hack some stuff towards running on mac... unrelated bugs still..
[c11tester.git] / snapshot.cc
index cdc2528da14a7a1204b5fd9011a3aaf4c07784e7..e3ca558878d2a811bb1f639e6234e2c475023326 100644 (file)
@@ -4,7 +4,6 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <map>
-#include <set>
 #include <cstring>
 #include <cstdio>
 #include "snapshot.h"
@@ -19,8 +18,8 @@
 #include <ucontext.h>
 
 //extern declaration definition
-#define FAILURE(mesg) { printf("failed in the API: %s with errno relative message: %s\n", mesg, strerror( errno ) ); exit( -1 ); }
-#if USE_CHECKPOINTING
+#define FAILURE(mesg) { printf("failed in the API: %s with errno relative message: %s\n", mesg, strerror( errno ) ); exit(EXIT_FAILURE); }
+#if USE_MPROTECT_SNAPSHOT
 struct SnapShot * snapshotrecord = NULL;
 struct Snapshot_t * sTheRecord = NULL;
 #else
@@ -38,13 +37,13 @@ void DumpIntoLog( const char * filename, const char * message ){
        myFile = NULL;
 #endif
 }
-#if !USE_CHECKPOINTING
+#if !USE_MPROTECT_SNAPSHOT
 static ucontext_t savedSnapshotContext;
 static ucontext_t savedUserSnapshotContext;
-static int snapshotid = 0;
+static snapshot_id snapshotid = 0;
 #endif
 /* Initialize snapshot data structure */
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
 void initSnapShotRecord(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions) {
        snapshotrecord=( struct SnapShot * )MYMALLOC(sizeof(struct SnapShot));
        snapshotrecord->regionsToSnapShot=( struct MemoryRegion * )MYMALLOC(sizeof(struct MemoryRegion)*nummemoryregions);
@@ -63,7 +62,7 @@ void initSnapShotRecord(unsigned int numbackingpages, unsigned int numsnapshots,
 #endif //nothing to initialize for the fork based snapshotting.
 
 void HandlePF( int sig, siginfo_t *si, void * unused){
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        if( si->si_code == SEGV_MAPERR ){
                printf("Real Fault at %p\n", si->si_addr);
                exit( EXIT_FAILURE );
@@ -102,7 +101,7 @@ void * PageAlignAddressUpward(void * addr) {
 extern "C" {
 #endif
        void createSharedLibrary(){
-#if !USE_CHECKPOINTING
+#if !USE_MPROTECT_SNAPSHOT
                //step 1. create shared memory.
                if( sTheRecord ) return;
                int fd = shm_open( "/ModelChecker-Snapshotter", O_RDWR | O_CREAT, 0777 ); //universal permissions.
@@ -116,13 +115,16 @@ extern "C" {
                sTheRecord->mStackSize = STACK_SIZE_DEFAULT;
                sTheRecord->mIDToRollback = -1;
                sTheRecord->currSnapShotID = 0;
+               sTheRecord->mbFinalize = false;
 #endif
        }
 #ifdef __cplusplus
 }
 #endif
-void initSnapShotLibrary(unsigned int numbackingpages, unsigned int numsnapshots, unsigned int nummemoryregions, unsigned int numheappages, MyFuncPtr entryPoint){
-#if USE_CHECKPOINTING
+void initSnapShotLibrary(unsigned int numbackingpages,
+               unsigned int numsnapshots, unsigned int nummemoryregions,
+               unsigned int numheappages, VoidFuncPtr entryPoint) {
+#if USE_MPROTECT_SNAPSHOT
        /* Setup a stack for our signal handler....  */
        stack_t ss;
        ss.ss_sp = MYMALLOC(SIGSTACKSIZE);
@@ -134,27 +136,38 @@ void initSnapShotLibrary(unsigned int numbackingpages, unsigned int numsnapshots
        sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART | SA_ONSTACK;
        sigemptyset( &sa.sa_mask );
        sa.sa_sigaction = HandlePF;
+#ifdef MAC
+       if( sigaction( SIGBUS, &sa, NULL ) == -1 ){
+               printf("SIGACTION CANNOT BE INSTALLED\n");
+               exit(EXIT_FAILURE);
+       }
+#endif
        if( sigaction( SIGSEGV, &sa, NULL ) == -1 ){
                printf("SIGACTION CANNOT BE INSTALLED\n");
-               exit(-1);
+               exit(EXIT_FAILURE);
        }
+
        initSnapShotRecord(numbackingpages, numsnapshots, nummemoryregions);
 
