Commit Graph

3 Commits

Author SHA1 Message Date
Paolo Severini
969cb0c7a5 Reland "V8 x64 backend doesn't emit ABI compliant stack frames"
This is a reland of 3cda21de77

Original change's description:
> V8 x64 backend doesn't emit ABI compliant stack frames
> 
> On 64 bit Windows, the OS stack walking does not work because the V8 x64
> backend doesn't emit unwinding info and also because it doesn't emit ABI
> compliant stack frames. See
> https://docs.google.com/document/d/1-wf50jFlii0c_Pr52lm2ZU-49m220nhYMrHDi3vXnh0/edit
> for more details.
> 
> This problem can be fixed by observing that V8 frames usually all have the same
> prolog and epilog:
> 
> push rbp,
> mov rbp, rsp
> ...
> pop rbp
> ret N
> 
> and that it is possible to define XDATA (UNWIND_CODEs) that specify how Windows
> should walk through V8 frames. Furthermore, since V8 Code objects are all
> allocated in the same code-range for an Isolate, it is possible to register a
> single PDATA/XDATA entry to cover stack walking for all the code generated
> inside that code-range.
> 
> This PR contains changes required to enable stack walking on Win64:
> 
> EmbeddedFileWriter now adds assembler directives to the builtins
> snapshot source file (embedded.cc) to emit additional entries in the .pdata and
> in the .xdata section of the V8 executable. This takes care of stack walking
> for embedded builtins. (The case of non-embedded builtins is not supported).
> The x64 Assembler has been modified to collect the information required to emit
> this unwind info for builtins.
> 
> Stack walking for jitted code is handled is Isolate.cpp, by registering
> dynamically PDATA/XDATA for the whole code-range address space every time a new
> Isolate is initialized, and by unregistering them when the Isolate is
> destroyed.
> 
> Stack walking for WASM jitted code is handled is the same way in
> wasm::NativeModule (wasm/wasm-code-manager.cpp).
> 
> It is important to note that Crashpad and Breakpad are already registering
> PDATA/XDATA to manage and report unhandled exceptions (but not for embedded
> builtins). Since it is not possible to register multiple PDATA entries for the
> same address range, a new function is added to the V8 API:
> SetUnhandledExceptionCallback() can be used by an embedder to register its own
> unhandled exception handler for exceptions that arise in v8-generated code.
> V8 embedders should be modified accordingly (code for this is in a separate PR
> in the Chromium repository:
> https://chromium-review.googlesource.com/c/chromium/src/+/1474703).
> 
> All these changes are experimental, behind:
> 
> the 'v8_win64_unwinding_info' build flag, and
> the '--win64-unwinding-info' runtime flag.
> 
> Bug: v8:3598
> Change-Id: Iea455ab6d0e2bf1c556aa1cf870841d44ab6e4b1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1469329
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Paolo Severini <paolosev@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#60330}

Bug: v8:3598
Change-Id: If988baf7d3e4af165b919d6e54c1ad985f8e25e3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1534618
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Paolo Severini <paolosev@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#60581}
2019-04-03 02:00:43 +00:00
Leszek Swirski
9f6ddb48a0 Revert "V8 x64 backend doesn't emit ABI compliant stack frames"
This reverts commit 3cda21de77.

Reason for revert: Breaks the roll on Windows (see https://cr-buildbucket.appspot.com/build/8918477701097622400)

