Dean Scarff <d...@scarff.id.au> writes: > On Mon, 02 Nov 2020 13:37:00 +0100, Toke wrote: >> Dean Scarff <d...@scarff.id.au> writes: >> >>> Hi, >>> >>> I've been happily running the out-of-tree sch_cake on my Raspberry >>> Pi >>> since 2015. However, I recently upgraded my kernel (to 5.4.72 from >>> Raspbian's raspberrypi-kernel 1.20201022-1), which comes with the >>> sch_cake in mainline. Now, when running: >>> >>> sudo /sbin/tc qdisc add dev ppp0 root cake >>> >>> I get the error: >>> >>> Error: NLA_F_NESTED is missing. >>> >>> I get this error with the sch_cake in mainline, and also with >>> sch_cake >>> built out-of-tree. I also get the error with both Debian's >>> iproute2 >>> 5.9.0-1 (built myself via debian/rules) and "tc" from dtaht's >>> tc-adv >>> repo. >>> >>> Any ideas on what this error means and how to fix it? >> >> I just tried building a 5.4.72 kernel and couldn't reproduce this, so >> it >> seems it's a fault with the raspberry pi kernel; I guess opening a >> bug >> against that would be the way to go? >> >> As for what's actually causing this, I couldn't find anything obvious >> that touches this code in the qdisc layer; but I suppose it has >> something to do with the core qdisc netlink parsing code? >> >> -Toke > > Thanks for the data point. > > For the record, the relevant kernel source is: > > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/include/net/netlink.h?h=v5.4.72#n1143 > and the Pi branch: > > https://github.com/raspberrypi/linux/blob/raspberrypi-kernel_1.20201022-1/include/net/netlink.h#L1143 > > It seems very unlikely that the Pi folks are patching the netlink > stuff, so I don't think I'll get much traction there unless I can call > out something specifically wrong with their patchset.
Well, something odd is certainly going on. The error message you're quoting comes form a part of the netlink parsing code (in the kernel) that shouldn't even be hit by the qdisc addition: NLA_F_NESTED parsing is only enabled in 'strict' validation mode, which is not used for qdiscs. So IDK, maybe a compiler issue or a bit that gets set wrong somewhere? Bisecting the kernel may be the only option here, I don't think you're going to find anything in userspace... -Toke _______________________________________________ Cake mailing list Cake@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cake