Apple's upcoming arm64 devices will prevent rwx access to memory,
but in turn provide a new per-thread way to switch between write
and execute permissions. This patch puts that system to use for
the WebAssembly subsystem.
The approach relies on CodeSpaceWriteScope objects for now. That
isn't optimal for background threads (which could stay in "write"
mode permanently instead of toggling), but its simplicity makes
it a good first step.
Background:
https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon
Bug: chromium:1117591
Change-Id: I3b60f0efd34c0fed924dfc71ee2c7805801c5d42
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2378307
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69791}
Generate a BTI instruction at each target of an indirect branch
(BR/BLR). An indirect branch that doesn't jump to a BTI instruction
will generate an exception on a BTI-enabled core. On cores that do
not support the BTI extension, the BTI instruction is a NOP.
Targets of indirect branch instructions include, among other things,
function entrypoints, exception handlers and jump tables. Lazy deopt
exits can potentially be reached through an indirect branch when an
exception is thrown, so they also get an additional BTI instruction.
Bug: v8:10026
Change-Id: I0ebf51071f1b604f60f524096e013dfd64fcd7ff
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1967315
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66751}
After support for ARCH_PPC was dropped, it became a subset of
ARCH_PPC64. If you compile for ppc64, then you set the ARCH_PPC64
define which also sets the ARCH_PPC define.
To be able to again support ppc (32 bit) those defines should be
split up again.
This commit only splits up the defines but does not introduce a
working ARCH_PPC variant.
Bug: v8:10102
Change-Id: I64e0749f8e5a7dc078ee7890d92e57b82706a849
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1989826
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66390}
Drive-by: Refactor FlushInstructionCache to its own header. This removes
dependencies of objects.cc and code.cc
Bug: v8:8562
Change-Id: If23f3b9d4f2068e08c61c0f4b070ecfe1b9a6cc0
Reviewed-on: https://chromium-review.googlesource.com/c/1456081
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59435}
Refactor the AllocateAssemblerBuffer helper for the new Assembler API.
This is the only non-mechanical part, all other callsites that create
Assembler instances can be trivially changed to the new API. This will
be done in a separate CL.
R=mstarzinger@chromium.org
Bug: v8:8689, v8:8562
Change-Id: I6c150748eeea778d9b70f41fd66fbb1221035a1b
Reviewed-on: https://chromium-review.googlesource.com/c/1415490
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58881}
This unifies the order of i-cache flushing and permission changing
throughout V8. According to cctest/test-icache flushing after the
permission change is not robust on some ARM32 and ARM64 devices.
There have been observed failures of {TestFlushICacheOfExecutable} on
some devices. So far there haven't been any observed failures of the
corresponding {TestFlushICacheOfWritable} test.
Also the order of flushing before the permission change is the natural
order in which the GC currently performs operations. Until we see
concrete data substantiating the opposite, the following is the
supported and intended order throughout V8:
exec -> perm(RW) -> patch -> flush -> perm(RX) -> exec
This CL tries to establish said order throughout the codebase.
R=ulan@chromium.org
TEST=cctest/test-icache
BUG=v8:8507,chromium:845877
Change-Id: Ic945082e643aa2d142d222a7913a99816aff4644
Reviewed-on: https://chromium-review.googlesource.com/c/1351025
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57869}
Port fed7bb501e
Original Commit Message:
This test cases ensures that it is possible to maintain a coherent
instruction cache by using {Assembler::FlushICache} in any order with
respect to changing page permissions via {SetPermissions}.
R=mstarzinger@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:6792
LOG=N
Change-Id: I23d5d0828dcbdd527aaa8708fa726a7cb5cbedfe
Reviewed-on: https://chromium-review.googlesource.com/c/1347511
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#57745}
This test cases ensures that it is possible to maintain a coherent
instruction cache by using {Assembler::FlushICache} in any order with
respect to changing page permissions via {SetPermissions}.
R=ulan@chromium.org
TEST=cctest/test-icache
BUG=v8:6792
Change-Id: I1778bbbe94b40856d9732a9990a931b5a956a439
Reviewed-on: https://chromium-review.googlesource.com/c/1344113
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57651}
