... by explicitly passing pointer compression cage base value to various
IsXXX() and map() calls in order to avoid using incorrect auto-computed
cage base value when applied to objects allocated in external code space.
This CL also introduces IsCodeObject(HeapObject) predicate which checks
the IS_EXECUTABLE bit in the page header's flags.
Bug: v8:11880
Change-Id: Ib44398c3125392e46e939044a9bd27e09d7944d5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3229368
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77459}
This CL adds features to pack/unpack map words.
Currently V8 cannot store extra metadata in object headers -- because V8
objects do not have a proper header, but only a map pointer at the start
of the object. To store per-object metadata like marking data, a side
table is required as the per-object metadata storage.
This CL enables V8 to use higher unused bits in a 64-bit map word as
per-object metadata storage. Map pointer stores come with an extra step
to encode the metadata into the pointer (we call it "map packing").
Map pointer loads will also remove the metadata bits as well (we call it
"map packing").
Since the map word is no longer a valid pointer after packing, we also
change the tag of the packed map word to make it looks like a Smi. This
helps various GC and barrier code to correctly skip them instead of
blindly dereferencing this invalid pointer.
A ninja flag `v8_enable_map_packing` is provided to turn this
map-packing feature on and off. It is disabled by default.
* Only works on x64 platform, with `v8_enable_pointer_compression`
set to `false`
Bug: v8:11624
Change-Id: Ia2bdf79553945e5fc0b0874c87803d2cc733e073
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2247561
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73915}
This is a reland of e28dadc207
The original failure was due to a stale Win32 bot. The reland failure
was due to idempotent task deduplication returning the exact same
failure. See crbug/1196064
Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}
Bug: v8:11460
No-Try: true
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: Id69311cf3267ebe1297fff159de0be48b15b65a3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806546
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73795}
This reverts commit 15c78b45a6.
Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32277/overview
Original change's description:
> Reland "[ptr-cage] Rename IsolateRoot to PtrComprCageBase"
>
> This is a reland of e28dadc207
>
> Relanding to see if Win32 rel failures from
> https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
> were infra flakes. Could not repro on try bots.
>
> Original change's description:
> > [ptr-cage] Rename IsolateRoot to PtrComprCageBase
> >
> > Currently, IsolateRoot is both the address of the Isolate root and the
> > base address of the pointer compression reservation. This CL teases the
> > two uses apart by renaming IsolateRoot to PtrComprCageBase.
> >
> > - In addition to V8_COMPRESS_POINTERS, add a
> > V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
> >
> > - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> > V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> > aliases to GetPtrComprCageBase.
> >
> > - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
> >
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> > Reviewed-by: Igor Sheludko <ishell@chromium.org>
> > Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
>
> No-Try: true
> Bug: v8:11460
> Tbr: ishell@chromium.org
> Tbr: rmcilroy@chromium.org
> Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169
> Reviewed-by: Shu-yu Guo <syg@chromium.org>
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73792}
Bug: v8:11460
Change-Id: Ifee92d622c43a91c15f45ef94ff739237bd2024b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806545
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73793}
This is a reland of e28dadc207
Relanding to see if Win32 rel failures from
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/overview
were infra flakes. Could not repro on try bots.
Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
No-Try: true
Bug: v8:11460
Tbr: ishell@chromium.org
Tbr: rmcilroy@chromium.org
Change-Id: I0a8c3a48999d6737c8c64d2c2703607f14f3fdd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806169
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73792}
This reverts commit e28dadc207.
Reason for revert: failed test262 tests;; see https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Win32/32275/steps?succeeded=true&debug=false
Original change's description:
> [ptr-cage] Rename IsolateRoot to PtrComprCageBase
>
> Currently, IsolateRoot is both the address of the Isolate root and the
> base address of the pointer compression reservation. This CL teases the
> two uses apart by renaming IsolateRoot to PtrComprCageBase.
