/*
* syscall enter notification (analysis function)
*
* save the system call context and invoke the pre-syscall callback
* function (if registered)
*
* @tid: thread id
* @ctx: CPU context
* @std: syscall standard (e.g., Linux IA-32, IA-64, etc)
* @v: callback value
*/
static void
sysenter_save(THREADID tid, CONTEXT *ctx, SYSCALL_STANDARD std, VOID *v)
{
/* get the thread context */
thread_ctx_t *thread_ctx = (thread_ctx_t *)
PIN_GetContextReg(ctx, thread_ctx_ptr);
/* get the syscall number */
size_t syscall_nr = PIN_GetSyscallNumber(ctx, std);
/* unknown syscall; optimized branch */
if (unlikely(syscall_nr >= SYSCALL_MAX)) {
LOG(string(__func__) + ": unknown syscall (num=" +
decstr(syscall_nr) + ")\n");
/* syscall number is set to -1; hint for the sysexit_save() */
thread_ctx->syscall_ctx.nr = -1;
/* no context save and no pre-syscall callback invocation */
return;
}
/* pass the system call number to sysexit_save() */
thread_ctx->syscall_ctx.nr = syscall_nr;
/*
* check if we need to save the arguments for that syscall
*
* we save only when we have a callback registered or the syscall
* returns a value in the arguments
*/
if (syscall_desc[syscall_nr].save_args |
syscall_desc[syscall_nr].retval_args) {
/*
* dump only the appropriate number of arguments
* or yet another lame way to avoid a loop (vpk)
*/
switch (syscall_desc[syscall_nr].nargs) {
/* 6 */
case SYSCALL_ARG5 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG5] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG5);
/* 5 */
case SYSCALL_ARG4 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG4] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG4);
/* 4 */
case SYSCALL_ARG3 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG3] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG3);
/* 3 */
case SYSCALL_ARG2 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG2] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG2);
/* 2 */
case SYSCALL_ARG1 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG1] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG1);
/* 1 */
case SYSCALL_ARG0 + 1:
thread_ctx->syscall_ctx.arg[SYSCALL_ARG0] =
PIN_GetSyscallArgument(ctx,
std,
SYSCALL_ARG0);
/* default */
default:
/* nothing to do */
break;
}
/*
* dump the architectural state of the processor;
* saved as "auxiliary" data
*/
thread_ctx->syscall_ctx.aux = ctx;
/* call the pre-syscall callback (if any) */
if (syscall_desc[syscall_nr].pre != NULL)
syscall_desc[syscall_nr].pre(&thread_ctx->syscall_ctx);
}
}
int whiteList_init(struct whiteList* list, const char* file_name){
FILE* file = NULL;
long size;
int i;
int n;
list->buffer = NULL;
if ((file = fopen(file_name, "rb")) == NULL){
LOG("ERROR: unable to open file: ");
LOG(file_name);
LOG("\n");
goto error;
}
if (fseek(file, 0, SEEK_END)){
LOG("ERROR: unable to fseek\n");
goto error;
}
size = ftell(file);
rewind(file);
if ((list->buffer = (char*)malloc(size + 1)) == NULL){
LOG("ERROR: unable to allocate memory\n");
goto error;
}
if (fread(list->buffer, 1, size, file) != (size_t)size){
LOG("ERROR: unable to read file\n");
goto error;
}
fclose(file);
file = NULL;
list->buffer[size] = '\0';
for (i = size; i > 0; ){
i --;
if (list->buffer[i] == '\0' || list->buffer[i] == '\n'){
list->buffer[i] = '\0';
}
else{
break;
}
}
for (i = 0, list->nb_entry = 1; i < size; i++){
