diff mbox series

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

Message ID 20210113053810.13518-1-gilad.reti@gmail.com (mailing list archive)
State Accepted
Commit 744ea4e3885eccb6d332a06fae9eb7420a622c0f
Headers show
Series [bpf,v2,1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register spilling | expand

Commit Message

Gilad Reti Jan. 13, 2021, 5:38 a.m. UTC
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>
---
 kernel/bpf/verifier.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

KP Singh Jan. 13, 2021, 10:29 p.m. UTC | #1
On Wed, Jan 13, 2021 at 6:38 AM Gilad Reti <gilad.reti@gmail.com> wrote:
>
> 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>

Acked-by: KP Singh <kpsingh@kernel.org>
Alexei Starovoitov Jan. 14, 2021, 4:02 a.m. UTC | #2
On Wed, Jan 13, 2021 at 2:29 PM KP Singh <kpsingh@kernel.org> wrote:
>
> On Wed, Jan 13, 2021 at 6:38 AM Gilad Reti <gilad.reti@gmail.com> wrote:
> >
> > 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>
>
> Acked-by: KP Singh <kpsingh@kernel.org>

It's a border line feature vs fix.
Since the patch is trivial and it addresses a real problem I've
applied to the bpf tree.
Thanks!
diff mbox series

Patch

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;