[PATCH bpf-next] nfp: bpf: allow source ptr type be map ptr in memcpy optimization

[PATCH bpf-next] nfp: bpf: allow source ptr type be map ptr in memcpy optimization

[Jakub Kicinski]

From: Jiong Wang <jiong.wang@netronome.com>

Map read has been supported on NFP, this patch enables optimization
for memcpy from map to packet.

This patch also fixed one latent bug which will cause copying from
unexpected address once memcpy for map pointer enabled.  The fixed
code path was not exercised before.

Reported-by: Mary Pham <mary.pham@netronome.com>
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
---
Reposting separately from the mul/div patches.

 drivers/net/ethernet/netronome/nfp/bpf/jit.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index 8a92088df0d7..33111739b210 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -670,7 +670,7 @@ static int nfp_cpp_memcpy(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 	xfer_num = round_up(len, 4) / 4;
 
 	if (src_40bit_addr)
-		addr40_offset(nfp_prog, meta->insn.src_reg, off, &src_base,
+		addr40_offset(nfp_prog, meta->insn.src_reg * 2, off, &src_base,
 			      &off);
 
 	/* Setup PREV_ALU fields to override memory read length. */
@@ -3299,7 +3299,8 @@ curr_pair_is_memcpy(struct nfp_insn_meta *ld_meta,
 	if (!is_mbpf_load(ld_meta) || !is_mbpf_store(st_meta))
 		return false;
 
-	if (ld_meta->ptr.type != PTR_TO_PACKET)
+	if (ld_meta->ptr.type != PTR_TO_PACKET &&
+	    ld_meta->ptr.type != PTR_TO_MAP_VALUE)
 		return false;
 
 	if (st_meta->ptr.type != PTR_TO_PACKET)
-- 
2.17.1

Re: [PATCH bpf-next] nfp: bpf: allow source ptr type be map ptr in memcpy optimization

[Daniel Borkmann]

On 06/27/2018 04:48 AM, Jakub Kicinski wrote:
> From: Jiong Wang <jiong.wang@netronome.com>
> 
> Map read has been supported on NFP, this patch enables optimization
> for memcpy from map to packet.
> 
> This patch also fixed one latent bug which will cause copying from
> unexpected address once memcpy for map pointer enabled.  The fixed
> code path was not exercised before.
> 
> Reported-by: Mary Pham <mary.pham@netronome.com>
> Reported-by: David Beckett <david.beckett@netronome.com>
> Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
> Acked-by: Song Liu <songliubraving@fb.com>

Applied to bpf-next, thanks guys!