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bmeurer authored
Revert of [wasm] Initial signal handler (patchset #56 id:1090001 of https://codereview.chromium.org/2371833007/ ) Reason for revert: Breaks tree, i.e. https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20ASAN/builds/18928/steps/Check/logs/grow-memory Original issue's description: > [wasm] Initial signal handler > > This is basically the minimum viable signal handler for Wasm bounds checks. > It includes the TLS check and the fine grained instructions checks. These > two checks provide most of the safety for the signal handler. Future CLs will > add code range and data range checks for more robustness. > > The trap handling code and data structures are all in src/trap-handler, with > the code that actually runs in the signal handler confined to > src/trap-handler/signal-handler.cc. > > This changes adds a new V8 API that the embedder should call from a signal > handler that will give V8 the chance to handle the fault first. For hosts that > do not want to implement their own signal handler, we include the option to > install a simple one. This simple handler is also used for the tests. > > When a Wasm module is instantiated, information about each function is passed > to the trap handler, which is used to classify faults. These are removed during > the instance finalizer. > > Several future enhancements are planned before turning this on by default. > Obviously, the additional checks will be added to MaybeHandleFault. We are > also planning to add a two-level CodeObjectData table that is grouped by > isolates to make cleanup easier and also reduce potential for contending on > a single data structure. > > BUG= https://bugs.chromium.org/p/v8/issues/detail?id=5277 > > Review-Url: https://codereview.chromium.org/2371833007 > Cr-Commit-Position: refs/heads/master@{#43523} > Committed: https://chromium.googlesource.com/v8/v8/+/a5af7fe9ee388a636675f4a6872b1d34fa7d1a7a TBR=ahaas@chromium.org,bradnelson@google.com,hpayer@chromium.org,jochen@chromium.org,mark@chromium.org,mseaborn@chromium.org,titzer@chromium.org,eholk@chromium.org # Skipping CQ checks because original CL landed less than 1 days ago. NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true BUG= https://bugs.chromium.org/p/v8/issues/detail?id=5277 Review-Url: https://codereview.chromium.org/2723133003 Cr-Commit-Position: refs/heads/master@{#43525}
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