Messages in this thread | | | From | Andrey Konovalov <> | Date | Mon, 18 Mar 2019 17:08:48 +0100 | Subject | Re: [PATCH v11 08/14] net, arm64: untag user pointers in tcp_zerocopy_receive |
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On Mon, Mar 18, 2019 at 3:45 PM Eric Dumazet <edumazet@google.com> wrote: > > On Mon, Mar 18, 2019 at 6:17 AM Andrey Konovalov <andreyknvl@google.com> wrote: > > > > > Looking at the code, what's the point of this address != zc->address > > check? Should I just remove it? > > No you must not remove it. > > The test detects if a u64 ->unsigned long conversion might have truncated bits. > > Quite surprisingly some people still use 32bit kernels. > > The ABI is 64bit only, because we did not want to have yet another compat layer. > > struct tcp_zerocopy_receive { > __u64 address; /* in: address of mapping */ > __u32 length; /* in/out: number of bytes to map/mapped */ > __u32 recv_skip_hint; /* out: amount of bytes to skip */ > };
Ah, got it, thanks! I'll add a comment here then, otherwise this looks confusing.
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