selftests/bpf: test cases for compute_live_registers()

Cover instructions from each kind:
- assignment
- arithmetic
- store/load
- endian conversion
- atomics
- branches, conditional branches, may_goto, calls
- LD_ABS/LD_IND
- address_space_cast

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250304195024.2478889-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c b/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c
new file mode 100644 (file)
index 0000000..285f202
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/compute_live_registers.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "compute_live_registers.skel.h"
+#include "test_progs.h"
+
+void test_compute_live_registers(void)
+{
+       RUN_TESTS(compute_live_registers);
+}

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 34f555da546fb01a9f7a3a18c0c8cf87d4082b09..13a2e22f546583ce7cdb6f2d6c71d682e5c2ecc6 100644 (file)
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -213,4 +213,21 @@
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 #endif
 
+#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) ||     \
+     (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) ||           \
+     defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) ||      \
+     defined(__TARGET_ARCH_loongarch)) &&                              \
+       __clang_major__ >= 18
+#define CAN_USE_GOTOL
+#endif
+
+#if _clang_major__ >= 18
+#define CAN_USE_BPF_ST
+#endif
+
+#if __clang_major__ >= 18 && defined(ENABLE_ATOMICS_TESTS) && \
+       (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
+#define CAN_USE_LOAD_ACQ_STORE_REL
+#endif
+
 #endif

diff --git a/tools/testing/selftests/bpf/progs/compute_live_registers.c b/tools/testing/selftests/bpf/progs/compute_live_registers.c
new file mode 100644 (file)
index 0000000..14df929
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/compute_live_registers.c
@@ -0,0 +1,424 @@
+// 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);
+}
+
+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: 0......... (b7) r1 = 1")
+__msg("1: 01........ (e5) may_goto pc+1")
+__msg("2: 0......... (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);
+}
+
+/* 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";

diff --git a/tools/testing/selftests/bpf/progs/verifier_gotol.c b/tools/testing/selftests/bpf/progs/verifier_gotol.c
index 05a329ee45ee95c10b8a37db13e7794c1df38fdd..d5d8f24df3949318cab1083de56abf19984c3584 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_gotol.c
+++ b/tools/testing/selftests/bpf/progs/verifier_gotol.c
@@ -4,11 +4,7 @@
 #include <bpf/bpf_helpers.h>
 #include "bpf_misc.h"
 
-#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-       (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
-       defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
-       defined(__TARGET_ARCH_loongarch)) && \
-       __clang_major__ >= 18
+#ifdef CAN_USE_GOTOL
 
 SEC("socket")
 __description("gotol, small_imm")

diff --git a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
index e54bb5385bc1b4d64fb22466485879e0a8f2d75b..75dd922e4e9f87ebc947ee6e621a789cad10431e 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
+++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
@@ -407,11 +407,7 @@ l0_%=:     call %[bpf_jiffies64];          \
        : __clobber_all);
 }
 
-#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \
-       (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \
-       defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390) || \
-       defined(__TARGET_ARCH_loongarch)) && \
-       __clang_major__ >= 18
+#ifdef CAN_USE_GOTOL
 SEC("socket")
 __success __retval(0)
 __naked void gotol_and_may_goto(void)

diff --git a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
index ff308f24d7450ae8b6aa984b79a357b0600c3cd6..608097453832709f439d13e73fdfbc0d0674be27 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
+++ b/tools/testing/selftests/bpf/progs/verifier_load_acquire.c
@@ -6,8 +6,7 @@
 #include "../../../include/linux/filter.h"
 #include "bpf_misc.h"
 
-#if __clang_major__ >= 18 && defined(ENABLE_ATOMICS_TESTS) && \
-       (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
+#ifdef CAN_USE_LOAD_ACQ_STORE_REL
 
 SEC("socket")
 __description("load-acquire, 8-bit")
@@ -182,7 +181,7 @@ __naked void load_acquire_from_sock_pointer(void)
        : __clobber_all);
 }
 
-#else
+#else /* CAN_USE_LOAD_ACQ_STORE_REL */
 
 SEC("socket")
 __description("Clang version < 18, ENABLE_ATOMICS_TESTS not defined, and/or JIT doesn't support load-acquire, use a dummy test")
@@ -192,6 +191,6 @@ int dummy_test(void)
        return 0;
 }
 
-#endif
+#endif /* CAN_USE_LOAD_ACQ_STORE_REL */
 
 char _license[] SEC("license") = "GPL";