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| author | Alexei Starovoitov <ast@kernel.org> | 2019-11-14 21:57:19 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-11-16 01:45:50 +0300 |
| commit | 4c0963243c5f56bffe8eaba6acc5b076d51797f4 (patch) | |
| tree | dcf2b3e9e78fc78843bb1c0b28287309049feb4d | |
| parent | e7bf94dbb882b7d679a6a18e40e4f28076eb249f (diff) | |
| download | linux-4c0963243c5f56bffe8eaba6acc5b076d51797f4.tar.xz | |
selftests/bpf: Extend test_pkt_access test
The test_pkt_access.o is used by multiple tests. Fix its section name so that
program type can be automatically detected by libbpf and make it call other
subprograms with skb argument.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-20-ast@kernel.org
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_pkt_access.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_pkt_access.c b/tools/testing/selftests/bpf/progs/test_pkt_access.c index 7cf42d14103f..3a7b4b607ed3 100644 --- a/tools/testing/selftests/bpf/progs/test_pkt_access.c +++ b/tools/testing/selftests/bpf/progs/test_pkt_access.c @@ -17,8 +17,38 @@ #define barrier() __asm__ __volatile__("": : :"memory") int _version SEC("version") = 1; -SEC("test1") -int process(struct __sk_buff *skb) +/* llvm will optimize both subprograms into exactly the same BPF assembly + * + * Disassembly of section .text: + * + * 0000000000000000 test_pkt_access_subprog1: + * ; return skb->len * 2; + * 0: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0) + * 1: 64 00 00 00 01 00 00 00 w0 <<= 1 + * 2: 95 00 00 00 00 00 00 00 exit + * + * 0000000000000018 test_pkt_access_subprog2: + * ; return skb->len * val; + * 3: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0) + * 4: 64 00 00 00 01 00 00 00 w0 <<= 1 + * 5: 95 00 00 00 00 00 00 00 exit + * + * Which makes it an interesting test for BTF-enabled verifier. + */ +static __attribute__ ((noinline)) +int test_pkt_access_subprog1(volatile struct __sk_buff *skb) +{ + return skb->len * 2; +} + +static __attribute__ ((noinline)) +int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb) +{ + return skb->len * val; +} + +SEC("classifier/test_pkt_access") +int test_pkt_access(struct __sk_buff *skb) { void *data_end = (void *)(long)skb->data_end; void *data = (void *)(long)skb->data; @@ -48,6 +78,10 @@ int process(struct __sk_buff *skb) tcp = (struct tcphdr *)((void *)(ip6h) + ihl_len); } + if (test_pkt_access_subprog1(skb) != skb->len * 2) + return TC_ACT_SHOT; + if (test_pkt_access_subprog2(2, skb) != skb->len * 2) + return TC_ACT_SHOT; if (tcp) { if (((void *)(tcp) + 20) > data_end || proto != 6) return TC_ACT_SHOT; |