void *hwasan_pvalloc(uptr size, StackTrace *stack) {
uptr PageSize = GetPageSizeCached();
if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
errno = errno_ENOMEM;
if (AllocatorMayReturnNull())
return nullptr;
ReportPvallocOverflow(size, stack);
}
// pvalloc(0) should allocate one page.
size = size ? RoundUpTo(size, PageSize) : PageSize;
return SetErrnoOnNull(HwasanAllocate(stack, size, PageSize, false));
}
// If this is a shadow fault, we handle it here; otherwise, we pass it to the
// app to handle it just as the app would do without our tool in place.
static void handleMemoryFault(int SigNum, __sanitizer_siginfo *Info,
void *Ctx) {
if (SigNum == SIGSEGV) {
// We rely on si_addr being filled in (thus we do not support old kernels).
siginfo_t *SigInfo = (siginfo_t *)Info;
uptr Addr = (uptr)SigInfo->si_addr;
if (isShadowMem(Addr)) {
VPrintf(3, "Shadow fault @%p\n", Addr);
uptr PageSize = GetPageSizeCached();
int Res = internal_mprotect((void *)RoundDownTo(Addr, PageSize),
PageSize, PROT_READ|PROT_WRITE);
CHECK(Res == 0);
} else if (AppSigAct.sigaction) {
// FIXME: For simplicity we ignore app options including its signal stack
// (we just use ours) and all the delivery flags.
AppSigAct.sigaction(SigNum, Info, Ctx);
} else {
// Crash instead of spinning with infinite faults.
reinstateDefaultHandler(SigNum);
}
} else
UNREACHABLE("signal not registered");
}
void *hwasan_valloc(uptr size, StackTrace *stack) {
return SetErrnoOnNull(
HwasanAllocate(stack, size, GetPageSizeCached(), false));
}
