From: Gilad Reti gilad.reti@gmail.com
commit 744ea4e3885eccb6d332a06fae9eb7420a622c0f upstream.
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 yhs@fb.com Signed-off-by: Gilad Reti gilad.reti@gmail.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: KP Singh kpsingh@kernel.org Link: https://lore.kernel.org/bpf/20210113053810.13518-1-gilad.reti@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/bpf/verifier.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2214,6 +2214,8 @@ static bool is_spillable_regtype(enum bp 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;