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}
