6db4831e98
Android 14
720 lines
23 KiB
C
720 lines
23 KiB
C
#include <asm/types.h>
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#include <linux/types.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <stddef.h>
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#include <stdbool.h>
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#include <linux/unistd.h>
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#include <linux/filter.h>
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#include <linux/bpf_perf_event.h>
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#include <linux/bpf.h>
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#include <bpf/bpf.h>
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#include "../../../include/linux/filter.h"
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#include "bpf_rlimit.h"
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#include "bpf_util.h"
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#define MAX_INSNS 512
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#define MAX_MATCHES 16
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struct bpf_reg_match {
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unsigned int line;
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const char *match;
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};
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struct bpf_align_test {
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const char *descr;
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struct bpf_insn insns[MAX_INSNS];
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enum {
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UNDEF,
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ACCEPT,
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REJECT
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} result;
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enum bpf_prog_type prog_type;
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/* Matches must be in order of increasing line */
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struct bpf_reg_match matches[MAX_MATCHES];
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};
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static struct bpf_align_test tests[] = {
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/* Four tests of known constants. These aren't staggeringly
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* interesting since we track exact values now.
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*/
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{
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.descr = "mov",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_3, 2),
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BPF_MOV64_IMM(BPF_REG_3, 4),
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BPF_MOV64_IMM(BPF_REG_3, 8),
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BPF_MOV64_IMM(BPF_REG_3, 16),
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BPF_MOV64_IMM(BPF_REG_3, 32),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{1, "R1=ctx(id=0,off=0,imm=0)"},
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{1, "R10=fp0"},
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{1, "R3_w=inv2"},
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{2, "R3_w=inv4"},
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{3, "R3_w=inv8"},
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{4, "R3_w=inv16"},
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{5, "R3_w=inv32"},
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},
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},
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{
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.descr = "shift",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_3, 4),
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BPF_MOV64_IMM(BPF_REG_4, 32),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{1, "R1=ctx(id=0,off=0,imm=0)"},
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{1, "R10=fp0"},
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{1, "R3_w=inv1"},
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{2, "R3_w=inv2"},
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{3, "R3_w=inv4"},
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{4, "R3_w=inv8"},
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{5, "R3_w=inv16"},
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{6, "R3_w=inv1"},
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{7, "R4_w=inv32"},
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{8, "R4_w=inv16"},
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{9, "R4_w=inv8"},
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{10, "R4_w=inv4"},
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{11, "R4_w=inv2"},
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},
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},
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{
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.descr = "addsub",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_3, 4),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 4),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 2),
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BPF_MOV64_IMM(BPF_REG_4, 8),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{1, "R1=ctx(id=0,off=0,imm=0)"},
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{1, "R10=fp0"},
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{1, "R3_w=inv4"},
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{2, "R3_w=inv8"},
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{3, "R3_w=inv10"},
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{4, "R4_w=inv8"},
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{5, "R4_w=inv12"},
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{6, "R4_w=inv14"},
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},
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},
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{
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.descr = "mul",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_3, 7),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 2),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 4),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{1, "R1=ctx(id=0,off=0,imm=0)"},
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{1, "R10=fp0"},
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{1, "R3_w=inv7"},
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{2, "R3_w=inv7"},
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{3, "R3_w=inv14"},
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{4, "R3_w=inv56"},
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},
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},
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/* Tests using unknown values */
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#define PREP_PKT_POINTERS \
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BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, \
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offsetof(struct __sk_buff, data)), \
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BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, \
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offsetof(struct __sk_buff, data_end))
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#define LOAD_UNKNOWN(DST_REG) \
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PREP_PKT_POINTERS, \
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BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), \
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), \
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BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_0, 1), \
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BPF_EXIT_INSN(), \
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BPF_LDX_MEM(BPF_B, DST_REG, BPF_REG_2, 0)
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{
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.descr = "unknown shift",
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.insns = {
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LOAD_UNKNOWN(BPF_REG_3),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
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LOAD_UNKNOWN(BPF_REG_4),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 5),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{7, "R0=pkt(id=0,off=8,r=8,imm=0)"},
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{7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{8, "R3_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
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{9, "R3_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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{10, "R3_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
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{11, "R3_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
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{18, "R3=pkt_end(id=0,off=0,imm=0)"},
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{18, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{19, "R4_w=inv(id=0,umax_value=8160,var_off=(0x0; 0x1fe0))"},
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{20, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
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{21, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
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{22, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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{23, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
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},
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},
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{
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.descr = "unknown mul",
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.insns = {
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LOAD_UNKNOWN(BPF_REG_3),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 1),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 4),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 8),
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BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{8, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{9, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{11, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
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{12, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{13, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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{14, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{15, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
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{16, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
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},
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},
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{
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.descr = "packet const offset",
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.insns = {
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PREP_PKT_POINTERS,
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BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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/* Skip over ethernet header. */
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
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BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
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BPF_EXIT_INSN(),
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BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 0),
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BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 1),
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BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 2),
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BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 3),
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BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 0),
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BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 2),
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BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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{4, "R5_w=pkt(id=0,off=0,r=0,imm=0)"},
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{5, "R5_w=pkt(id=0,off=14,r=0,imm=0)"},
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{6, "R4_w=pkt(id=0,off=14,r=0,imm=0)"},
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{10, "R2=pkt(id=0,off=0,r=18,imm=0)"},
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{10, "R5=pkt(id=0,off=14,r=18,imm=0)"},
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{10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
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{14, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"},
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{15, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"},
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},
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},
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{
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.descr = "packet variable offset",
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.insns = {
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LOAD_UNKNOWN(BPF_REG_6),
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BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
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/* First, add a constant to the R5 packet pointer,
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* then a variable with a known alignment.
