Re: [PATCH] hcidump: add support for time64 based libc

[Arnd Bergmann]

On Fri, Jan 10, 2020 at 10:05 PM Rich Felker <dalias@xxxxxxxx> wrote:
>
> On Fri, Jan 10, 2020 at 09:49:03PM +0100, Arnd Bergmann wrote:
> > musl is moving to a default of 64-bit time_t on all architectures,
> > glibc will follow later. This breaks reading timestamps through cmsg
> > data with the HCI_TIME_STAMP socket option.
> >
> > Change both copies of hcidump to work on all architectures.  This also
> > fixes x32, which has never worked, and carefully avoids breaking sparc64,
> > which is another special case.
>
> Won't it be broken on rv32 though? Based on my (albeit perhaps
> incomplete) reading of the thread, I think use of HCI_TIME_STAMP
> should just be dropped entirely in favor of using SO_TIMESTAMPNS -- my
> understanding was that it works with bluetooth sockets too.

All 32-bit architectures use old_timeval32 timestamps in the kernel
here, even rv32 and x32. As a rule, we keep the types bug-for-bug
compatible between architectures and fix them all at the same time.

Changing hcidump to SO_TIMESTAMPNS would work as well, but
that is a much bigger change and I don't know how to test that.

     Arnd