bpf: add various verifier test cases for self-tests

Add a couple of test cases, for example, probing for xadd on a spilled
pointer to packet and map_value_adj register, various other map_value_adj
tests including the unaligned load/store, and trying out pointer arithmetic
on map_value_adj register itself. For the unaligned load/store, we need
to figure out whether the architecture has efficient unaligned access and
need to mark affected tests accordingly.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 0 deletions

diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h
index 122153b16ea4..390d7c9685fd 100644
--- a/tools/include/linux/filter.h
+++ b/tools/include/linux/filter.h
@@ -168,6 +168,16 @@
                 .off   = OFF,                                   \
                 .imm   = 0 })
 
+/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
+
+#define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
+        ((struct bpf_insn) {                                    \
+                .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
+                .dst_reg = DST,                                 \
+                .src_reg = SRC,                                 \
+                .off   = OFF,                                   \
+                .imm   = 0 })
+
 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 
 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \