diff mbox series

[net-next,07/13] nfp: bpf: relax source operands check

Message ID 20171201053300.17503-8-jakub.kicinski@netronome.com
State Accepted, archived
Delegated to: BPF Maintainers
Headers show
Series nfp: bpf: jump resolution and memcpy update | expand

Commit Message

Jakub Kicinski Dec. 1, 2017, 5:32 a.m. UTC 
From: Jiong Wang <jiong.wang@netronome.com>

The NFP normally requires the source operands to be difference addressing
modes, but we should rule out the very special NN_REG_NONE type.

There are instruction that ignores both A/B operands, for example:

  local_csr_rd

For these instructions, we might pass the same operand type, NN_REG_NONE,
for both A/B operands.

NOTE: in current NFP ISA, it is only possible for instructions with
unrestricted operands to take none operands, but in case there is new and
similar instructoin in restricted form, they would follow similar rules,
so swreg_to_restricted is updated as well.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_asm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
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Patch

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.c b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
index 830f6de25f47..da277386077c 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
@@ -120,7 +120,8 @@  int swreg_to_unrestricted(swreg dst, swreg lreg, swreg rreg,
 	reg->dst = nfp_swreg_to_unreg(dst, true);
 
 	/* Decode source operands */
-	if (swreg_type(lreg) == swreg_type(rreg))
+	if (swreg_type(lreg) == swreg_type(rreg) &&
+	    swreg_type(lreg) != NN_REG_NONE)
 		return -EFAULT;
 
 	if (swreg_type(lreg) == NN_REG_GPR_B ||
@@ -200,7 +201,8 @@  int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg,
 	reg->dst = nfp_swreg_to_rereg(dst, true, false, NULL);
 
 	/* Decode source operands */
-	if (swreg_type(lreg) == swreg_type(rreg))
+	if (swreg_type(lreg) == swreg_type(rreg) &&
+	    swreg_type(lreg) != NN_REG_NONE)
 		return -EFAULT;
 
 	if (swreg_type(lreg) == NN_REG_GPR_B ||