selftests/bpf: Test narrow loads with off > 0 in test_verifier

Test the following narrow loads in test_verifier for context __sk_buff:
* off=1, size=1 - ok;
* off=2, size=1 - ok;
* off=3, size=1 - ok;
* off=0, size=2 - ok;
* off=1, size=2 - fail;
* off=0, size=2 - ok;
* off=3, size=2 - fail.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 6f61df62f690c69adceb2c328b231ab39b8b9c49..54d16fbdef8b931037928e89890710f70333f45e 100644 (file)
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -2026,29 +2026,27 @@ static struct bpf_test tests[] = {
                .result = ACCEPT,
        },
        {
-               "check skb->hash byte load not permitted 1",
+               "check skb->hash byte load permitted 1",
                .insns = {
                        BPF_MOV64_IMM(BPF_REG_0, 0),
                        BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
                                    offsetof(struct __sk_buff, hash) + 1),
                        BPF_EXIT_INSN(),
                },
-               .errstr = "invalid bpf_context access",
-               .result = REJECT,
+               .result = ACCEPT,
        },
        {
-               "check skb->hash byte load not permitted 2",
+               "check skb->hash byte load permitted 2",
                .insns = {
                        BPF_MOV64_IMM(BPF_REG_0, 0),
                        BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
                                    offsetof(struct __sk_buff, hash) + 2),
                        BPF_EXIT_INSN(),
                },
-               .errstr = "invalid bpf_context access",
-               .result = REJECT,
+               .result = ACCEPT,
        },
        {
-               "check skb->hash byte load not permitted 3",
+               "check skb->hash byte load permitted 3",
                .insns = {
                        BPF_MOV64_IMM(BPF_REG_0, 0),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -2060,8 +2058,7 @@ static struct bpf_test tests[] = {
 #endif
                        BPF_EXIT_INSN(),
                },
-               .errstr = "invalid bpf_context access",
-               .result = REJECT,
+               .result = ACCEPT,
        },
        {
                "check cb access: byte, wrong type",
@@ -2173,7 +2170,7 @@ static struct bpf_test tests[] = {
                .result = ACCEPT,
        },
        {
-               "check skb->hash half load not permitted",
+               "check skb->hash half load permitted 2",
                .insns = {
                        BPF_MOV64_IMM(BPF_REG_0, 0),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -2182,6 +2179,37 @@ static struct bpf_test tests[] = {
 #else
                        BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
                                    offsetof(struct __sk_buff, hash)),
+#endif
+                       BPF_EXIT_INSN(),
+               },
+               .result = ACCEPT,
+       },
+       {
+               "check skb->hash half load not permitted, unaligned 1",
+               .insns = {
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+                       BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
+                                   offsetof(struct __sk_buff, hash) + 1),
+#else
+                       BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
+                                   offsetof(struct __sk_buff, hash) + 3),
+#endif
+                       BPF_EXIT_INSN(),
+               },
+               .errstr = "invalid bpf_context access",
+               .result = REJECT,
+       },
+       {
+               "check skb->hash half load not permitted, unaligned 3",
+               .insns = {
+                       BPF_MOV64_IMM(BPF_REG_0, 0),
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+                       BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
+                                   offsetof(struct __sk_buff, hash) + 3),
+#else
+                       BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
+                                   offsetof(struct __sk_buff, hash) + 1),
 #endif
                        BPF_EXIT_INSN(),
                },