From f6f2332dce0efeea8c5653b6e9d1e8c379ace65c Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@plumgrid.com>
Date: Tue, 16 Sep 2014 18:32:58 -0700
Subject: [PATCH] sparc: bpf_jit: fix support for ldx/stx mem and
 SKF_AD_VLAN_TAG

fix several issues in sparc BPF JIT compiler.

ldx/stx related:
. classic BPF instructions that access mem[] slots were not setting
  SEEN_MEM flag, so stack wasn't allocated. Fix that by advertising
  correct flags

. LDX/STX instructions were missing SEEN_XREG, so register value
  could have leaked to user space. Fix it.

. since stack for mem[] slots is allocated with 'sub %sp' instead
  of 'save %sp', use %sp as base register instead of %fp.

. ldx mem[0] means first slot in classic BPF which should have
  -4 offset instead of 0.

. sparc64 needs 2047 stack bias as per ABI to access stack

. emit_stmem() was using LD32I macro instead of ST32I

SKF_AD_VLAN_TAG* related:
. SKF_AD_VLAN_TAG_PRESENT must return 1 or 0 instead of '> 0' or 0
  as per classic BPF de facto standard

. SKF_AD_VLAN_TAG needs to mask the field correctly

Fixes: 2809a2087cc4 ("net: filter: Just In Time compiler for sparc")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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