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*/
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BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
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BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
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BPF_EXIT_INSN(),
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BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
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/* Now, test in the other direction. Adding first
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* the variable offset to R5, then the constant.
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*/
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BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
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BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
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BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
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BPF_EXIT_INSN(),
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BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
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/* Test multiple accumulations of unknown values
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* into a packet pointer.
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*/
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BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 4),
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BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
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BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
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BPF_EXIT_INSN(),
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BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.prog_type = BPF_PROG_TYPE_SCHED_CLS,
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.matches = {
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/* Calculated offset in R6 has unknown value, but known
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* alignment of 4.
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*/
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{8, "R2=pkt(id=0,off=0,r=8,imm=0)"},
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{8, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* Offset is added to packet pointer R5, resulting in
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* known fixed offset, and variable offset from R6.
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*/
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{11, "R5_w=pkt(id=1,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* At the time the word size load is performed from R5,
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* it's total offset is NET_IP_ALIGN + reg->off (0) +
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* reg->aux_off (14) which is 16. Then the variable
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* offset is considered using reg->aux_off_align which
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* is 4 and meets the load's requirements.
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*/
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{15, "R4=pkt(id=1,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
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{15, "R5=pkt(id=1,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* Variable offset is added to R5 packet pointer,
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* resulting in auxiliary alignment of 4.
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*/
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{18, "R5_w=pkt(id=2,off=0,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* Constant offset is added to R5, resulting in
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* reg->off of 14.
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*/
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{19, "R5_w=pkt(id=2,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* At the time the word size load is performed from R5,
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* its total fixed offset is NET_IP_ALIGN + reg->off
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* (14) which is 16. Then the variable offset is 4-byte
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* aligned, so the total offset is 4-byte aligned and
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* meets the load's requirements.
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*/
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{23, "R4=pkt(id=2,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
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{23, "R5=pkt(id=2,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* Constant offset is added to R5 packet pointer,
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* resulting in reg->off value of 14.
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*/
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{26, "R5_w=pkt(id=0,off=14,r=8"},
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/* Variable offset is added to R5, resulting in a
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* variable offset of (4n).
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*/
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{27, "R5_w=pkt(id=3,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* Constant is added to R5 again, setting reg->off to 18. */
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{28, "R5_w=pkt(id=3,off=18,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
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/* And once more we add a variable; resulting var_off
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* is still (4n), fixed offset is not changed.
|
|
* Also, we create a new reg->id.
|
|
*/
|
|
{29, "R5_w=pkt(id=4,off=18,r=0,umax_value=2040,var_off=(0x0; 0x7fc))"},
|
|
/* At the time the word size load is performed from R5,
|
|
* its total fixed offset is NET_IP_ALIGN + reg->off (18)
|
|
* which is 20. Then the variable offset is (4n), so
|
|
* the total offset is 4-byte aligned and meets the
|
|
* load's requirements.
