Freelist implementation was trying to mark pages executable (RX)
which does not respect possibility that it is working with RW mapping
which can't be directly marked as executable. It needed to use RO
permission instead if dual mapping is enabled.
This CL consolidates all code mentioning RX permission in one place:
VirtualMemory::WriteProtectCode so that we avoid this mistake in the future.
R=kustermann@google.com
TEST=tested by doing large reloads which cause more churn in code space
Change-Id: If99692cac3ce3ff54b907e4c43d7f26bae7439ff
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/435860
Commit-Queue: Martin Kustermann <kustermann@google.com>
Auto-Submit: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
* Disable RX workarounds on simulators: they cause host OS to crash;
* Remove Mac OS test for RX workarounds: it can cause host OS to crash;
* Remove old outdated code paths for OS versions that don't
need workarounds.
* Add code which detects whether workaround worked or not by intercepting EXC_BAD_ACCESS.
* Avoid using vm_remap in FFI callbacks when JITing, it does not work.
Instead restore old logic which manually copies page content, but adjust
FFI callbacks implementation to respect possible dual mapping.
This reworks changes done in commit
d194fcecaf after additional testing on a
wider range of hardware.
TEST=manually on physical devices and simulators
Change-Id: I339379386183c532fec25e88fa436ff0b970c2cf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/435120
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Heap references always point into R/RW mapping (this simplifies the
marker) and entry points are retargeted into RX.
To simplify implementation we assume that there are no image pages
created - which means we can always go from Instructions to the start of
the page and check where it is dual mapped to.
TEST=vm/dart/macos_dual_mapping_smoke_test and manually on physical
device
Change-Id: Idbe02b7b695b3c048072cf92f7d062f5ab6e1beb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/433940
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
We are no longer using Dart VM in a setting where this
matters as a security measure and it just complicates
portability for no benefit.
There is an indication that it is causing problems when
running Linux build of Dart VM under Docker on Mac OS X.
Fixes https://github.com/dart-lang/sdk/issues/54446
TEST=ci
Cq-Include-Trybots: luci.dart.try:vm-fuchsia-release-arm64-try,vm-fuchsia-release-x64-try
Change-Id: I11bdaa8faebaca1df6fd59097049bdaea9cb8e12
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/344581
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
This is the same metadata system that will support async callbacks. The
main thing this does is take the trampolines that used to be JIT only,
and use them in AOT too. This is partly a safety thing (there's some
extra checks that used to be skipped on AOT), but mostly just so that
the metadata system is unified between the sync and async callbacks.
More details about the design:
https://docs.google.com/document/d/1QDjyY_6wOTOgURwpeYMKU9qEz0gKxx2MUrdruC6Kp6c/edit?usp=sharing
I split this off the async CL. Some of the comments refer to async
stuff that doesn't exist yet, but it's coming immediately after this so
I didn't update them.
Change-Id: Icd5e86934ee9ae34c2c0e2ed2bbd1b928a7184ac
TEST=ffi_callback_metadata_test.cc and CI
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/302903
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Liam Appelbe <liama@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
This region is mostly unused after loading, but it may be accessed again if
- Isolate.spawn is invoke with isolate groups disabled
- A secondary snapshot produced by splitting is loaded
- An external typed data in the snapshot is accessed (usually a kernel file)
- Likely other cases
Even if these cases did not exist, the region is often part of a shared library and so unable to be released independently.
madvise(DONT_NEED) on this region will cause the OS to release the memory in this region but keep the address space reservation and mapping. If it is touched again, it will be brought back in from the file. If it is not backed by a file, such as malloc memory, it will be brought back in as zeros and the program will likely fail.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/44019
Bug: https://github.com/flutter/flutter/issues/92120
Change-Id: I315a049b0f7d440e181d0a5e87fa6770a2fd4f79
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/216580
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Don't allocate zones, timeline events or profile samples in the compressible region, since these allocations don't yeild compressed pointers and are competing for a limited resource.
TEST=ci
Bug: b/196510517
Change-Id: I4fc2f0d67060f927fa10d241b15b1cae3b73d919
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212400
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Also switch some CQ bots using blobs to ELF. Once all embedders have migrated, we will remove blobs
support entirely.
Change-Id: Ie5e8c1187ad6c1af362b5715daafd3641bc8cc0e
Cq-Include-Trybots:luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-bare-linux-release-simarm-try,vm-kernel-precomp-mac-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-precomp-android-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/116620
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Instead of implementing separate aligned and unaligned memory
allocation primitives for each OS, just change the unaligned allocator
into a wrapper around the aligned primitive.
While here, we can optimize the AllocateAligned logic slightly: if we
want an N-page-aligned allocation, we only need to increase the
allocation size by N-1 pages instead of N.
Notably, this means 1-page-aligned allocations don't require any extra
alignment pages, so the new logic behaves identically as before on
Android, Fuchsia, Linux, and macOS.
On Windows, it behaves slightly differently only in that unaligned
requests used to be handled as a single VirtualAlloc call with
MEM_RESERVE | MEM_COMMIT, but now they're handled as two separate
calls (reserve *then* commit). Naively, I don't expect this matters in
practice, but if it does, we can always add a fast path for
alignment==page_size_ without affecting the OS-independent API.
Change-Id: I42b2cf5dfc6e137546d8acfb6cc8939a01687948
Reviewed-on: https://dart-review.googlesource.com/c/91081
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
This CL assigns names to vmos formatted as "isolate space type" where
isolate is the name of the isolate, space is "oldspace" or "newspace",
and type is "code" or "data".
R=asiva@google.com
Review-Url: https://codereview.chromium.org/2929203002 .
i.e. #ifndef VM_WHATEVER -> #ifndef RUNTIME_VM_WHATEVER
This lets us remove a hack from the PRESUBMIT.py script that existed
for reasons that are no longer valid, and sets us up to add some
presubmit checks for the GN build.
R=asiva@google.com, rmacnak@google.com
Review URL: https://codereview.chromium.org/2450713004 .
-Pre-mark instructions when writing the snapshot.
-Write the megamorphic miss function to the snapshot.
-Add missing ExceptionHandlers for megamorphic miss code.
-Add missing C++ entry points.
-Relocate Function and Code entry_points_ when reading precompiled snapshot.
-Don't try to load a script again when running from a precompiled snapshot.
R=asiva@google.com
Review URL: https://codereview.chromium.org//1336763002 .
With the upcoming deletion barrier, every update of a pointer field must know whether the previous value was a valid pointer.
Currently, we always use StorePointer/StoreSmi, both for initialization and updates.
Initialization, and thus the potential for overwriting garbage values, appears in three places:
1. Object::Allocate/Foo::New.
2. Creating isolate from full snapshot.
3. Allocation in generated code.
Case 1 already null-initializes all underlying memory.
Case 2 is addressed by this CL by exploiting that:
i) fresh pages are zero-filled by OS, and
ii) freelist headers use only even values.
Case 3 is remains a TODO for future CLs.
(An alternative solution for case 2 would have been to add an init_foo method for every set_foo called.)
R=iposva@google.com
Review URL: https://codereview.chromium.org//792163003
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@42584 260f80e4-7a28-3924-810f-c04153c831b5
Vyacheslav Egorov