
each of our uses. We still require 4kb pages to run, so this mostly just
removes the weirdness where it is 16kb builder + 4k runner. Would have
broken some of our assumptions when running.
In the face of an application using MAP_FIXED_NOREPLACE AND the host
linux kernel doesn't understand this flag. Then we were falling down the
hint allocation path which would allocate a pointer in 64-bit space,
returning this pointer to a 32-bit userspace and breaking things.
Now when the hint fails with this flag, we know that it intersecting a
range and can early exit.
Adds a header only include utility folder that can be included from
everywhere.
Contains syscall helpers for older glibc and defines for older Linux
uapi headers missing some defines.
Migrates lingering instances of the old logger over to fmt where
applicable. This allows removing some of the old defines and functions.
The only remaining usages of the printf-based variant of the logger is
in Tests/LinuxSyscalls/Syscalls.cpp for the strace handling.
If MAP_32BIT was failing then we weren't checking error result
correctly.
This was causing us to crash.
Now add a helper function for checking syscall results since it is easy
to mess up.
Replaces the few cases where we were manually checking with the helper.
Fixes a Dota: Underlords crash
Previous we were just using an address hint to emulate MAP_32BIT.
Seemingly this behaviour has changed on AArch64 where it now isn't
guaranteed to scan up from the hint provided if exact allocation fails.
Now we pull in the full 32-bit allocator and add support for MAP_32BIT
in it. This limits the allocations there in to the first 2GB which Linux
expects.
Necessary for Mono's trampolines to work since it requires code to be in
the first 2GB on x86-64.
Ryan Houdek