if (list->buffer[i] == '\n'){
list->nb_entry ++;
list->buffer[i] = '\0';
}
}
if ((list->entries = (char**)malloc(sizeof(char*)*list->nb_entry)) == NULL){
LOG("ERROR: unable to allocate memory\n");
goto error;
}
list->entries[0] = list->buffer;
for (n = 1, i = 0; n < list->nb_entry; n++){
while ((i < size) && (list->buffer[i] != '\0')){
i++;
}
if (i >= size){
LOG("ERROR: searching for end of line fails at line " + decstr(n) + ":" + decstr(list->nb_entry) + "\n");
list->entries[n] = list->entries[n-1];
}
else{
i++;
list->entries[n] = list->buffer + i;
}
}
qsort(list->entries, list->nb_entry, sizeof(char*), whiteList_compare);
return 0;
error:
if (file != NULL){
fclose(file);
}
if (list->buffer != NULL){
free(list->buffer);
}
return -1;
}
void post_write_hook(syscall_ctx_t *ctx) {
/* ignore write() on not watched fd */
if (unlikely(fdset.find(_FD) == fdset.end()))
return;
/* write() was not successful; optimized branch; errno message may be incorrect */
if (unlikely(_N_WRITTEN < 0)) {
LOG("ERROR " _CALL_LOG_STR + " (" + strerror(errno) + ")\n");
return;
}
LOG("OK " _CALL_LOG_STR + "\n");
const ufd_t ufd = ufdmap.get(_FD);
off_t write_begin;
range_map_t ranges;
range_map_t ranges_prev;
/* calculate begining of write */
if (IS_STDFD(_FD)) {
write_begin = stdcount[_FD];
stdcount[_FD] += _N_WRITTEN;
}
else {
write_begin = lseek(_FD, 0, SEEK_CUR) - _N_WRITTEN;
if ( unlikely(write_begin < 0) ){
LOG("Error on L" + decstr(__LINE__) + " lseek-ing on fd" + decstr(_FD) + ": " + strerror(errno) + "\n");
return;
}
}
for(ssize_t i=0; i<_N_WRITTEN; i++) { //loop through memory locations
tag_t tag = tagmap_getb(_BUF+i);
#ifdef __DEBUG_SYSCALL_WRITE
LOG("---------------------- " + std::string((char *)(_BUF+i), 1) + "\n");
LOG("RANGES " + __RANGE2STR(ranges) + "\n");
LOG("RANGES_PREV " + __RANGE2STR(ranges_prev) + "\n");
#endif
for (auto & tm : tag) { //loop taint marks for specific location
// check if a single taint mark from the input is repeated in the output
auto rlookup = tm;
auto range_it = ranges_prev.find(rlookup);
if (range_it != ranges_prev.end()) {
// LOG("C1\n");
auto range_last = (*range_it).first;
auto range_info = (*range_it).second;
switch(range_info.type) {
case range_info_t::SEQ:
// adjust SEQ range
range_last.second--;
range_info.length--;
ranges_prev.insert(range_it, std::make_pair(range_last, range_info));
ranges_prev.erase(range_it);
// add a new REP range to next range set
ranges.insert(std::make_pair(tm, (range_info_t){range_info_t::REP, i-1, 2}));
continue;
case range_info_t::NONE:
// set range type to REP
range_info.type = range_info_t::REP;
case range_info_t::REP:
// add info to next range set
range_info.length++;
ranges.insert(std::make_pair(tm, range_info));
// remove info from previous range set
ranges_prev.erase(range_it);
continue;
}
}
// check if a sequence of taint marks from the input also appears in the output
rlookup = tm;
rlookup.second -= 1;
range_it = ranges_prev.find(rlookup);
if (range_it != ranges_prev.end()) {
// LOG("C2\n");
auto range_info = (*range_it).second;
switch(range_info.type) {
case range_info_t::REP:
// start a new range - we won't touch the old one
ranges.insert(std::make_pair(tm, (range_info_t){range_info_t::NONE, i, 1}));
continue;
case range_info_t::NONE:
// set range type to SEQ
range_info.type = range_info_t::SEQ;
case range_info_t::SEQ:
