redonkable/alistair23-linux
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nfp: bpf: use a large constant in unresolved branches

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To make absolute relocated branches (branches which will be completely
rewritten with br_set_offset()) distinguishable in user space dumps
from normal jumps add a large offset to them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski 2018-01-10 12:26:03 +00:00 committed by Daniel Borkmann
parent 44a12ecc1c
commit e84797fe15
2 changed files with 13 additions and 7 deletions
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14
drivers/net/ethernet/netronome/nfp/bpf/jit.c
View file

@ -739,7 +739,7 @@ construct_data_ind_ld(struct nfp_prog *nfp_prog, u16 offset, u16 src, u8 size)
imm_a(nfp_prog), ALU_OP_ADD, reg_imm(size));
emit_alu(nfp_prog, reg_none(),
plen_reg(nfp_prog), ALU_OP_SUB, imm_a(nfp_prog));
emit_br_relo(nfp_prog, BR_BLO, 0, 0, RELO_BR_GO_ABORT);
emit_br_relo(nfp_prog, BR_BLO, BR_OFF_RELO, 0, RELO_BR_GO_ABORT);
/* Load data */
return data_ld(nfp_prog, imm_b(nfp_prog), 0, size);
@ -752,7 +752,7 @@ static int construct_data_ld(struct nfp_prog *nfp_prog, u16 offset, u8 size)
/* Check packet length */
tmp_reg = ur_load_imm_any(nfp_prog, offset + size, imm_a(nfp_prog));
emit_alu(nfp_prog, reg_none(), plen_reg(nfp_prog), ALU_OP_SUB, tmp_reg);
emit_br_relo(nfp_prog, BR_BLO, 0, 0, RELO_BR_GO_ABORT);
emit_br_relo(nfp_prog, BR_BLO, BR_OFF_RELO, 0, RELO_BR_GO_ABORT);
/* Load data */
tmp_reg = re_load_imm_any(nfp_prog, offset, imm_b(nfp_prog));
@ -2026,7 +2026,7 @@ static int call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int goto_out(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
emit_br_relo(nfp_prog, BR_UNC, 0, 0, RELO_BR_GO_OUT);
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 0, RELO_BR_GO_OUT);
return 0;
}
@ -2175,7 +2175,7 @@ static void nfp_outro_tc_da(struct nfp_prog *nfp_prog)
/* Target for aborts */
nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);
emit_br_relo(nfp_prog, BR_UNC, 0, 2, RELO_BR_NEXT_PKT);
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2, RELO_BR_NEXT_PKT);
wrp_mov(nfp_prog, reg_a(0), NFP_BPF_ABI_FLAGS);
emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x11), SHF_SC_L_SHF, 16);
@ -2202,7 +2202,7 @@ static void nfp_outro_tc_da(struct nfp_prog *nfp_prog)
emit_shf(nfp_prog, reg_b(2),
reg_imm(0xf), SHF_OP_AND, reg_b(3), SHF_SC_R_SHF, 0);
emit_br_relo(nfp_prog, BR_UNC, 0, 2, RELO_BR_NEXT_PKT);
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2, RELO_BR_NEXT_PKT);
emit_shf(nfp_prog, reg_b(2),
reg_a(2), SHF_OP_OR, reg_b(2), SHF_SC_L_SHF, 4);
@ -2221,7 +2221,7 @@ static void nfp_outro_xdp(struct nfp_prog *nfp_prog)
/* Target for aborts */
nfp_prog->tgt_abort = nfp_prog_current_offset(nfp_prog);
emit_br_relo(nfp_prog, BR_UNC, 0, 2, RELO_BR_NEXT_PKT);
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2, RELO_BR_NEXT_PKT);
wrp_mov(nfp_prog, reg_a(0), NFP_BPF_ABI_FLAGS);
emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_imm(0x82), SHF_SC_L_SHF, 16);
@ -2242,7 +2242,7 @@ static void nfp_outro_xdp(struct nfp_prog *nfp_prog)
emit_shf(nfp_prog, reg_b(2),
reg_imm(0xff), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);
emit_br_relo(nfp_prog, BR_UNC, 0, 2, RELO_BR_NEXT_PKT);
emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2, RELO_BR_NEXT_PKT);
wrp_mov(nfp_prog, reg_a(0), NFP_BPF_ABI_FLAGS);
emit_ld_field(nfp_prog, reg_a(0), 0xc, reg_b(2), SHF_SC_L_SHF, 16);

6
drivers/net/ethernet/netronome/nfp/bpf/main.h
View file

@ -58,6 +58,12 @@ enum nfp_relo_type {
RELO_BR_NEXT_PKT,
};
/* To make absolute relocated branches (branches other than RELO_BR_REL)
* distinguishable in user space dumps from normal jumps, add a large offset
* to them.
*/
#define BR_OFF_RELO 15000
enum static_regs {
STATIC_REG_IMM = 21, /* Bank AB */
STATIC_REG_STACK = 22, /* Bank A */