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  1. 03 Apr, 2019 1 commit
    • Paolo Severini's avatar
      Reland "V8 x64 backend doesn't emit ABI compliant stack frames" · 969cb0c7
      Paolo Severini authored 
      This is a reland of 3cda21de

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/+/1534618Reviewed-by: 's avatarJakob Gruber <jgruber@chromium.org>
Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Paolo Severini <paolosev@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#60581}
      969cb0c7
  3. 02 Apr, 2019 19 commits
  5. 01 Apr, 2019 20 commits