mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-08-07 15:39:27 -04:00
a0cb12b031
We are relying on the fact, that we can pass > sizeof(int) optvals to the SOL_IP+IP_FREEBIND option (the kernel will take first 4 bytes). In the BPF program we check that we can only touch PAGE_SIZE bytes, but the real optlen is PAGE_SIZE * 2. In both cases, we override it to some predefined value and trim the optlen. Also, let's modify exiting IP_TOS usecase to test optlen=0 case where BPF program just bypasses the data as is. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200617010416.93086-2-sdf@google.com
================== BPF Selftest Notes ================== General instructions on running selftests can be found in `Documentation/bpf/bpf_devel_QA.rst`_. Additional information about selftest failures are documented here. bpf_iter test failures with clang/llvm 10.0.0 ============================================= With clang/llvm 10.0.0, the following two bpf_iter tests failed: * ``bpf_iter/ipv6_route`` * ``bpf_iter/netlink`` The symptom for ``bpf_iter/ipv6_route`` looks like .. code-block:: c 2: (79) r8 = *(u64 *)(r1 +8) ... 14: (bf) r2 = r8 15: (0f) r2 += r1 ; BPF_SEQ_PRINTF(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 16: (7b) *(u64 *)(r8 +64) = r2 only read is supported The symptom for ``bpf_iter/netlink`` looks like .. code-block:: c ; struct netlink_sock *nlk = ctx->sk; 2: (79) r7 = *(u64 *)(r1 +8) ... 15: (bf) r2 = r7 16: (0f) r2 += r1 ; BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_protocol); 17: (7b) *(u64 *)(r7 +0) = r2 only read is supported This is due to a llvm BPF backend bug. The fix https://reviews.llvm.org/D78466 has been pushed to llvm 10.x release branch and will be available in 10.0.1. The fix is available in llvm 11.0.0 trunk.