Re: [PATCH bpf 1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register spilling
From: Andrii Nakryiko <hidden>
Date: 2021-01-12 19:47:50
Also in:
bpf, lkml
On Tue, Jan 12, 2021 at 1:14 AM Gilad Reti [off-list ref] wrote:
Add support for pointer to mem register spilling, to allow the verifier
to track pointer to valid memory addresses. Such pointers are returned
for example by a successful call of the bpf_ringbuf_reserve helper.
This patch was suggested as a solution by Yonghong Song.
The patch was partially contibuted by CyberArk Software, Inc.
Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier
support for it")Surprised no one mentioned this yet. Fixes tag should always be on a single unwrapped line, however long it is, please fix.
quoted hunk ↗ jump to hunk
Signed-off-by: Gilad Reti <redacted> --- 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