read the app-jit snapshot into this memory instead of directly mapping
the app-jit snapshot.
use MAP_JIT option only for executable pages and do not use it on iOS.
Change-Id: I8db6f29293677bbf36209473709077115b7b489e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113219
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Currently the initial mapping for the executable mapping is read-only.
Once the first instruction object was allocated into an OS page we would
map that page as RX. Any further allocations of instructions objects
into the same page would just end up mapping it to RX again (even though
it is already that way).
To avoid those additional protection calls we can map the executable
mapping RX from the beginning (it will be filled with zeros after
allocation).
Issue https://github.com/dart-lang/sdk/issues/37739
Issue https://github.com/dart-lang/sdk/issues/36097
Change-Id: Ib83f0be8ea8dacc86646c0a3c0335f4886516caa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/112244
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Until a better solution is found, disable dual mapping of code on docker
containers that fail setting exec permissions on dual mappings.
Change-Id: Ic7477e1ef70ae0ea4d0187284702d5a3ee594edf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/96668
Commit-Queue: Régis Crelier <regis@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
Auto-Submit: Régis Crelier <regis@google.com>
Reviewed-by: Alexander Aprelev <aam@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>
The Android, Linux, and macOS VirtualMemory implementations were
identical and using the same POSIX-standardized interfaces, so
deduplicate them into a common virtual_memory_posix.cc implementation.
Change-Id: I58a2aaa959aac69af52d9faba88865a4ef20d004
Reviewed-on: https://dart-review.googlesource.com/c/91080
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
asiva