tools/testing/selftests/bpf/progs/compute_live_registers.c

root/tools/testing/selftests/bpf/progs/compute_live_registers.c
// SPDX-License-Identifier: GPL-2.0

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "../../../include/linux/filter.h"
#include "bpf_arena_common.h"
#include "bpf_misc.h"

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __uint(max_entries, 1);
        __type(key, __u32);
        __type(value, __u64);
} test_map SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_ARENA);
        __uint(map_flags, BPF_F_MMAPABLE);
        __uint(max_entries, 1);
} arena SEC(".maps");

SEC("socket")
__log_level(2)
__msg(" 0: .......... (b7) r0 = 42")
__msg(" 1: 0......... (bf) r1 = r0")
__msg(" 2: .1........ (bf) r2 = r1")
__msg(" 3: ..2....... (bf) r3 = r2")
__msg(" 4: ...3...... (bf) r4 = r3")
__msg(" 5: ....4..... (bf) r5 = r4")
__msg(" 6: .....5.... (bf) r6 = r5")
__msg(" 7: ......6... (bf) r7 = r6")
__msg(" 8: .......7.. (bf) r8 = r7")
__msg(" 9: ........8. (bf) r9 = r8")
__msg("10: .........9 (bf) r0 = r9")
__msg("11: 0......... (95) exit")
__naked void assign_chain(void)
{
        asm volatile (
                "r0 = 42;"
                "r1 = r0;"
                "r2 = r1;"
                "r3 = r2;"
                "r4 = r3;"
                "r5 = r4;"
                "r6 = r5;"
                "r7 = r6;"
                "r8 = r7;"
                "r9 = r8;"
                "r0 = r9;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("0: .......... (b7) r1 = 7")
__msg("1: .1........ (07) r1 += 7")
__msg("2: .......... (b7) r2 = 7")
__msg("3: ..2....... (b7) r3 = 42")
__msg("4: ..23...... (0f) r2 += r3")
__msg("5: .......... (b7) r0 = 0")
__msg("6: 0......... (95) exit")
__naked void arithmetics(void)
{
        asm volatile (
                "r1 = 7;"
                "r1 += 7;"
                "r2 = 7;"
                "r3 = 42;"
                "r2 += r3;"
                "r0 = 0;"
                "exit;"
                ::: __clobber_all);
}

#ifdef CAN_USE_BPF_ST
SEC("socket")
__log_level(2)
__msg("  1: .1........ (07) r1 += -8")
__msg("  2: .1........ (7a) *(u64 *)(r1 +0) = 7")
__msg("  3: .1........ (b7) r2 = 42")
__msg("  4: .12....... (7b) *(u64 *)(r1 +0) = r2")
__msg("  5: .12....... (7b) *(u64 *)(r1 +0) = r2")
__msg("  6: .......... (b7) r0 = 0")
__naked void store(void)
{
        asm volatile (
                "r1 = r10;"
                "r1 += -8;"
                "*(u64 *)(r1 +0) = 7;"
                "r2 = 42;"
                "*(u64 *)(r1 +0) = r2;"
                "*(u64 *)(r1 +0) = r2;"
                "r0 = 0;"
                "exit;"
                ::: __clobber_all);
}
#endif

