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android-kvm / linux / e2ab4ef83fe279e6f8e06ffa490144d082b95493 / . / tools / testing / selftests / bpf / test_align.c
blob: 0262f7b374f9cf0df0eb5fa789f16c5abd92d21f [file] [log] [blame]
#include <asm/types.h>
#include <linux/types.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stddef.h>
#include <stdbool.h>
#include <linux/unistd.h>
#include <linux/filter.h>
#include <linux/bpf_perf_event.h>
#include <linux/bpf.h>
#include <bpf/bpf.h>
#include "../../../include/linux/filter.h"
#include "bpf_rlimit.h"
#include "bpf_util.h"
#define MAX_INSNS 512
#define MAX_MATCHES 16
struct bpf_reg_match {
unsigned int line;
const char *match;
};
struct bpf_align_test {
const char *descr;
struct bpf_insn insns[MAX_INSNS];
enum {
UNDEF,
ACCEPT,
REJECT
} result;
enum bpf_prog_type prog_type;
/* Matches must be in order of increasing line */
struct bpf_reg_match matches[MAX_MATCHES];
};
static struct bpf_align_test tests[] = {
/* Four tests of known constants. These aren't staggeringly
* interesting since we track exact values now.
*/
{
.descr = "mov",
.insns = {
BPF_MOV64_IMM(BPF_REG_3, 2),
BPF_MOV64_IMM(BPF_REG_3, 4),
BPF_MOV64_IMM(BPF_REG_3, 8),
BPF_MOV64_IMM(BPF_REG_3, 16),
BPF_MOV64_IMM(BPF_REG_3, 32),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{1, "R1=ctx(id=0,off=0,imm=0)"},
{1, "R10=fp0"},
{1, "R3_w=inv2"},
{2, "R3_w=inv4"},
{3, "R3_w=inv8"},
{4, "R3_w=inv16"},
{5, "R3_w=inv32"},
},
},
{
.descr = "shift",
.insns = {
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_3, 4),
BPF_MOV64_IMM(BPF_REG_4, 32),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{1, "R1=ctx(id=0,off=0,imm=0)"},
{1, "R10=fp0"},
{1, "R3_w=inv1"},
{2, "R3_w=inv2"},
{3, "R3_w=inv4"},
{4, "R3_w=inv8"},
{5, "R3_w=inv16"},
{6, "R3_w=inv1"},
{7, "R4_w=inv32"},
{8, "R4_w=inv16"},
{9, "R4_w=inv8"},
{10, "R4_w=inv4"},
{11, "R4_w=inv2"},
},
},
{
.descr = "addsub",
.insns = {
BPF_MOV64_IMM(BPF_REG_3, 4),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 4),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 2),
BPF_MOV64_IMM(BPF_REG_4, 8),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 4),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{1, "R1=ctx(id=0,off=0,imm=0)"},
{1, "R10=fp0"},
{1, "R3_w=inv4"},
{2, "R3_w=inv8"},
{3, "R3_w=inv10"},
{4, "R4_w=inv8"},
{5, "R4_w=inv12"},
{6, "R4_w=inv14"},
},
},
{
.descr = "mul",
.insns = {
BPF_MOV64_IMM(BPF_REG_3, 7),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 2),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_3, 4),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{1, "R1=ctx(id=0,off=0,imm=0)"},
{1, "R10=fp0"},
{1, "R3_w=inv7"},
{2, "R3_w=inv7"},
{3, "R3_w=inv14"},
{4, "R3_w=inv56"},
},
},
/* Tests using unknown values */
#define PREP_PKT_POINTERS \
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, \
offsetof(struct __sk_buff, data)), \
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, \
offsetof(struct __sk_buff, data_end))
#define LOAD_UNKNOWN(DST_REG) \
PREP_PKT_POINTERS, \
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), \
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), \
BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_0, 1), \
BPF_EXIT_INSN(), \
BPF_LDX_MEM(BPF_B, DST_REG, BPF_REG_2, 0)
{
.descr = "unknown shift",
.insns = {
LOAD_UNKNOWN(BPF_REG_3),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_3, 1),
LOAD_UNKNOWN(BPF_REG_4),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 5),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_ALU64_IMM(BPF_RSH, BPF_REG_4, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{7, "R0_w=pkt(id=0,off=8,r=8,imm=0)"},
{7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{8, "R3_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
{9, "R3_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
{10, "R3_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
{11, "R3_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
{18, "R3=pkt_end(id=0,off=0,imm=0)"},
{18, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{19, "R4_w=inv(id=0,umax_value=8160,var_off=(0x0; 0x1fe0))"},
{20, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
{21, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
{22, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
{23, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
},
},
{
.descr = "unknown mul",
.insns = {
LOAD_UNKNOWN(BPF_REG_3),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 1),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 4),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_3),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 8),
BPF_ALU64_IMM(BPF_MUL, BPF_REG_4, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{7, "R3_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{8, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{9, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{11, "R4_w=inv(id=0,umax_value=510,var_off=(0x0; 0x1fe))"},
