From: Alexei Starovoitov Add few tests for topo sort: - linear chain: main -> A -> B - diamond: main -> A, main -> B, A -> C, B -> C - mixed global/static: main -> global -> static leaf - shared callee: main -> leaf, main -> global -> leaf - duplicate calls: main calls same subprog twice - no calls: single subprog Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/prog_tests/verifier.c | 2 + .../bpf/progs/verifier_subprog_topo.c | 226 ++++++++++++++++++ 2 files changed, 228 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_subprog_topo.c diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index bcf01cb4cfe4..1ac366fd4dae 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -93,6 +93,7 @@ #include "verifier_stack_ptr.skel.h" #include "verifier_store_release.skel.h" #include "verifier_subprog_precision.skel.h" +#include "verifier_subprog_topo.skel.h" #include "verifier_subreg.skel.h" #include "verifier_tailcall.skel.h" #include "verifier_tailcall_jit.skel.h" @@ -238,6 +239,7 @@ void test_verifier_spin_lock(void) { RUN(verifier_spin_lock); } void test_verifier_stack_ptr(void) { RUN(verifier_stack_ptr); } void test_verifier_store_release(void) { RUN(verifier_store_release); } void test_verifier_subprog_precision(void) { RUN(verifier_subprog_precision); } +void test_verifier_subprog_topo(void) { RUN(verifier_subprog_topo); } void test_verifier_subreg(void) { RUN(verifier_subreg); } void test_verifier_tailcall(void) { RUN(verifier_tailcall); } void test_verifier_tailcall_jit(void) { RUN(verifier_tailcall_jit); } diff --git a/tools/testing/selftests/bpf/progs/verifier_subprog_topo.c b/tools/testing/selftests/bpf/progs/verifier_subprog_topo.c new file mode 100644 index 000000000000..e2b9d14bbc3d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_subprog_topo.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "bpf_misc.h" + +/* linear chain main -> A -> B */ +__naked __noinline __used +static unsigned long linear_b(void) +{ + asm volatile ( + "r0 = 42;" + "exit;" + ); +} + +__naked __noinline __used +static unsigned long linear_a(void) +{ + asm volatile ( + "call linear_b;" + "exit;" + ); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = linear_b") +__msg("topo_order[1] = linear_a") +__msg("topo_order[2] = topo_linear") +__naked int topo_linear(void) +{ + asm volatile ( + "call linear_a;" + "exit;" + ); +} + +/* diamond main -> A, main -> B, A -> C, B -> C */ +__naked __noinline __used +static unsigned long diamond_c(void) +{ + asm volatile ( + "r0 = 1;" + "exit;" + ); +} + +__naked __noinline __used +static unsigned long diamond_b(void) +{ + asm volatile ( + "call diamond_c;" + "exit;" + ); +} + +__naked __noinline __used +static unsigned long diamond_a(void) +{ + asm volatile ( + "call diamond_c;" + "exit;" + ); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = diamond_c") +__msg("topo_order[3] = topo_diamond") +__naked int topo_diamond(void) +{ + asm volatile ( + "call diamond_a;" + "call diamond_b;" + "exit;" + ); +} + +/* main -> global_a (global) -> static_leaf (static, leaf) */ +__naked __noinline __used +static unsigned long static_leaf(void) +{ + asm volatile ( + "r0 = 7;" + "exit;" + ); +} + +__noinline __used +int global_a(int x) +{ + return static_leaf(); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = static_leaf") +__msg("topo_order[1] = global_a") +__msg("topo_order[2] = topo_mixed") +__naked int topo_mixed(void) +{ + asm volatile ( + "r1 = 0;" + "call global_a;" + "exit;" + ); +} + +/* + * shared static callee from global and main: + * main -> shared_leaf (static) + * main -> global_b (global) -> shared_leaf (static) + */ +__naked __noinline __used +static unsigned long shared_leaf(void) +{ + asm volatile ( + "r0 = 99;" + "exit;" + ); +} + +__noinline __used +int global_b(int x) +{ + return shared_leaf(); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = shared_leaf") +__msg("topo_order[1] = global_b") +__msg("topo_order[2] = topo_shared") +__naked int topo_shared(void) +{ + asm volatile ( + "call shared_leaf;" + "r1 = 0;" + "call global_b;" + "exit;" + ); +} + +/* duplicate calls to the same subprog */ +__naked __noinline __used +static unsigned long dup_leaf(void) +{ + asm volatile ( + "r0 = 0;" + "exit;" + ); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = dup_leaf") +__msg("topo_order[1] = topo_dup_calls") +__naked int topo_dup_calls(void) +{ + asm volatile ( + "call dup_leaf;" + "call dup_leaf;" + "exit;" + ); +} + +/* main calls bpf_loop() with loop_cb as the callback */ +static int loop_cb(int idx, void *ctx) +{ + return 0; +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = loop_cb") +__msg("topo_order[1] = topo_loop_cb") +int topo_loop_cb(void) +{ + bpf_loop(1, loop_cb, NULL, 0); + return 0; +} + +/* + * bpf_loop callback calling another subprog + * main -> bpf_loop(callback=loop_cb2) -> loop_cb2 -> loop_cb2_leaf + */ +__naked __noinline __used +static unsigned long loop_cb2_leaf(void) +{ + asm volatile ( + "r0 = 0;" + "exit;" + ); +} + +static int loop_cb2(int idx, void *ctx) +{ + return loop_cb2_leaf(); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = loop_cb2_leaf") +__msg("topo_order[1] = loop_cb2") +__msg("topo_order[2] = topo_loop_cb_chain") +int topo_loop_cb_chain(void) +{ + bpf_loop(1, loop_cb2, NULL, 0); + return 0; +} + +/* no calls (single subprog) */ +SEC("?raw_tp") +__success __log_level(2) +__msg("topo_order[0] = topo_no_calls") +__naked int topo_no_calls(void) +{ + asm volatile ( + "r0 = 0;" + "exit;" + ); +} + +char _license[] SEC("license") = "GPL"; -- 2.52.0