lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20170503074820.23c79a62@redhat.com> Date: Wed, 3 May 2017 07:48:20 +0200 From: Jesper Dangaard Brouer <brouer@...hat.com> To: Alexei Starovoitov <alexei.starovoitov@...il.com> Cc: kafai@...com, netdev@...r.kernel.org, eric@...it.org, Daniel Borkmann <borkmann@...earbox.net>, brouer@...hat.com Subject: Re: [net-next PATCH 2/4] samples/bpf: make bpf_load.c code compatible with ELF maps section changes On Tue, 2 May 2017 17:54:51 -0700 Alexei Starovoitov <alexei.starovoitov@...il.com> wrote: > On Tue, May 02, 2017 at 02:31:56PM +0200, Jesper Dangaard Brouer wrote: > > This patch does proper parsing of the ELF "maps" section, in-order to > > be both backwards and forwards compatible with changes to the map > > definition struct bpf_map_def, which gets compiled into the ELF file. > > > > The assumption is that new features with value zero, means that they > > are not in-use. For backward compatibility where loading an ELF file > > with a smaller struct bpf_map_def, only copy objects ELF size, leaving > > rest of loaders struct zero. For forward compatibility where ELF file > > have a larger struct bpf_map_def, only copy loaders own struct size > > and verify that rest of the larger struct is zero, assuming this means > > the newer feature was not activated, thus it should be safe for this > > older loader to load this newer ELF file. > > > > Fixes: fb30d4b71214 ("bpf: Add tests for map-in-map") > > Fixes: 409526bea3c3 ("samples/bpf: bpf_load.c detect and abort if ELF maps section size is wrong") > > Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com> > > I would just merge patches 2 and 3 to reduce churn, > but it looks like great improvement already. I could have combined them, but I prefer keeping them separate to keep the ELF changes separated from changing a sample program e.g. map_perf_test_user.c. IHMO is is cleaner this way. > Acked-by: Alexei Starovoitov <ast@...nel.org> Thanks -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
Powered by blists - more mailing lists