From b3c7cb7c151858ef79f9371a29be49915e5d3803 Mon Sep 17 00:00:00 2001 From: James Turner Date: Tue, 15 Apr 2014 14:13:46 +0100 Subject: [PATCH] Fix crash with Nasal bindings. naBindFunction doesn't save the function code to the global hash, so pass an explicit context to various 'call' overloads so the function can't be GC-ed in between parsing and calling. (Patch by Nicholas Scheel) https://code.google.com/p/flightgear-bugs/issues/detail?id=1397 --- src/Scripting/NasalSys.cxx | 53 ++++++++++++++++++++++++-------------- src/Scripting/NasalSys.hxx | 4 ++- 2 files changed, 37 insertions(+), 20 deletions(-) diff --git a/src/Scripting/NasalSys.cxx b/src/Scripting/NasalSys.cxx index ae5cbe59f..6e8c4ef05 100644 --- a/src/Scripting/NasalSys.cxx +++ b/src/Scripting/NasalSys.cxx @@ -236,6 +236,11 @@ naRef FGNasalSys::call(naRef code, int argc, naRef* args, naRef locals) return callMethod(code, naNil(), argc, args, locals); } +naRef FGNasalSys::callWithContext(naContext ctx, naRef code, int argc, naRef* args, naRef locals) +{ + return callMethodWithContext(ctx, code, naNil(), argc, args, locals); +} + // Does a naCall() in a new context. Wrapped here to make lock // tracking easier. Extension functions are called with the lock, but // we have to release it before making a new naCall(). So rather than @@ -248,6 +253,11 @@ naRef FGNasalSys::callMethod(naRef code, naRef self, int argc, naRef* args, naRe return naCallMethod(code, self, argc, args, locals); } +naRef FGNasalSys::callMethodWithContext(naContext ctx, naRef code, naRef self, int argc, naRef* args, naRef locals) +{ + return naCallMethodCtx(ctx, code, self, argc, args, locals); +} + FGNasalSys::~FGNasalSys() { if (_inited) { @@ -258,11 +268,15 @@ FGNasalSys::~FGNasalSys() bool FGNasalSys::parseAndRun(const char* sourceCode) { - naRef code = parse("FGNasalSys::parseAndRun()", sourceCode, + naContext ctx = naNewContext(); + naRef code = parse(ctx, "FGNasalSys::parseAndRun()", sourceCode, strlen(sourceCode)); - if(naIsNil(code)) + if(naIsNil(code)) { + naFreeContext(ctx); return false; - call(code, 0, 0, naNil()); + } + callWithContext(ctx, code, 0, 0, naNil()); + naFreeContext(ctx); return true; } @@ -1072,11 +1086,13 @@ bool FGNasalSys::createModule(const char* moduleName, const char* fileName, const SGPropertyNode* cmdarg, int argc, naRef* args) { - naRef code = parse(fileName, src, len); - if(naIsNil(code)) - return false; - naContext ctx = naNewContext(); + naRef code = parse(ctx, fileName, src, len); + if(naIsNil(code)) { + naFreeContext(ctx); + return false; + } + // See if we already have a module hash to use. This allows the // user to, for example, add functions to the built-in math @@ -1089,7 +1105,7 @@ bool FGNasalSys::createModule(const char* moduleName, const char* fileName, _cmdArg = (SGPropertyNode*)cmdarg; - call(code, argc, args, locals); + callWithContext(ctx, code, argc, args, locals); hashset(_globals, moduleName, locals); naFreeContext(ctx); @@ -1111,10 +1127,9 @@ void FGNasalSys::deleteModule(const char* moduleName) naFreeContext(ctx); } -naRef FGNasalSys::parse(const char* filename, const char* buf, int len) +naRef FGNasalSys::parse(naContext ctx, const char* filename, const char* buf, int len) { int errLine = -1; - naContext ctx = naNewContext(); naRef srcfile = naNewString(ctx); naStr_fromdata(srcfile, (char*)filename, strlen(filename)); naRef code = naParseCode(ctx, srcfile, 1, (char*)buf, len, &errLine); @@ -1122,14 +1137,11 @@ naRef FGNasalSys::parse(const char* filename, const char* buf, int len) SG_LOG(SG_NASAL, SG_ALERT, "Nasal parse error: " << naGetError(ctx) << " in "<< filename <<", line " << errLine); - naFreeContext(ctx); return naNil(); } // Bind to the global namespace before returning - naRef bound = naBindFunction(ctx, code, _globals); - naFreeContext(ctx); - return bound; + return naBindFunction(ctx, code, _globals); } bool FGNasalSys::handleCommand( const char* moduleName, @@ -1137,22 +1149,24 @@ bool FGNasalSys::handleCommand( const char* moduleName, const char* src, const SGPropertyNode* arg ) { - naRef code = parse(fileName, src, strlen(src)); - if(naIsNil(code)) return false; + naContext ctx = naNewContext(); + naRef code = parse(ctx, fileName, src, strlen(src)); + if(naIsNil(code)) { + naFreeContext(ctx); + return false; + } // Commands can be run "in" a module. Make sure that module // exists, and set it up as the local variables hash for the // command. naRef locals = naNil(); if(moduleName[0]) { - naContext ctx = naNewContext(); naRef modname = naNewString(ctx); naStr_fromdata(modname, (char*)moduleName, strlen(moduleName)); if(!naHash_get(_globals, modname, &locals)) { locals = naNewHash(ctx); naHash_set(_globals, modname, locals); } - naFreeContext(ctx); } // Cache this command's argument for inspection via cmdarg(). For @@ -1160,7 +1174,8 @@ bool FGNasalSys::handleCommand( const char* moduleName, // code doesn't need it. _cmdArg = (SGPropertyNode*)arg; - call(code, 0, 0, locals); + callWithContext(ctx, code, 0, 0, locals); + naFreeContext(ctx); return true; } diff --git a/src/Scripting/NasalSys.hxx b/src/Scripting/NasalSys.hxx index 8915c38bf..44f30b5bd 100644 --- a/src/Scripting/NasalSys.hxx +++ b/src/Scripting/NasalSys.hxx @@ -102,8 +102,10 @@ public: void globalsSet(const char* key, naRef val); naRef call(naRef code, int argc, naRef* args, naRef locals); + naRef callWithContext(naContext ctx, naRef code, int argc, naRef* args, naRef locals); naRef callMethod(naRef code, naRef self, int argc, naRef* args, naRef locals); + naRef callMethodWithContext(naContext ctx, naRef code, naRef self, int argc, naRef* args, naRef locals); naRef propNodeGhost(SGPropertyNode* handle); @@ -169,7 +171,7 @@ private: void loadScriptDirectory(simgear::Dir nasalDir); void addModule(std::string moduleName, simgear::PathList scripts); static void logError(naContext); - naRef parse(const char* filename, const char* buf, int len); + naRef parse(naContext ctx, const char* filename, const char* buf, int len); naRef genPropsModule(); bool _inited;