On Sunday 19 August 2007, Anton Altaparmakov wrote: > > > > ISTR we don't *have* a uintptr_t on all architectures, or that would > > be the appropriate thing to use in these 32/64 bit ABI scenarios. > > > > > >> Use unsigned long or uintptr_t instead. > > > > I suspect you mean "unsigned long long"... > > No he doesn't. "unsigned long" is guaranteed to be large enough to > hold a pointer (at least on Linux anyway).
And yet when I used that, I got compiler warnings on some systems. ISTR that was the first solution I tried, but GCC really wanted to issue warnings. Either about casting 64-bit to pointer, or about casting it to "unsigned long", either way lost precision. > On a 32-bit arch "unsigned long" is 32-bit and pointers are 32-bit. > > On a 64-bit archi "unsigned long" is 64-bit and pointers are 64-bit. So with 32 bit userspace "unsigned long long" is the type to use when talking to a 64-bit kernel; and with pure 64-bit code, it's enough to write "unsigned long". I'm fairly sure that's the root cause of the pain I recall here; but I'd have to run experiments again to verify that. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/