Re: [bpf PATCH v2 3/5] bpf, selftests: Add tests for ctx access in sock_ops with single register
From: Song Liu <song@kernel.org>
Date: 2020-07-29 21:36:16
Also in:
bpf
On Wed, Jul 29, 2020 at 9:24 AM John Fastabend [off-list ref] wrote:
[...]
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <redacted>
quoted hunk ↗ jump to hunk
--- .../testing/selftests/bpf/progs/test_tcpbpf_kern.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)diff --git a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c index 1f1966e..f8b13682 100644 --- a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c +++ b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c@@ -54,6 +54,7 @@ SEC("sockops") int bpf_testcb(struct bpf_sock_ops *skops) { char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)]; + struct bpf_sock_ops *reuse = skops; struct tcphdr *thdr; int good_call_rv = 0; int bad_call_rv = 0;@@ -62,6 +63,18 @@ int bpf_testcb(struct bpf_sock_ops *skops) int v = 0; int op; + /* Test reading fields in bpf_sock_ops using single register */ + asm volatile ( + "%[reuse] = *(u32 *)(%[reuse] +96)" + : [reuse] "+r"(reuse) + :); + + asm volatile ( + "%[op] = *(u32 *)(%[skops] +96)" + : [op] "+r"(op) + : [skops] "r"(skops) + :); +
Shall we add a separate test for this? It does seem to fix in bpf_testcb().
op = (int) skops->op;
update_event_map(op);