SEC("socket")
__log_level(2)
__msg("1: ....4..... (07) r4 += -8")
__msg("2: ....4..... (79) r5 = *(u64 *)(r4 +0)")
__msg("3: ....45.... (07) r4 += -8")
__naked void load(void)
{
        asm volatile (
                "r4 = r10;"
                "r4 += -8;"
                "r5 = *(u64 *)(r4 +0);"
                "r4 += -8;"
                "r0 = r5;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("0: .1........ (61) r2 = *(u32 *)(r1 +0)")
__msg("1: ..2....... (d4) r2 = le64 r2")
__msg("2: ..2....... (bf) r0 = r2")
__naked void endian(void)
{
        asm volatile (
                "r2 = *(u32 *)(r1 +0);"
                "r2 = le64 r2;"
                "r0 = r2;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg(" 8: 0......... (b7) r1 = 1")
__msg(" 9: 01........ (db) r1 = atomic64_fetch_add((u64 *)(r0 +0), r1)")
__msg("10: 01........ (c3) lock *(u32 *)(r0 +0) += r1")
__msg("11: 01........ (db) r1 = atomic64_xchg((u64 *)(r0 +0), r1)")
__msg("12: 01........ (bf) r2 = r0")
__msg("13: .12....... (bf) r0 = r1")
__msg("14: 012....... (db) r0 = atomic64_cmpxchg((u64 *)(r2 +0), r0, r1)")
__naked void atomic(void)
{
        asm volatile (
                "r2 = r10;"
                "r2 += -8;"
                "r1 = 0;"
                "*(u64 *)(r2 +0) = r1;"
                "r1 = %[test_map] ll;"
                "call %[bpf_map_lookup_elem];"
                "if r0 == 0 goto 1f;"
                "r1 = 1;"
                "r1 = atomic_fetch_add((u64 *)(r0 +0), r1);"
                ".8byte %[add_nofetch];" /* same as "lock *(u32 *)(r0 +0) += r1;" */
                "r1 = xchg_64(r0 + 0, r1);"
                "r2 = r0;"
                "r0 = r1;"
                "r0 = cmpxchg_64(r2 + 0, r0, r1);"
                "1: exit;"
                :
                : __imm(bpf_map_lookup_elem),
                  __imm_addr(test_map),
                  __imm_insn(add_nofetch, BPF_ATOMIC_OP(BPF_W, BPF_ADD, BPF_REG_0, BPF_REG_1, 0))
                : __clobber_all);
}

#ifdef CAN_USE_LOAD_ACQ_STORE_REL

SEC("socket")
__log_level(2)
__msg("2: .12....... (db) store_release((u64 *)(r2 -8), r1)")
__msg("3: .......... (bf) r3 = r10")
__msg("4: ...3...... (db) r4 = load_acquire((u64 *)(r3 -8))")
__naked void atomic_load_acq_store_rel(void)
{
        asm volatile (
                "r1 = 42;"
                "r2 = r10;"
                ".8byte %[store_release_insn];" /* store_release((u64 *)(r2 - 8), r1); */
                "r3 = r10;"
                ".8byte %[load_acquire_insn];" /* r4 = load_acquire((u64 *)(r3 + 0)); */
                "r0 = r4;"
                "exit;"
                :
                : __imm_insn(store_release_insn,
                             BPF_ATOMIC_OP(BPF_DW, BPF_STORE_REL, BPF_REG_2, BPF_REG_1, -8)),
                  __imm_insn(load_acquire_insn,
                             BPF_ATOMIC_OP(BPF_DW, BPF_LOAD_ACQ, BPF_REG_4, BPF_REG_3, -8))
                : __clobber_all);
}

#endif /* CAN_USE_LOAD_ACQ_STORE_REL */

SEC("socket")
__log_level(2)
__msg("4: .12....7.. (85) call bpf_trace_printk#6")
__msg("5: 0......7.. (0f) r0 += r7")
__naked void regular_call(void)
{
        asm volatile (
                "r7 = 1;"
                "r1 = r10;"
                "r1 += -8;"
                "r2 = 1;"
                "call %[bpf_trace_printk];"
                "r0 += r7;"
                "exit;"
                :
                : __imm(bpf_trace_printk)
                : __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("2: 012....... (25) if r1 > 0x7 goto pc+1")
__msg("3: ..2....... (bf) r0 = r2")
__naked void if1(void)
{
        asm volatile (
                "r0 = 1;"
                "r2 = 2;"
                "if r1 > 0x7 goto +1;"
                "r0 = r2;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("3: 0123...... (2d) if r1 > r3 goto pc+1")
__msg("4: ..2....... (bf) r0 = r2")
__naked void if2(void)
{
        asm volatile (
                "r0 = 1;"
                "r2 = 2;"
                "r3 = 7;"
                "if r1 > r3 goto +1;"
                "r0 = r2;"
                "exit;"
                ::: __clobber_all);
}

