void NCValidateSegment(uint8_t *mbase, NaClPcAddress vbase, size_t sz,
struct NCValidatorState *vstate) {
if (sz == 0) {
ValidatePrintError(0, "Bad text segment (zero size)", vstate);
Stats_SegFault(vstate);
return;
}
GetCPUFeatures(&(vstate->cpufeatures));
/* The name of the flag is misleading; f_386 requires not just */
/* 386 instructions but also the CPUID instruction is supported. */
if (!vstate->cpufeatures.f_386) {
ValidatePrintError(0, "CPU does not support CPUID", vstate);
Stats_BadCPU(vstate);
return;
}
#if (0)
/* TODO(bradchen): enable this check */
if (!vstate->cpufeatures.f_whitelisted) {
ValidatePrintError(0, "CPU does not support CPUID", vstate);
Stats_BadCPU(vstate);
return;
}
#endif
NCDecodeSegment(mbase, vbase, sz, vstate);
}
static void BadInstructionError(const struct NCDecoderState *mstate,
const char *msg) {
ValidatePrintError(mstate->inst.vaddr, msg, mstate->vstate);
if (mstate->vstate->do_stub_out) {
memset(mstate->inst.maddr, kNaClFullStop, mstate->inst.length);
}
}
static void ValidateCallAlignment(const struct NCDecoderState *mstate) {
NaClPcAddress fallthru = mstate->inst.vaddr + mstate->inst.length;
if (fallthru & mstate->vstate->alignmask) {
ValidatePrintError(mstate->inst.vaddr, "Bad call alignment",
mstate->vstate);
/* This makes bad call alignment a fatal error. */
Stats_BadAlignment(mstate->vstate);
}
}
static void ForgetIP(const NaClPcAddress ip,
struct NCValidatorState *vstate) {
NaClMemorySize ioffset = ip - vstate->iadrbase;
if (ip < vstate->iadrbase || ip >= vstate->iadrlimit) {
ValidatePrintError(ip, "JUMP TARGET out of range in ForgetIP", vstate);
Stats_BadTarget(vstate);
return;
}
ClearAdrTable(ioffset, vstate->vttable);
}
int NCValidateFinish(struct NCValidatorState *vstate) {
uint32_t offset;
if (vstate == NULL) {
vprint(("validator not initialized. Did you call ncvalidate_init()?\n"));
/* non-zero indicates failure */
return 1;
}
dprint(("CheckTargets: %x-%x\n", vstate->iadrbase, vstate->iadrlimit));
for (offset = 0;
offset < vstate->iadrlimit - vstate->iadrbase;
offset += 1) {
if (GetAdrTable(offset, vstate->kttable)) {
/* printf("CheckTarget %x\n", offset + iadrbase); */
Stats_CheckTarget(vstate);
if (!GetAdrTable(offset, vstate->vttable)) {
ValidatePrintError(vstate->iadrbase + offset,
"Bad jump target", vstate);
Stats_BadTarget(vstate);
}
}
}
/* check basic block boundaries */
if (vstate->iadrbase & vstate->alignmask) {
/* This should never happen because the alignment of iadrbase is */
/* checked in NCValidateInit(). */
ValidatePrintError(vstate->iadrbase, "Bad base address alignment", vstate);
Stats_BadAlignment(vstate);
}
for (offset = 0; offset < vstate->iadrlimit - vstate->iadrbase;
offset += vstate->alignment) {
if (!GetAdrTable(offset, vstate->vttable)) {
ValidatePrintError(vstate->iadrbase + offset,
"Bad basic block alignment", vstate);
Stats_BadAlignment(vstate);
}
}
fflush(stdout);
/* Now that all the work is done, generate return code. */
/* Return zero if there are no problems. */
return (vstate->stats.sawfailure);
}
/*
* (Same as NCValidateSegment, but operates on a pair of instructions.)
* Validates that instructions at mbase_new may replace mbase_old.
*/
void NCValidateSegmentPair(uint8_t *mbase_old, uint8_t *mbase_new,
NaClPcAddress vbase, size_t sz,
struct NCValidatorState *vstate) {
if (sz == 0) {
ValidatePrintError(0, "Bad text segment (zero size)", vstate);
Stats_SegFault(vstate);
return;
}
GetCPUFeatures(&(vstate->cpufeatures));
/* The name of the flag is misleading; f_386 requires not just */
/* 386 instructions but also the CPUID instruction is supported. */
if (!vstate->cpufeatures.f_386) {
ValidatePrintError(0, "CPU does not support CPUID", vstate);
Stats_BadCPU(vstate);
return;
}
NCDecodeSegmentPair(mbase_old, mbase_new, vbase, sz,
vstate, ValidateInstReplacement);
}
static void RememberTP(const NaClPcAddress src, NaClPcAddress target,
struct NCValidatorState *vstate) {
const NaClMemorySize ioffset = target - vstate->iadrbase;
if (vstate->iadrbase <= target && target < vstate->iadrlimit) {
/* Remember address for checking later. */
SetAdrTable(ioffset, vstate->kttable);
}
else if ((target & vstate->alignmask) == 0) {
/* Allow bundle-aligned jumps. */
}
else {
ValidatePrintError(src, "JUMP TARGET out of range", vstate);
Stats_BadTarget(vstate);
}
}
static void RememberIP(const NaClPcAddress ip,
struct NCValidatorState *vstate) {
const NaClMemorySize ioffset = ip - vstate->iadrbase;
if (ip < vstate->iadrbase || ip >= vstate->iadrlimit) {
ValidatePrintError(ip, "JUMP TARGET out of range in RememberIP", vstate);
Stats_BadTarget(vstate);
return;
}
if (GetAdrTable(ioffset, vstate->vttable)) {
vprint(("RememberIP: Saw inst at %"NACL_PRIxNaClPcAddressAll
" twice\n", ip));
Stats_InternalError(vstate);
return;
}
Stats_Inst(vstate);
SetAdrTable(ioffset, vstate->vttable);
}
static void ValidatePrintOffsetError(const NaClPcAddress addr,
const char *msg,
struct NCValidatorState *vstate) {
ValidatePrintError(vstate->iadrbase + addr, msg, vstate);
}
static void ValidatePrintInstructionError(const struct NCDecoderInst *dinst,
const char *msg,
struct NCValidatorState *vstate) {
ValidatePrintError(NCPrintableInstructionAddress(dinst), msg, vstate);
}