>
> - In addition to V8_COMPRESS_POINTERS, add a
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
>
> - Rename GetIsolate* helpers to GetPtrComprCageBase. When
> V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
> aliases to GetPtrComprCageBase.
>
> - Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
>
> Bug: v8:11460
> Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
> Commit-Queue: Shu-yu Guo <syg@chromium.org>
> Auto-Submit: Shu-yu Guo <syg@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73790}
Bug: v8:11460
Change-Id: I19d0e28194fcdb28e89f129a7694ca3fe29fa17a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2806168
Auto-Submit: Francis McCabe <fgm@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#73791}
Currently, IsolateRoot is both the address of the Isolate root and the
base address of the pointer compression reservation. This CL teases the
two uses apart by renaming IsolateRoot to PtrComprCageBase.
- In addition to V8_COMPRESS_POINTERS, add a
V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE (vs SHARED_CAGE).
- Rename GetIsolate* helpers to GetPtrComprCageBase. When
V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE is true, the helpers remain as
aliases to GetPtrComprCageBase.
- Rename kPtrComprIsolateRootAlignment to kPtrComprCageBaseAlignment.
Bug: v8:11460
Change-Id: I1d715f678ce9a0b5731895612ca14f56579b1c48
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2783672
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Auto-Submit: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73790}
Adds a v8-gn.h file containing defines that are used in the
externally-visible headers files like v8.h. This must be included by
include/v8config.h which includes it if the GN flag
v8_generate_external_defines_header is on. (Currently off by default).
To enable the v8config.h file to be included without the other v8
headers (as required by cppgc), this moves it into its own header set
which sets up the include path correctly.
Also updates some headers to ensure v8config.h is included before using
externally-visible defines.
Bug: v8:11292
Change-Id: I5be634f4adfbef144bf684071461d64f1cb30899
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2608212
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72140}
Introduce an IsolateRoot class, which encapsulates the root address
needed for pointer decompression. This class is implicitly constructible
from both Isolate* and LocalIsolate*, allowing us to avoid templating
methods that can take both, or awkwardly creating a `const Isolate*`
from a `LocalIsolate*` just for getters.
Change-Id: I6d4b9492409fc7d5b375162e381192cb48c8ba01
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2440605
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70365}
When creating and inserting strings into the string table, we have to
make sure that the writes to the string's fields (including its
characters) are not reordered to after the write of the string into the
table itself.
Thanks TSAN!
Bug: chromium:1011762
Change-Id: Ib8a22e3980f6b5c57561ca23549c1462c4c017c8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2404767
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69838}
Rather than an Object array, use a Tagged_t array to store the
elements of the off-heap string table. This matches the old on-heap
string table's behaviour, and recovers memory regressions from that
work.
To be able to do this, this also introduces a new slot type,
OffHeapObjectSlot. This is because CompressedObjectSlot assumes that
the slot is on-heap, and that it can mask the slot location to
recover the isolate root. OffHeapObjectSlot doesn't define an
operator*, and instead provides a `load(const Isolate*)` method.
The other slots also gain this method so that they can use it in
slot-templated functions. Also, the RootVisitor gains an
OffHeapObjectSlot overload, which is UNREACHABLE by default and only
needs to be defined by visitors that can access the string table.
As a drive-by, fix some non-atomic accesses to the off-heap string
table, also using the new slot.
Bug: chromium:1109553
Bug: chromium:1115116
Bug: chromium:1115559
Bug: chromium:1115683
Change-Id: I819ed7bf820e9ef98ad5d5f9d0d592efbb6f5aa6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2352489
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69381}
... since decompression customization for MapWord is already
handled by HeapObject::MapField.
Bug: v8:9353, v8:9183
Change-Id: I009cdbbf8fc7e72029e1b9be54a0f0b73050e738
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1660475
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62188}
... and fix header includes to please the respective bot.
Drive-by-fix: decompression implementation is now MSVC friendly.
Bug: v8:7703, v8:8834
Change-Id: Iaf589138e5bafb32b0d9feab5cf074b71f241a3c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1505579
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60074}
