The idea is to mark all the branches and loads participating in array
bounds checks, and let them contribute-to/use the poisoning register.
In the code, the marks for array indexing operations now contain
"Critical" in their name. By default (--untrusted-code-mitigations),
we only instrument the "critical" operations with poisoning.
With that in place, we also remove the array masking approach based
on arithmetic.
Since we do not propagate the poison through function calls,
we introduce a node for poisoning an index that is passed through
function call - the typical example is the bounds-checked index
that is passed to the CharCodeAt builtin.
Most of the code in this CL is threads through the three levels of
protection (safe, critical, unsafe) for loads, branches and flags.
Bug: chromium:798964
Change-Id: Ief68e2329528277b3ba9156115b2a6dcc540d52b
Reviewed-on: https://chromium-review.googlesource.com/995413
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52883}
This CL changes the poisoning in the interpreter to use the
infrastructure used in the JIT.
This does not change the original flag semantics:
--branch-load-poisoning enables JIT mitigations as before.
--untrusted-code-mitigation enables the interpreter mitigations
(now realized using the compiler back-end), but does not enable
the back-end based mitigations for the Javascript JIT. So in effect
--untrusted-code-mitigation makes the CSA pipeline for bytecode handlers
use the same mechanics (including changed register allocation) that
--branch-load-poisoning enables for the JIT.
Bug: chromium:798964
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: If7f6852ae44e32e6e0ad508e9237f24dec7e5b27
Reviewed-on: https://chromium-review.googlesource.com/928881
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52243}
Turn cases where we are multiplying with a power of two into a left shift. We
hit this optimisation roughly 500 times in the snapshot.
Bug:
Change-Id: Ibd3104a3dbe49f247a2d84db94891f6e3a897026
Reviewed-on: https://chromium-review.googlesource.com/763229
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#49306}
Contributed by kanghua.yu@intel.com.
Bug: None
Change-Id: I5651ef38eb0c08deb97770a5eaa985dba2dab9a9
Reviewed-on: https://chromium-review.googlesource.com/604648
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Pan Deng <pan.deng@intel.com>
Cr-Commit-Position: refs/heads/master@{#47968}