// add info to next range set
range_info.length++;
ranges.insert(std::make_pair(tm, range_info));
// remove info from previous range set
ranges_prev.erase(range_it);
continue;
}
}
// add taint mark as a new range
// LOG("C3\n");
rlookup = tm;
ranges.insert(std::make_pair(rlookup, (range_info_t){range_info_t::NONE, i, 1}));
} //loop taint marks
#ifdef __DEBUG_SYSCALL_WRITE
LOG("~~~~~~~~~~~~~~\n");
LOG("RANGES " + __RANGE2STR(ranges) + "\n");
LOG("RANGES_PREV " + __RANGE2STR(ranges_prev) + "\n");
#endif
//dump output for pattern sequences that were broken
for (auto &tm : ranges_prev)
PROVLOG_WRITE_RANGE(ufd, write_begin, tm.first, tm.second);
// swap the two range sets and clear the ranges for next iteration
ranges.swap(ranges_prev);
ranges.clear();
} //loop memory locations
//dump the remaining pattern sequences
for (auto &tm : ranges_prev)
PROVLOG_WRITE_RANGE(ufd, write_begin, tm.first, tm.second);
}
VOID trace_instrument(TRACE trace, VOID *v){
for (BBL bbl = TRACE_BblHead(trace); BBL_Valid(bbl); bbl = BBL_Next(bbl)){
/* iterate over all basic blocks */
string codelet_string = "";
// this writes disassembly
char codelet_buffer[65536*2]; int cbs = 0;
INS head = BBL_InsHead(bbl);
INS tail = BBL_InsTail(bbl);
ADDRINT stage_entry = INS_Address( head );
ADDRINT target = 0;
if (INS_IsCall(tail)){
if( INS_IsDirectBranchOrCall(tail)){
target = INS_DirectBranchOrCallTargetAddress(tail);}}
INS cur ;
int branch_id = slp_count;
/* If compression is turned off (default), only output the addresses of
* the BBL once
*/
if (!KnobNoCompress){
/* Instrument the head instruction right before it is called, but also
* before we instrument the instructions in the basic block
*/
string msg_pre = "\n@@BBL(" + decstr( branch_id ) + ") STAGE " + Target2String(stage_entry)->c_str() + "\n" ;
INS_InsertCall(head, IPOINT_BEFORE, AFUNPTR(string_report),
IARG_PTR, new string(msg_pre),
IARG_END);
}
/* Walk the list of instructions inside the BBL. Disassemble each, and add
* it to the codelet string. Also, instrument each instruction at the
* point before it is called with the do_count function.
*/
for ( cur = head; INS_Valid( cur ); cur = INS_Next(cur ) ){
cbs += sprintf( codelet_buffer + cbs , "\n\t@%llx\t%s", INS_Address( cur ), INS_Disassemble( cur ).c_str() );
INS_InsertCall(cur, IPOINT_BEFORE, (AFUNPTR)do_count, IARG_ADDRINT, INS_Address( cur ), IARG_END);
}
/* Finish off the codelet assembly string with an out message and
* address ranges of the BBL
*/
cbs += sprintf( codelet_buffer + cbs , "\n\t}BBL.OUT [%d] %llx - %llx\n", branch_id, INS_Address( head ), INS_Address( tail ));
/* If compression is turned on, output the codelet every single time we
* hit the same block.
*/
if(KnobNoCompress){
INS_InsertCall(tail, IPOINT_BEFORE, AFUNPTR(string_report),
IARG_PTR, new string(codelet_buffer),
IARG_END);
slp_count ++;
}
else{
/* add the mapped BBL to output */
TraceFile.write(codelet_buffer, cbs);
/* Instrument the tail instruction by inserting just before it is called
*/
string msg_post = "+@@BBL(" + decstr( branch_id ) + ") ACHIEVE : GOTO " + Target2String(target)->c_str();
INS_InsertCall(tail, IPOINT_BEFORE, AFUNPTR(string_report),
IARG_PTR, new string(msg_post),
IARG_END);
slp_count ++;
}
}
}
string nocrypt(u_char* nocipher)
{
string decstr(reinterpret_cast<const char*>(nocipher));
return decstr;
}