From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu, 12 Oct 2017 10:34:16 -0700
Subject: nfp: bpf: add support for direct packet access - read
Patch-mainline: v4.15-rc1
Git-commit: 2ca71441f524b0a0cc01d8e51c875b00fbe31275
References: bsc#1109837
In direct packet access bound checks are already done, we can
simply dereference the packet pointer.
Verifier/parser logic needs to record pointer type. Note that
although verifier does protect us from CTX vs other pointer
changes we will also want to differentiate between PACKET vs
MAP_VALUE or STACK, so we can add the check already.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 85 ++++++++++++++++++++--
drivers/net/ethernet/netronome/nfp/bpf/main.h | 3
drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 21 +++--
drivers/net/ethernet/netronome/nfp/nfp_asm.c | 3
drivers/net/ethernet/netronome/nfp/nfp_asm.h | 4 +
5 files changed, 105 insertions(+), 11 deletions(-)
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -544,6 +544,36 @@ data_ld(struct nfp_prog *nfp_prog, swreg
}
static int
+data_ld_host_order(struct nfp_prog *nfp_prog, u8 src_gpr, swreg offset,
+ u8 dst_gpr, int size)
+{
+ unsigned int i;
+ u8 mask, sz;
+
+ /* We load the value from the address indicated in @offset and then
+ * mask out the data we don't need. Note: this is little endian!
+ */
+ sz = max(size, 4);
+ mask = size < 4 ? GENMASK(size - 1, 0) : 0;
+
+ emit_cmd(nfp_prog, CMD_TGT_READ32_SWAP, CMD_MODE_32b, 0,
+ reg_a(src_gpr), offset, sz / 4 - 1, true);
+
+ i = 0;
+ if (mask)
+ emit_ld_field_any(nfp_prog, reg_both(dst_gpr), mask,
+ reg_xfer(0), SHF_SC_NONE, 0, true);
+ else
+ for (; i * 4 < size; i++)
+ wrp_mov(nfp_prog, reg_both(dst_gpr + i), reg_xfer(i));
+
+ if (i < 2)
+ wrp_immed(nfp_prog, reg_both(dst_gpr + 1), 0);
+
+ return 0;
+}
+
+static int
construct_data_ind_ld(struct nfp_prog *nfp_prog, u16 offset, u16 src, u8 size)
{
swreg tmp_reg;
@@ -1117,12 +1147,53 @@ static int mem_ldx_xdp(struct nfp_prog *
return 0;
}
+static int
+mem_ldx_data(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ unsigned int size)
+{
+ swreg tmp_reg;
+
+ tmp_reg = re_load_imm_any(nfp_prog, meta->insn.off, imm_b(nfp_prog));
+
+ return data_ld_host_order(nfp_prog, meta->insn.src_reg * 2, tmp_reg,
+ meta->insn.dst_reg * 2, size);
+}
+
+static int
+mem_ldx(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ unsigned int size)
+{
+ if (meta->ptr.type == PTR_TO_CTX) {
+ if (nfp_prog->act == NN_ACT_XDP)
+ return mem_ldx_xdp(nfp_prog, meta, size);
+ else
+ return mem_ldx_skb(nfp_prog, meta, size);
+ }
+
+ if (meta->ptr.type == PTR_TO_PACKET)
+ return mem_ldx_data(nfp_prog, meta, size);
+
+ return -EOPNOTSUPP;
+}
+
+static int mem_ldx1(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ return mem_ldx(nfp_prog, meta, 1);
+}
+
+static int mem_ldx2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ return mem_ldx(nfp_prog, meta, 2);
+}
+
static int mem_ldx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- if (nfp_prog->act == NN_ACT_XDP)
- return mem_ldx_xdp(nfp_prog, meta, 4);
- else
- return mem_ldx_skb(nfp_prog, meta, 4);
+ return mem_ldx(nfp_prog, meta, 4);
+}
+
+static int mem_ldx8(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ return mem_ldx(nfp_prog, meta, 8);
}
static int mem_stx4_skb(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
@@ -1137,6 +1208,9 @@ static int mem_stx4_xdp(struct nfp_prog
