Executable V8 pages include 3 reserved OS pages: one for the writable
header and two as guards. On systems with 64k OS pages, the amount of
allocatable space left for objects can then be quite smaller than the
page size, only 64k for each 256k page.
This means regular code objects cannot be larger than 64k, while the
maximum regular object size is fixed to 128k, half of the page size. As
a result code object never reach this limit and we can end up filling
regular pages with few large code objects.
To fix this, we change the maximum code object size to be runtime value,
set to half of the allocatable space per page. On systems with 64k OS
pages, the limit will be 32k.
Alternatively, we could increase the V8 page size to 512k on Arm64 linux
so we wouldn't waste code space. However, systems with 4k OS pages are
more common, and those with 64k pages tend to have more memory available
so we should be able to live with it.
Bug: v8:10808
Change-Id: I5d807e7a3df89f1e9c648899e9ba2f8e2648264c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2460809
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#70569}
As a drive-by, enable tests that are safe for Arm32/64 to run.
Bug: v8:10833
Change-Id: I8fed5651399852f9ce8ba7d5acdb7ed27ca28e89
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467841
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70491}
Mostly a cleanup for x64.
Also enable two tests for Arm and Arm64 since they do not make use of
JSEntry frames.
Bug: v8:10833
Change-Id: Id6adadf582bdca0076460842ffe4ec856ca99393
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2381455
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69634}
With the new Turbofan variants (NCI and Turboprop), we need a way to
distinguish between them both during and after compilation. We
initially introduced CompilationTarget to track the variant during
compilation, but decided to reuse the code kind as the canonical spot to
store this information instead.
Why? Because it is an established mechanism, already available in most
of the necessary spots (inside the pipeline, on Code objects, in
profiling traces).
This CL removes CompilationTarget and adds a new
NATIVE_CONTEXT_INDEPENDENT kind, plus helper functions to determine
various things about a given code kind (e.g.: does this code kind
deopt?).
As a (very large) drive-by, refactor both Code::Kind and
AbstractCode::Kind into a new CodeKind enum class.
Bug: v8:8888
Change-Id: Ie858b9a53311b0731630be35cf5cd108dee95b39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2336793
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69244}
This is a reland of 137bfe47c9
Original change's description:
> [arm64] Protect return addresses stored on stack
>
> This change uses the Arm v8.3 pointer authentication instructions in
> order to protect return addresses stored on the stack. The generated
> code signs the return address before storing on the stack and
> authenticates it after loading it. This also changes the stack frame
> iterator in order to authenticate stored return addresses and re-sign
> them when needed, as well as the deoptimizer in order to sign saved
> return addresses when creating new frames. This offers a level of
> protection against ROP attacks.
>
> This functionality is enabled with the v8_control_flow_integrity flag
> that this CL introduces.
>
> The code size effect of this change is small for Octane (up to 2% in
> some cases but mostly much lower) and negligible for larger benchmarks,
> however code size measurements are rather noisy. The performance impact
> on current cores (where the instructions are NOPs) is single digit,
> around 1-2% for ARES-6 and Octane, and tends to be smaller for big
> cores than for little cores.
>
> Bug: v8:10026
> Change-Id: I0081f3938c56e2f24d8227e4640032749f4f8368
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1373782
> Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66239}
Bug: v8:10026
Change-Id: Id1adfa2e6c713f6977d69aa467986e48fe67b3c2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2051958
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#66254}
This reverts commit 137bfe47c9.
Reason for revert: https://ci.chromium.org/p/v8/builders/ci/V8%20Arm%20-%20debug/13072
Original change's description:
> [arm64] Protect return addresses stored on stack
>
> This change uses the Arm v8.3 pointer authentication instructions in
> order to protect return addresses stored on the stack. The generated
> code signs the return address before storing on the stack and
> authenticates it after loading it. This also changes the stack frame
> iterator in order to authenticate stored return addresses and re-sign
> them when needed, as well as the deoptimizer in order to sign saved
> return addresses when creating new frames. This offers a level of
> protection against ROP attacks.
>
> This functionality is enabled with the v8_control_flow_integrity flag
> that this CL introduces.
>
> The code size effect of this change is small for Octane (up to 2% in
> some cases but mostly much lower) and negligible for larger benchmarks,
> however code size measurements are rather noisy. The performance impact
> on current cores (where the instructions are NOPs) is single digit,
> around 1-2% for ARES-6 and Octane, and tends to be smaller for big
> cores than for little cores.
>
> Bug: v8:10026
> Change-Id: I0081f3938c56e2f24d8227e4640032749f4f8368
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1373782
> Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66239}
TBR=rmcilroy@chromium.org,mstarzinger@chromium.org,neis@chromium.org,georgia.kouveli@arm.com
Change-Id: I57d5928949b0d403774550b9bf7dc0b08ce4e703
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10026
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2051952
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66242}
This change uses the Arm v8.3 pointer authentication instructions in
order to protect return addresses stored on the stack. The generated
code signs the return address before storing on the stack and
authenticates it after loading it. This also changes the stack frame
iterator in order to authenticate stored return addresses and re-sign
them when needed, as well as the deoptimizer in order to sign saved
return addresses when creating new frames. This offers a level of
protection against ROP attacks.
This functionality is enabled with the v8_control_flow_integrity flag
that this CL introduces.
The code size effect of this change is small for Octane (up to 2% in
some cases but mostly much lower) and negligible for larger benchmarks,
however code size measurements are rather noisy. The performance impact
on current cores (where the instructions are NOPs) is single digit,
around 1-2% for ARES-6 and Octane, and tends to be smaller for big
cores than for little cores.
Bug: v8:10026
Change-Id: I0081f3938c56e2f24d8227e4640032749f4f8368
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1373782
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66239}
This new API uses the code pages rather than code ranges approach.
It's supported on arm32, as well as the previous two supported
platforms, x64 and arm64.
Deprecate the old API which only works on x64 and arm64 to reduce the
maintenance overhead of keeping both. Users of the old API should
migrate to the new one as it can be used all on supported platforms.
We keep the tests for the old API by ignoring deprecation warnings so
that we don't accidentally break it while it is still in the codebase.
Design doc:
https://docs.google.com/document/d/1VGwUult5AHLRk658VetwEHMOmDDxA2eDQs9lDFMZTE0
Bug: v8:8116
Change-Id: I1de8246a48fc1b4991603501ea6087db6b43fdd9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1969900
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65521}