|
|
*/
|
|
{33, "R4=pkt(id=4,off=22,r=22,umax_value=2040,var_off=(0x0; 0x7fc))"},
|
|
{33, "R5=pkt(id=4,off=18,r=22,umax_value=2040,var_off=(0x0; 0x7fc))"},
|
|
},
|
|
},
|
|
{
|
|
.descr = "packet variable offset 2",
|
|
.insns = {
|
|
/* Create an unknown offset, (4n+2)-aligned */
|
|
LOAD_UNKNOWN(BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
|
|
/* Add it to the packet pointer */
|
|
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
|
|
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
|
|
/* Check bounds and perform a read */
|
|
BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
|
|
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
|
|
BPF_EXIT_INSN(),
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
|
|
/* Make a (4n) offset from the value we just read */
|
|
BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xff),
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
|
|
/* Add it to the packet pointer */
|
|
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
|
|
/* Check bounds and perform a read */
|
|
BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
|
|
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
|
|
BPF_EXIT_INSN(),
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
|
|
.matches = {
|
|
/* Calculated offset in R6 has unknown value, but known
|
|
* alignment of 4.
|
|
*/
|
|
{8, "R2=pkt(id=0,off=0,r=8,imm=0)"},
|
|
{8, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
|
|
/* Adding 14 makes R6 be (4n+2) */
|
|
{9, "R6_w=inv(id=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
/* Packet pointer has (4n+2) offset */
|
|
{11, "R5_w=pkt(id=1,off=0,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
{13, "R4=pkt(id=1,off=4,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
/* At the time the word size load is performed from R5,
|
|
* its total fixed offset is NET_IP_ALIGN + reg->off (0)
|
|
* which is 2. Then the variable offset is (4n+2), so
|
|
* the total offset is 4-byte aligned and meets the
|
|
* load's requirements.
|
|
*/
|
|
{15, "R5=pkt(id=1,off=0,r=4,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
/* Newly read value in R6 was shifted left by 2, so has
|
|
* known alignment of 4.
|
|
*/
|
|
{18, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
|
|
/* Added (4n) to packet pointer's (4n+2) var_off, giving
|
|
* another (4n+2).
|
|
*/
|
|
{19, "R5_w=pkt(id=2,off=0,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
|
|
{21, "R4=pkt(id=2,off=4,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
|
|
/* At the time the word size load is performed from R5,
|
|
* its total fixed offset is NET_IP_ALIGN + reg->off (0)
|
|
* which is 2. Then the variable offset is (4n+2), so
|
|
* the total offset is 4-byte aligned and meets the
|
|
* load's requirements.
|
|
*/
|
|
{23, "R5=pkt(id=2,off=0,r=4,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
|
|
},
|
|
},
|
|
{
|
|
.descr = "dubious pointer arithmetic",
|
|
.insns = {
|
|
PREP_PKT_POINTERS,
|
|
BPF_MOV64_IMM(BPF_REG_0, 0),
|
|
/* (ptr - ptr) << 2 */
|
|
BPF_MOV64_REG(BPF_REG_5, BPF_REG_3),
|
|
BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_2),
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_5, 2),
|
|
/* We have a (4n) value. Let's make a packet offset
|
|
* out of it. First add 14, to make it a (4n+2)
|
|
*/
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
|
|
/* Then make sure it's nonnegative */
|
|
BPF_JMP_IMM(BPF_JSGE, BPF_REG_5, 0, 1),
|
|
BPF_EXIT_INSN(),
|
|
/* Add it to packet pointer */
|
|
BPF_MOV64_REG(BPF_REG_6, BPF_REG_2),
|
|
BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_5),
|
|
/* Check bounds and perform a read */
|
|
BPF_MOV64_REG(BPF_REG_4, BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
|
|
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
|
|
BPF_EXIT_INSN(),
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_6, 0),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
|
|
.result = REJECT,
|
|
.matches = {
|
|
{4, "R5_w=pkt_end(id=0,off=0,imm=0)"},
|
|
/* (ptr - ptr) << 2 == unknown, (4n) */
|
|
{6, "R5_w=inv(id=0,smax_value=9223372036854775804,umax_value=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc))"},
|
|
/* (4n) + 14 == (4n+2). We blow our bounds, because
|
|
* the add could overflow.
|
|
*/
|
|
{7, "R5=inv(id=0,var_off=(0x2; 0xfffffffffffffffc))"},
|
|
/* Checked s>=0 */
|
|
{9, "R5=inv(id=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
|
|
/* packet pointer + nonnegative (4n+2) */
|
|
{11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
|
|
{13, "R4=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
|
|
/* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine.
|
|
* We checked the bounds, but it might have been able
|
|
* to overflow if the packet pointer started in the
|
|
* upper half of the address space.