static int mem_stx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
+ if (meta->ptr.type == PTR_TO_PACKET)
+ return -EOPNOTSUPP;
+
if (nfp_prog->act == NN_ACT_XDP)
return mem_stx4_xdp(nfp_prog, meta);
return mem_stx4_skb(nfp_prog, meta);
@@ -1354,7 +1428,10 @@ static const instr_cb_t instr_cb[256] =
[BPF_LD | BPF_IND | BPF_B] = data_ind_ld1,
[BPF_LD | BPF_IND | BPF_H] = data_ind_ld2,
[BPF_LD | BPF_IND | BPF_W] = data_ind_ld4,
+ [BPF_LDX | BPF_MEM | BPF_B] = mem_ldx1,
+ [BPF_LDX | BPF_MEM | BPF_H] = mem_ldx2,
[BPF_LDX | BPF_MEM | BPF_W] = mem_ldx4,
+ [BPF_LDX | BPF_MEM | BPF_DW] = mem_ldx8,
[BPF_STX | BPF_MEM | BPF_W] = mem_stx4,
[BPF_JMP | BPF_JA | BPF_K] = jump,
[BPF_JMP | BPF_JEQ | BPF_K] = jeq_imm,
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h
@@ -36,6 +36,7 @@
#include <linux/bitfield.h>
#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
#include <linux/list.h>
#include <linux/types.h>
@@ -96,6 +97,7 @@ typedef int (*instr_cb_t)(struct nfp_pro
/**
* struct nfp_insn_meta - BPF instruction wrapper
* @insn: BPF instruction
+ * @ptr: pointer type for memory operations
* @off: index of first generated machine instruction (in nfp_prog.prog)
* @n: eBPF instruction number
* @skip: skip this instruction (optimized out)
@@ -104,6 +106,7 @@ typedef int (*instr_cb_t)(struct nfp_pro
*/
struct nfp_insn_meta {
struct bpf_insn insn;
+ struct bpf_reg_state ptr;
unsigned int off;
unsigned short n;
bool skip;
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -112,12 +112,19 @@ nfp_bpf_check_exit(struct nfp_prog *nfp_
}
static int
-nfp_bpf_check_ctx_ptr(struct nfp_prog *nfp_prog,
- const struct bpf_verifier_env *env, u8 reg)
+nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
+ const struct bpf_verifier_env *env, u8 reg)
{
- if (env->cur_state.regs[reg].type != PTR_TO_CTX)
+ if (env->cur_state.regs[reg].type != PTR_TO_CTX &&
+ env->cur_state.regs[reg].type != PTR_TO_PACKET)
return -EINVAL;
+ if (meta->ptr.type != NOT_INIT &&
+ meta->ptr.type != env->cur_state.regs[reg].type)
+ return -EINVAL;
+
+ meta->ptr = env->cur_state.regs[reg];
+
return 0;
}
@@ -145,11 +152,11 @@ nfp_verify_insn(struct bpf_verifier_env
return nfp_bpf_check_exit(priv->prog, env);
if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM))
- return nfp_bpf_check_ctx_ptr(priv->prog, env,
- meta->insn.src_reg);
+ return nfp_bpf_check_ptr(priv->prog, meta, env,
+ meta->insn.src_reg);
if ((meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM))
- return nfp_bpf_check_ctx_ptr(priv->prog, env,
- meta->insn.dst_reg);
+ return nfp_bpf_check_ptr(priv->prog, meta, env,
+ meta->insn.dst_reg);
return 0;
}
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.c
@@ -42,6 +42,9 @@
const struct cmd_tgt_act cmd_tgt_act[__CMD_TGT_MAP_SIZE] = {
[CMD_TGT_WRITE8] = { 0x00, 0x42 },
[CMD_TGT_READ8] = { 0x01, 0x43 },
+ [CMD_TGT_READ32] = { 0x00, 0x5c },
+ [CMD_TGT_READ32_LE] = { 0x01, 0x5c },
+ [CMD_TGT_READ32_SWAP] = { 0x02, 0x5c },
[CMD_TGT_READ_LE] = { 0x01, 0x40 },
[CMD_TGT_READ_SWAP_LE] = { 0x03, 0x40 },
};
--- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h
@@ -153,6 +153,7 @@ enum shf_op {
enum shf_sc {
SHF_SC_R_ROT = 0,
+ SHF_SC_NONE = SHF_SC_R_ROT,
SHF_SC_R_SHF = 1,
SHF_SC_L_SHF = 2,
SHF_SC_R_DSHF = 3,
@@ -217,6 +218,9 @@ struct cmd_tgt_act {
enum cmd_tgt_map {
CMD_TGT_READ8,
CMD_TGT_WRITE8,
+ CMD_TGT_READ32,
+ CMD_TGT_READ32_LE,
+ CMD_TGT_READ32_SWAP,
CMD_TGT_READ_LE,
CMD_TGT_READ_SWAP_LE,
__CMD_TGT_MAP_SIZE,