35627cf37f
* Implement wasm trap handlers. This adds signal handlers based on SpiderMonkey's signal-handler code. The functionality for looking up the trap code and wasm bytecode offset isn't yet implemented, but this is a start. I considered rewriting this code in Rust, but decided against it for now as C++ allows us to talk to the relevant OS APIs more directly. Fixes #15. * Compile with -std=c++11. * Refactor InstallState initialization. * Compile with -fPIC. * Factor out the code for calling a wasm function with a given index. * Fix unclear wording in a comment.
56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
#ifndef signal_handlers_h
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#define signal_handlers_h
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#include <stdint.h>
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#include <setjmp.h>
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#ifndef __cplusplus
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#include <stdbool.h>
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#endif
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#ifdef __cplusplus
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extern "C" {
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#endif
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struct CodeSegment;
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// Record the Trap code and wasm bytecode offset in TLS somewhere
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void RecordTrap(const uint8_t* pc, const struct CodeSegment* codeSegment);
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// Initiate an unwind.
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void Unwind(void);
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// Return the CodeSegment containing the given pc, if any exist in the process.
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// This method does not take a lock.
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const struct CodeSegment*
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LookupCodeSegment(const void* pc);
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// Trap initialization state.
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struct TrapContext {
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bool triedToInstallSignalHandlers;
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bool haveSignalHandlers;
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};
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// This function performs the low-overhead signal handler initialization that we
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// want to do eagerly to ensure a more-deterministic global process state. This
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// is especially relevant for signal handlers since handler ordering depends on
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// installation order: the wasm signal handler must run *before* the other crash
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// handlers and since POSIX signal handlers work LIFO, this function needs to be
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// called at the end of the startup process, after other handlers have been
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// installed. This function can thus be called multiple times, having no effect
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// after the first call.
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bool
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EnsureEagerSignalHandlers(void);
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// Assuming EnsureEagerProcessSignalHandlers() has already been called,
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// this function performs the full installation of signal handlers which must
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// be performed per-thread. This operation may incur some overhead and
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// so should be done only when needed to use wasm.
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bool
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EnsureDarwinMachPorts(struct TrapContext* cx);
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#endif // signal_handlers_h
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