|
|
* So we did not get a 'range' on R6, and the access
|
|
* attempt will fail.
|
|
*/
|
|
{15, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
|
|
}
|
|
},
|
|
{
|
|
.descr = "variable subtraction",
|
|
.insns = {
|
|
/* Create an unknown offset, (4n+2)-aligned */
|
|
LOAD_UNKNOWN(BPF_REG_6),
|
|
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
|
|
/* Create another unknown, (4n)-aligned, and subtract
|
|
* it from the first one
|
|
*/
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2),
|
|
BPF_ALU64_REG(BPF_SUB, BPF_REG_6, BPF_REG_7),
|
|
/* Bounds-check the result */
|
|
BPF_JMP_IMM(BPF_JSGE, BPF_REG_6, 0, 1),
|
|
BPF_EXIT_INSN(),
|
|
/* Add it to the packet pointer */
|
|
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
|
|
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
|
|
/* Check bounds and perform a read */
|
|
BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
|
|
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
|
|
BPF_EXIT_INSN(),
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
|
|
.matches = {
|
|
/* Calculated offset in R6 has unknown value, but known
|
|
* alignment of 4.
|
|
*/
|
|
{7, "R2=pkt(id=0,off=0,r=8,imm=0)"},
|
|
{9, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
|
|
/* Adding 14 makes R6 be (4n+2) */
|
|
{10, "R6_w=inv(id=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
/* New unknown value in R7 is (4n) */
|
|
{11, "R7_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
|
|
/* Subtracting it from R6 blows our unsigned bounds */
|
|
{12, "R6=inv(id=0,smin_value=-1006,smax_value=1034,var_off=(0x2; 0xfffffffffffffffc))"},
|
|
/* Checked s>= 0 */
|
|
{14, "R6=inv(id=0,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
/* At the time the word size load is performed from R5,
|
|
* its total fixed offset is NET_IP_ALIGN + reg->off (0)
|
|
* which is 2. Then the variable offset is (4n+2), so
|
|
* the total offset is 4-byte aligned and meets the
|
|
* load's requirements.
|
|
*/
|
|
{20, "R5=pkt(id=1,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc))"},
|
|
},
|
|
},
|
|
{
|
|
.descr = "pointer variable subtraction",
|
|
.insns = {
|
|
/* Create an unknown offset, (4n+2)-aligned and bounded
|
|
* to [14,74]
|
|
*/
|
|
LOAD_UNKNOWN(BPF_REG_6),
|
|
BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
|
|
BPF_ALU64_IMM(BPF_AND, BPF_REG_6, 0xf),
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 14),
|
|
/* Subtract it from the packet pointer */
|
|
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
|
|
BPF_ALU64_REG(BPF_SUB, BPF_REG_5, BPF_REG_6),
|
|
/* Create another unknown, (4n)-aligned and >= 74.
|
|
* That in fact means >= 76, since 74 % 4 == 2
|
|
*/
|
|
BPF_ALU64_IMM(BPF_LSH, BPF_REG_7, 2),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 76),
|
|
/* Add it to the packet pointer */
|
|
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_7),
|
|
/* Check bounds and perform a read */
|
|
BPF_MOV64_REG(BPF_REG_4, BPF_REG_5),
|
|
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
|
|
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_4, 1),
|
|
BPF_EXIT_INSN(),
|
|
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_5, 0),
|
|
BPF_EXIT_INSN(),
|
|
},
|
|
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
|
|
.matches = {
|
|
/* Calculated offset in R6 has unknown value, but known
|
|
* alignment of 4.
|
|
*/
|
|
{7, "R2=pkt(id=0,off=0,r=8,imm=0)"},
|
|
{10, "R6_w=inv(id=0,umax_value=60,var_off=(0x0; 0x3c))"},
|
|
/* Adding 14 makes R6 be (4n+2) */
|
|
{11, "R6_w=inv(id=0,umin_value=14,umax_value=74,var_off=(0x2; 0x7c))"},
|
|
/* Subtracting from packet pointer overflows ubounds */
|
|
{13, "R5_w=pkt(id=1,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c))"},
|
|
/* New unknown value in R7 is (4n), >= 76 */
|
|
{15, "R7_w=inv(id=0,umin_value=76,umax_value=1096,var_off=(0x0; 0x7fc))"},
|
|
/* Adding it to packet pointer gives nice bounds again */
|
|
{16, "R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"},
|
|
/* At the time the word size load is performed from R5,
|
|
* its total fixed offset is NET_IP_ALIGN + reg->off (0)
|
|
* which is 2. Then the variable offset is (4n+2), so
|
|
* the total offset is 4-byte aligned and meets the
|
|
* load's requirements.
