On Jan 10, 2020, at 1:19 PM, Arnd Bergmann arnd@arndb.de wrote:
On Fri, Jan 10, 2020 at 10:05 PM Rich Felker dalias@libc.org 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.
If so, maybe I'll just do that for libpcap. Libpcap *does* have an API to request capturing with nanoseconds in tv_usec (and I plan to give it pcapng-flavored APIs to deliver higher-resolution time stamps, as well as metadata such as "incoming" vs. "outgoing", as well).