[PATCH bpf v2 1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register spilling

[Gilad Reti]

Add support for pointer to mem register spilling, to allow the verifier
to track pointers to valid memory addresses. Such pointers are returned
for example by a successful call of the bpf_ringbuf_reserve helper.

The patch was partially contributed by CyberArk Software, Inc.

Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for 
it")
Suggested-by: Yonghong Song <y...@fb.com>
Signed-off-by: Gilad Reti <gilad.r...@gmail.com>
---
 kernel/bpf/verifier.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 17270b8404f1..36af69fac591 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2217,6 +2217,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
        case PTR_TO_RDWR_BUF:
        case PTR_TO_RDWR_BUF_OR_NULL:
        case PTR_TO_PERCPU_BTF_ID:
+       case PTR_TO_MEM:
+       case PTR_TO_MEM_OR_NULL:
                return true;
        default:
                return false;
-- 
2.27.0