|
|
*/
|
|
{20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"},
|
|
},
|
|
},
|
|
};
|
|
|
|
static int probe_filter_length(const struct bpf_insn *fp)
|
|
{
|
|
int len;
|
|
|
|
for (len = MAX_INSNS - 1; len > 0; --len)
|
|
if (fp[len].code != 0 || fp[len].imm != 0)
|
|
break;
|
|
return len + 1;
|
|
}
|
|
|
|
static char bpf_vlog[32768];
|
|
|
|
static int do_test_single(struct bpf_align_test *test)
|
|
{
|
|
struct bpf_insn *prog = test->insns;
|
|
int prog_type = test->prog_type;
|
|
char bpf_vlog_copy[32768];
|
|
const char *line_ptr;
|
|
int cur_line = -1;
|
|
int prog_len, i;
|
|
int fd_prog;
|
|
int ret;
|
|
|
|
prog_len = probe_filter_length(prog);
|
|
fd_prog = bpf_verify_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER,
|
|
prog, prog_len, 1, "GPL", 0,
|
|
bpf_vlog, sizeof(bpf_vlog), 2);
|
|
if (fd_prog < 0 && test->result != REJECT) {
|
|
printf("Failed to load program.\n");
|
|
printf("%s", bpf_vlog);
|
|
ret = 1;
|
|
} else if (fd_prog >= 0 && test->result == REJECT) {
|
|
printf("Unexpected success to load!\n");
|
|
printf("%s", bpf_vlog);
|
|
ret = 1;
|
|
close(fd_prog);
|
|
} else {
|
|
ret = 0;
|
|
/* We make a local copy so that we can strtok() it */
|
|
strncpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy));
|
|
line_ptr = strtok(bpf_vlog_copy, "\n");
|
|
for (i = 0; i < MAX_MATCHES; i++) {
|
|
struct bpf_reg_match m = test->matches[i];
|
|
|
|
if (!m.match)
|
|
break;
|
|
while (line_ptr) {
|
|
cur_line = -1;
|
|
sscanf(line_ptr, "%u: ", &cur_line);
|
|
if (cur_line == m.line)
|
|
break;
|
|
line_ptr = strtok(NULL, "\n");
|
|
}
|
|
if (!line_ptr) {
|
|
printf("Failed to find line %u for match: %s\n",
|
|
m.line, m.match);
|
|
ret = 1;
|
|
printf("%s", bpf_vlog);
|
|
break;
|
|
}
|
|
if (!strstr(line_ptr, m.match)) {
|
|
printf("Failed to find match %u: %s\n",
|
|
m.line, m.match);
|
|
ret = 1;
|
|
printf("%s", bpf_vlog);
|
|
break;
|
|
}
|
|
}
|
|
if (fd_prog >= 0)
|
|
close(fd_prog);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int do_test(unsigned int from, unsigned int to)
|
|
{
|
|
int all_pass = 0;
|
|
int all_fail = 0;
|
|
unsigned int i;
|
|
|
|
for (i = from; i < to; i++) {
|
|
struct bpf_align_test *test = &tests[i];
|
|
int fail;
|
|
|
|
printf("Test %3d: %s ... ",
|
|
i, test->descr);
|
|
fail = do_test_single(test);
|
|
if (fail) {
|
|
all_fail++;
|
|
printf("FAIL\n");
|
|
} else {
|
|
all_pass++;
|
|
printf("PASS\n");
|
|
}
|
|
}
|
|
printf("Results: %d pass %d fail\n",
|
|
all_pass, all_fail);
|
|
return all_fail ? EXIT_FAILURE : EXIT_SUCCESS;
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
unsigned int from = 0, to = ARRAY_SIZE(tests);
|
|
|
|
if (argc == 3) {
|
|
unsigned int l = atoi(argv[argc - 2]);
|
|
unsigned int u = atoi(argv[argc - 1]);
|
|
|
|
if (l < to && u < to) {
|
|
from = l;
|
|
to = u + 1;
|
|
}
|
|
} else if (argc == 2) {
|
|
unsigned int t = atoi(argv[argc - 1]);
|
|
|
|
if (t < to) {
|
|
from = t;
|
|
to = t + 1;
|
|
}
|
|
}
|
|
return do_test(from, to);
|
|
}
|