bpf, tests: Add test for 32-bit context pointer argument passing

On a 32-bit architecture, the context pointer will occupy the low
half of R1, and the other half will be zero.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210809091829.810076-12-johan.almbladh@anyfinetworks.com

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 896d37f..fcfaf45 100644 (file)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -2092,6 +2092,22 @@ static struct bpf_test tests[] = {
 #undef NUMER
 #undef DENOM
        },
+#ifdef CONFIG_32BIT
+       {
+               "INT: 32-bit context pointer word order and zero-extension",
+               .u.insns_int = {
+                       BPF_ALU32_IMM(BPF_MOV, R0, 0),
+                       BPF_JMP32_IMM(BPF_JEQ, R1, 0, 3),
+                       BPF_ALU64_IMM(BPF_RSH, R1, 32),
+                       BPF_JMP32_IMM(BPF_JNE, R1, 0, 1),
+                       BPF_ALU32_IMM(BPF_MOV, R0, 1),
+                       BPF_EXIT_INSN(),
+               },
+               INTERNAL,
+               { },
+               { { 0, 1 } }
+       },
+#endif
        {
                "check: missing ret",
                .u.insns = {