+       // EVIL HACK: We need to make sure that calls into the HandlePF method don't cause dynamic links
+       // The problem is that we end up protecting state in the dynamic linker...
+       // Solution is to call our signal handler before we start protecting stuff...
+
+       siginfo_t si;
+       si.si_addr=ss.ss_sp;
+       HandlePF(SIGSEGV, &si, NULL);
+       snapshotrecord->lastBackingPage--; //remove the fake page we copied
+
        basemySpace=MYMALLOC((numheappages+1)*PAGESIZE);
        void * pagealignedbase=PageAlignAddressUpward(basemySpace);
        mySpace = create_mspace_with_base(pagealignedbase,  numheappages*PAGESIZE, 1 );
        addMemoryRegionToSnapShot(pagealignedbase, numheappages);
        entryPoint();
 #else
-       //add a signal to indicate that the process is going to terminate.
-       struct sigaction sa;
-       sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART;
-       sigemptyset( &sa.sa_mask );
-       sa.sa_sigaction = HandlePF;
-       if( sigaction( SIGUSR1, &sa, NULL ) == -1 ){
-               printf("SIGACTION CANNOT BE INSTALLED\n");
-               exit(-1);
-       }
+
+       basemySpace=system_malloc((numheappages+1)*PAGESIZE);
+       void * pagealignedbase=PageAlignAddressUpward(basemySpace);
+       mySpace = create_mspace_with_base(pagealignedbase,  numheappages*PAGESIZE, 1 );
        createSharedLibrary();
 
        //step 2 setup the stack context.
@@ -204,7 +217,7 @@ void initSnapShotLibrary(unsigned int numbackingpages, unsigned int numsnapshots
                        } while( -1 == retVal && errno == EINTR );
 
                        if( sTheRecord->mIDToRollback != snapshotid )
-                               exit(0);
+                               exit(EXIT_SUCCESS);
                        else{
                                swapContext = true;
                        }
@@ -215,11 +228,11 @@ void initSnapShotLibrary(unsigned int numbackingpages, unsigned int numsnapshots
 }
 /* This function assumes that addr is page aligned */
 void addMemoryRegionToSnapShot( void * addr, unsigned int numPages) {
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        unsigned int memoryregion=snapshotrecord->lastRegion++;
        if (memoryregion==snapshotrecord->maxRegions) {
                printf("Exceeded supported number of memory regions!\n");
-               exit(-1);
+               exit(EXIT_FAILURE);
        }
 
        snapshotrecord->regionsToSnapShot[ memoryregion ].basePtr=addr;
@@ -228,18 +241,18 @@ void addMemoryRegionToSnapShot( void * addr, unsigned int numPages) {
 }
 //take snapshot
 snapshot_id takeSnapshot( ){
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
                if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ ) == -1 ){
                        perror("mprotect");
                        printf("Failed to mprotect inside of takeSnapShot\n");
-                       exit(-1);
+                       exit(EXIT_FAILURE);
                }
        }
        unsigned int snapshot=snapshotrecord->lastSnapShot++;
        if (snapshot==snapshotrecord->maxSnapShots) {
                printf("Out of snapshots\n");
-               exit(-1);
+               exit(EXIT_FAILURE);
        }
        snapshotrecord->snapShots[snapshot].firstBackingPage=snapshotrecord->lastBackingPage;
 
@@ -250,13 +263,13 @@ snapshot_id takeSnapshot( ){
 #endif
 }
 void rollBack( snapshot_id theID ){
-#if USE_CHECKPOINTING
+#if USE_MPROTECT_SNAPSHOT
        std::map< void *, bool, std::less< void * >, MyAlloc< std::pair< const void *, bool > > > duplicateMap;
        for(unsigned int region=0; region<snapshotrecord->lastRegion;region++) {
                if( mprotect(snapshotrecord->regionsToSnapShot[region].basePtr, snapshotrecord->regionsToSnapShot[region].sizeInPages*sizeof(struct SnapShotPage), PROT_READ | PROT_WRITE ) == -1 ){
                        perror("mprotect");
                        printf("Failed to mprotect inside of takeSnapShot\n");
-                       exit(-1);
+                       exit(EXIT_FAILURE);
                }
        }
        for(unsigned int page=snapshotrecord->snapShots[theID].firstBackingPage; page<snapshotrecord->lastBackingPage; page++) {
@@ -283,13 +296,13 @@ void rollBack( snapshot_id theID ){
 #if SSDEBUG
                DumpIntoLog( "ModelSnapshot", "Invoked rollback" );
 #endif
-               exit( 0 );
+               exit(EXIT_SUCCESS);
        }
 #endif
 }
 
 void finalize(){
-#if !USE_CHECKPOINTING
+#if !USE_MPROTECT_SNAPSHOT
        sTheRecord->mbFinalize = true;
 #endif
 }