/* Verifier misses that r2 is alive if jset is not handled properly */
SEC("socket")
__log_level(2)
__msg("2: 012....... (45) if r1 & 0x7 goto pc+1")
__naked void if3_jset_bug(void)
{
        asm volatile (
                "r0 = 1;"
                "r2 = 2;"
                "if r1 & 0x7 goto +1;"
                "exit;"
                "r0 = r2;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("0: .......... (b7) r1 = 0")
__msg("1: .1........ (b7) r2 = 7")
__msg("2: .12....... (25) if r1 > 0x7 goto pc+4")
__msg("3: .12....... (07) r1 += 1")
__msg("4: .12....... (27) r2 *= 2")
__msg("5: .12....... (05) goto pc+0")
__msg("6: .12....... (05) goto pc-5")
__msg("7: .......... (b7) r0 = 0")
__msg("8: 0......... (95) exit")
__naked void loop(void)
{
        asm volatile (
                "r1 = 0;"
                "r2 = 7;"
                "if r1 > 0x7 goto +4;"
                "r1 += 1;"
                "r2 *= 2;"
                "goto +0;"
                "goto -5;"
                "r0 = 0;"
                "exit;"
                :
                : __imm(bpf_trace_printk)
                : __clobber_all);
}

#ifdef CAN_USE_GOTOL
SEC("socket")
__log_level(2)
__msg("2: .123...... (25) if r1 > 0x7 goto pc+2")
__msg("3: ..2....... (bf) r0 = r2")
__msg("4: 0......... (06) gotol pc+1")
__msg("5: ...3...... (bf) r0 = r3")
__msg("6: 0......... (95) exit")
__naked void gotol(void)
{
        asm volatile (
                "r2 = 42;"
                "r3 = 24;"
                "if r1 > 0x7 goto +2;"
                "r0 = r2;"
                "gotol +1;"
                "r0 = r3;"
                "exit;"
                :
                : __imm(bpf_trace_printk)
                : __clobber_all);
}
#endif

SEC("socket")
__log_level(2)
__msg("0: .......... (b7) r1 = 1")
__msg("1: .1........ (e5) may_goto pc+1")
__msg("2: .......... (05) goto pc-3")
__msg("3: .1........ (bf) r0 = r1")
__msg("4: 0......... (95) exit")
__naked void may_goto(void)
{
        asm volatile (
        "1: r1 = 1;"
        ".8byte %[may_goto];"
        "goto 1b;"
        "r0 = r1;"
        "exit;"
        :
        : __imm(bpf_get_smp_processor_id),
          __imm_insn(may_goto, BPF_RAW_INSN(BPF_JMP | BPF_JCOND, 0, 0, +1 /* offset */, 0))
        : __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("1: 0......... (18) r2 = 0x7")
__msg("3: 0.2....... (0f) r0 += r2")
__naked void ldimm64(void)
{
        asm volatile (
                "r0 = 0;"
                "r2 = 0x7 ll;"
                "r0 += r2;"
                "exit;"
                :
                :: __clobber_all);
}

/* No rules specific for LD_ABS/LD_IND, default behaviour kicks in */
SEC("socket")
__log_level(2)
__msg("2: 0123456789 (30) r0 = *(u8 *)skb[42]")
__msg("3: 012.456789 (0f) r7 += r0")
__msg("4: 012.456789 (b7) r3 = 42")
__msg("5: 0123456789 (50) r0 = *(u8 *)skb[r3 + 0]")
__msg("6: 0......7.. (0f) r7 += r0")
__naked void ldabs(void)
{
        asm volatile (
                "r6 = r1;"
                "r7 = 0;"
                "r0 = *(u8 *)skb[42];"
                "r7 += r0;"
                "r3 = 42;"
                ".8byte %[ld_ind];" /* same as "r0 = *(u8 *)skb[r3];" */
                "r7 += r0;"
                "r0 = r7;"
                "exit;"
                :
                : __imm_insn(ld_ind, BPF_LD_IND(BPF_B, BPF_REG_3, 0))
                : __clobber_all);
}


