https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64435
--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
PPC64 actually supports both 44 and 46 bit address space:
uptr GetMaxVirtualAddress() {
#if SANITIZER_WORDSIZE == 64
# if defined(__powerpc64__)
// On PowerPC64 we have two different address space layouts: 44- and 46-bit.
// We somehow need to figure out which one we are using now and choose
// one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
// Note that with 'ulimit -s unlimited' the stack is moved away from the top
// of the address space, so simply checking the stack address is not enough.
// This should (does) work for both PowerPC64 Endian modes.
return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
# elif defined(__aarch64__)
return (1ULL << 39) - 1;
# elif defined(__mips64)
return (1ULL << 40) - 1;
# else
return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
# endif
#else // SANITIZER_WORDSIZE == 32
uptr res = (1ULL << 32) - 1; // 0xffffffff;
if (!common_flags()->full_address_space)
res -= GetKernelAreaSize();
CHECK_LT(reinterpret_cast<uptr>(&res), res);
return res;
#endif // SANITIZER_WORDSIZE
}
it is just that aarch64 hardcodes this right now. Suppose doing something like
ppc64 does could work.