{12, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{13, "R4_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
{14, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{15, "R4_w=inv(id=0,umax_value=2040,var_off=(0x0; 0x7f8))"},
{16, "R4_w=inv(id=0,umax_value=4080,var_off=(0x0; 0xff0))"},
},
},
{
.descr = "packet const offset",
.insns = {
PREP_PKT_POINTERS,
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
BPF_MOV64_IMM(BPF_REG_0, 0),
/* Skip over ethernet header. */
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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_B, BPF_REG_4, BPF_REG_5, 0),
BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 1),
BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 2),
BPF_LDX_MEM(BPF_B, BPF_REG_4, BPF_REG_5, 3),
BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 0),
BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_5, 2),
BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_5, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.matches = {
{4, "R5_w=pkt(id=0,off=0,r=0,imm=0)"},
{5, "R5_w=pkt(id=0,off=14,r=0,imm=0)"},
{6, "R4_w=pkt(id=0,off=14,r=0,imm=0)"},
{10, "R2=pkt(id=0,off=0,r=18,imm=0)"},
{10, "R5=pkt(id=0,off=14,r=18,imm=0)"},
{10, "R4_w=inv(id=0,umax_value=255,var_off=(0x0; 0xff))"},
{14, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"},
{15, "R4_w=inv(id=0,umax_value=65535,var_off=(0x0; 0xffff))"},
},
},
{
.descr = "packet variable offset",
.insns = {
LOAD_UNKNOWN(BPF_REG_6),
BPF_ALU64_IMM(BPF_LSH, BPF_REG_6, 2),
/* First, add a constant to the R5 packet pointer,
* then a variable with a known alignment.
*/
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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_4, BPF_REG_5, 0),
/* Now, test in the other direction. Adding first
* the variable offset to R5, then the constant.
*/
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
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_4, BPF_REG_5, 0),
/* Test multiple accumulations of unknown values
* into a packet pointer.
*/
BPF_MOV64_REG(BPF_REG_5, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 14),
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_5, BPF_REG_6),
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_4, 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_w=pkt(id=0,off=0,r=8,imm=0)"},
{8, "R6_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* Offset is added to packet pointer R5, resulting in
* known fixed offset, and variable offset from R6.
*/
{11, "R5_w=pkt(id=1,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* At the time the word size load is performed from R5,
* it's total offset is NET_IP_ALIGN + reg->off (0) +
* reg->aux_off (14) which is 16. Then the variable
* offset is considered using reg->aux_off_align which
* is 4 and meets the load's requirements.
*/
{15, "R4=pkt(id=1,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
{15, "R5=pkt(id=1,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* Variable offset is added to R5 packet pointer,
* resulting in auxiliary alignment of 4.
*/
{18, "R5_w=pkt(id=2,off=0,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* Constant offset is added to R5, resulting in
* reg->off of 14.
*/
{19, "R5_w=pkt(id=2,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* At the time the word size load is performed from R5,
* its total fixed offset is NET_IP_ALIGN + reg->off
* (14) which is 16. Then the variable offset is 4-byte
* aligned, so the total offset is 4-byte aligned and
* meets the load's requirements.
*/
{23, "R4=pkt(id=2,off=18,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
{23, "R5=pkt(id=2,off=14,r=18,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* Constant offset is added to R5 packet pointer,
* resulting in reg->off value of 14.
*/
{26, "R5_w=pkt(id=0,off=14,r=8"},
/* Variable offset is added to R5, resulting in a
* variable offset of (4n).
*/
{27, "R5_w=pkt(id=3,off=14,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* Constant is added to R5 again, setting reg->off to 18. */
{28, "R5_w=pkt(id=3,off=18,r=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
/* And once more we add a variable; resulting var_off
* 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_w=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_w=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_w=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_w=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_w=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_w=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, BPF_F_STRICT_ALIGNMENT,
"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);
}