Original change's description:
> V8 x64 backend doesn't emit ABI compliant stack frames
> 
> On 64 bit Windows, the OS stack walking does not work because the V8 x64
> backend doesn't emit unwinding info and also because it doesn't emit ABI
> compliant stack frames. See
> https://docs.google.com/document/d/1-wf50jFlii0c_Pr52lm2ZU-49m220nhYMrHDi3vXnh0/edit
> for more details.
> 
> This problem can be fixed by observing that V8 frames usually all have the same
> prolog and epilog:
> 
> push rbp,
> mov rbp, rsp
> ...
> pop rbp
> ret N
> 
> and that it is possible to define XDATA (UNWIND_CODEs) that specify how Windows
> should walk through V8 frames. Furthermore, since V8 Code objects are all
> allocated in the same code-range for an Isolate, it is possible to register a
> single PDATA/XDATA entry to cover stack walking for all the code generated
> inside that code-range.
> 
> This PR contains changes required to enable stack walking on Win64:
> 
> EmbeddedFileWriter now adds assembler directives to the builtins
> snapshot source file (embedded.cc) to emit additional entries in the .pdata and
> in the .xdata section of the V8 executable. This takes care of stack walking
> for embedded builtins. (The case of non-embedded builtins is not supported).
> The x64 Assembler has been modified to collect the information required to emit
> this unwind info for builtins.
> 
> Stack walking for jitted code is handled is Isolate.cpp, by registering
> dynamically PDATA/XDATA for the whole code-range address space every time a new
> Isolate is initialized, and by unregistering them when the Isolate is
> destroyed.
> 
> Stack walking for WASM jitted code is handled is the same way in
> wasm::NativeModule (wasm/wasm-code-manager.cpp).
> 
> It is important to note that Crashpad and Breakpad are already registering
> PDATA/XDATA to manage and report unhandled exceptions (but not for embedded
> builtins). Since it is not possible to register multiple PDATA entries for the
> same address range, a new function is added to the V8 API:
> SetUnhandledExceptionCallback() can be used by an embedder to register its own
> unhandled exception handler for exceptions that arise in v8-generated code.
> V8 embedders should be modified accordingly (code for this is in a separate PR
> in the Chromium repository:
> https://chromium-review.googlesource.com/c/chromium/src/+/1474703).
> 
> All these changes are experimental, behind:
> 
> the 'v8_win64_unwinding_info' build flag, and
> the '--win64-unwinding-info' runtime flag.
> 
> Bug: v8:3598
> Change-Id: Iea455ab6d0e2bf1c556aa1cf870841d44ab6e4b1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1469329
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Paolo Severini <paolosev@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#60330}

TBR=bbudge@chromium.org,ulan@chromium.org,mvstanton@chromium.org,mstarzinger@chromium.org,gdeepti@chromium.org,jgruber@chromium.org,paolosev@microsoft.com

Change-Id: If8470da94c58df8c800cbe8887f9f86236e43353
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:3598
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1532321
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60372}
2019-03-20 14:36:04 +00:00
Paolo Severini
3cda21de77 V8 x64 backend doesn't emit ABI compliant stack frames
On 64 bit Windows, the OS stack walking does not work because the V8 x64
backend doesn't emit unwinding info and also because it doesn't emit ABI
compliant stack frames. See
https://docs.google.com/document/d/1-wf50jFlii0c_Pr52lm2ZU-49m220nhYMrHDi3vXnh0/edit
for more details.

This problem can be fixed by observing that V8 frames usually all have the same
prolog and epilog:

push rbp,
mov rbp, rsp
...
pop rbp
ret N

and that it is possible to define XDATA (UNWIND_CODEs) that specify how Windows
should walk through V8 frames. Furthermore, since V8 Code objects are all
allocated in the same code-range for an Isolate, it is possible to register a
single PDATA/XDATA entry to cover stack walking for all the code generated
inside that code-range.

This PR contains changes required to enable stack walking on Win64:

EmbeddedFileWriter now adds assembler directives to the builtins
snapshot source file (embedded.cc) to emit additional entries in the .pdata and
in the .xdata section of the V8 executable. This takes care of stack walking
for embedded builtins. (The case of non-embedded builtins is not supported).
The x64 Assembler has been modified to collect the information required to emit
this unwind info for builtins.

Stack walking for jitted code is handled is Isolate.cpp, by registering
dynamically PDATA/XDATA for the whole code-range address space every time a new
Isolate is initialized, and by unregistering them when the Isolate is
destroyed.

Stack walking for WASM jitted code is handled is the same way in
wasm::NativeModule (wasm/wasm-code-manager.cpp).

It is important to note that Crashpad and Breakpad are already registering
PDATA/XDATA to manage and report unhandled exceptions (but not for embedded
builtins). Since it is not possible to register multiple PDATA entries for the
same address range, a new function is added to the V8 API:
SetUnhandledExceptionCallback() can be used by an embedder to register its own
unhandled exception handler for exceptions that arise in v8-generated code.
V8 embedders should be modified accordingly (code for this is in a separate PR
in the Chromium repository:
https://chromium-review.googlesource.com/c/chromium/src/+/1474703).

All these changes are experimental, behind:

the 'v8_win64_unwinding_info' build flag, and
the '--win64-unwinding-info' runtime flag.

Bug: v8:3598
Change-Id: Iea455ab6d0e2bf1c556aa1cf870841d44ab6e4b1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1469329
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Paolo Severini <paolosev@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#60330}
2019-03-19 14:36:17 +00:00