#ifdef __BPF_FEATURE_ADDR_SPACE_CAST
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
__log_level(2)
__msg(" 6: .12345.... (85) call bpf_arena_alloc_pages")
__msg(" 7: 0......... (bf) r1 = addr_space_cast(r0, 0, 1)")
__msg(" 8: .1........ (b7) r2 = 42")
__naked void addr_space_cast(void)
{
        asm volatile (
                "r1 = %[arena] ll;"
                "r2 = 0;"
                "r3 = 1;"
                "r4 = 0;"
                "r5 = 0;"
                "call %[bpf_arena_alloc_pages];"
                "r1 = addr_space_cast(r0, 0, 1);"
                "r2 = 42;"
                "*(u64 *)(r1 +0) = r2;"
                "r0 = 0;"
                "exit;"
                :
                : __imm(bpf_arena_alloc_pages),
                  __imm_addr(arena)
                : __clobber_all);
}
#endif

static __used __naked int aux1(void)
{
        asm volatile (
                "r0 = r1;"
                "r0 += r2;"
                "exit;"
                ::: __clobber_all);
}

SEC("socket")
__log_level(2)
__msg("0: ....45.... (b7) r1 = 1")
__msg("1: .1..45.... (b7) r2 = 2")
__msg("2: .12.45.... (b7) r3 = 3")
/* Conservative liveness for subprog parameters. */
__msg("3: .12345.... (85) call pc+2")
__msg("4: .......... (b7) r0 = 0")
__msg("5: 0......... (95) exit")
__msg("6: .12....... (bf) r0 = r1")
__msg("7: 0.2....... (0f) r0 += r2")
/* Conservative liveness for subprog return value. */
__msg("8: 0......... (95) exit")
__naked void subprog1(void)
{
        asm volatile (
                "r1 = 1;"
                "r2 = 2;"
                "r3 = 3;"
                "call aux1;"
                "r0 = 0;"
                "exit;"
                ::: __clobber_all);
}

#if defined(__TARGET_ARCH_x86) || defined(__TARGET_ARCH_arm64)

SEC("socket")
__log_level(2)
__msg("2: .1........ (07) r1 += 8")
__msg("3: .1........ (79) r2 = *(u64 *)(r1 +0)")
__msg("4: ..2....... (b7) r3 = 1")
__msg("5: ..23...... (b7) r4 = 2")
__msg("6: ..234..... (0d) gotox r2")
__msg("7: ...3...... (bf) r0 = r3")
__msg("8: 0......... (95) exit")
__msg("9: ....4..... (bf) r0 = r4")
__msg("10: 0......... (95) exit")
__naked
void gotox(void)
{
        asm volatile (
        ".pushsection .jumptables,\"\",@progbits;"
"jt0_%=: .quad l0_%= - socket;"
        ".quad l1_%= - socket;"
        ".size jt0_%=, 16;"
        ".global jt0_%=;"
        ".popsection;"

        "r1 = jt0_%= ll;"
        "r1 += 8;"
        "r2 = *(u64 *)(r1 + 0);"
        "r3 = 1;"
        "r4 = 2;"
        ".8byte %[gotox_r2];"
"l0_%=:  r0 = r3;"
        "exit;"
"l1_%=:  r0 = r4;"
        "exit;"
        :
        : __imm_insn(gotox_r2, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_2, BPF_REG_0, 0, 0))
        : __clobber_all);
}

#endif /* __TARGET_ARCH_x86 || __TARGET_ARCH_arm64 */

/* to retain debug info for BTF generation */
void kfunc_root(void)
{
        bpf_arena_alloc_pages(0, 0, 0, 0, 0);
}

char _license[] SEC("license") = "GPL";
Linux
