[PATCH bpf-next v6 2/2] selftests/bpf: Add trampolines single and multi-level pointer params test coverage
From: Slava Imameev <hidden>
Date: 2026-03-14 08:22:37
Also in:
bpf, linux-kselftest, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add single and multi-level pointer parameters and return value test coverage for BPF trampolines. Includes verifier tests for single and multi-level pointers. The tests check verifier logs for pointers inferred as scalar() type. Signed-off-by: Slava Imameev <redacted> --- net/bpf/test_run.c | 17 +++++ .../selftests/bpf/prog_tests/verifier.c | 2 + .../bpf/progs/verifier_ctx_ptr_param.c | 68 +++++++++++++++++++ 3 files changed, 87 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_ctx_ptr_param.c
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 56bc8dc1e281..14c4814a7dab 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c@@ -567,6 +567,23 @@ noinline void bpf_fentry_test_sinfo(struct skb_shared_info *sinfo) { } +noinline void bpf_fentry_test_ppvoid(void **pp) +{ +} + +noinline void bpf_fentry_test_pppvoid(void ***ppp) +{ +} + +noinline void bpf_fentry_test_ppfile(struct file **ppf) +{ +} + +noinline struct file **bpf_fexit_test_ret_ppfile(void) +{ + return (struct file **)NULL; +} + __bpf_kfunc int bpf_modify_return_test(int a, int *b) { *b += 1;
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 8cdfd74c95d7..bcf01cb4cfe4 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c@@ -115,6 +115,7 @@ #include "verifier_lsm.skel.h" #include "verifier_jit_inline.skel.h" #include "irq.skel.h" +#include "verifier_ctx_ptr_param.skel.h" #define MAX_ENTRIES 11
@@ -259,6 +260,7 @@ void test_verifier_lsm(void) { RUN(verifier_lsm); } void test_irq(void) { RUN(irq); } void test_verifier_mtu(void) { RUN(verifier_mtu); } void test_verifier_jit_inline(void) { RUN(verifier_jit_inline); } +void test_verifier_ctx_ptr_param(void) { RUN(verifier_ctx_ptr_param); } static int init_test_val_map(struct bpf_object *obj, char *map_name) {
diff --git a/tools/testing/selftests/bpf/progs/verifier_ctx_ptr_param.c b/tools/testing/selftests/bpf/progs/verifier_ctx_ptr_param.c
new file mode 100644
index 000000000000..d5cc8fc01fe6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_ctx_ptr_param.c@@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Verifier tests for single- and multi-level pointer parameter handling + * Copyright (c) 2026 CrowdStrike, Inc. + */ + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "bpf_misc.h" + +SEC("fentry/bpf_fentry_test_ppvoid") +__description("fentry/void**: void ** inferred as scalar") +__success __retval(0) +__log_level(2) +__msg("R1=ctx() R2=scalar()") +__naked void fentry_ppvoid_as_scalar(void) +{ + asm volatile (" \ + r2 = *(u64 *)(r1 + 0); \ + r0 = 0; \ + exit; \ + " ::: __clobber_all); +} + +SEC("fentry/bpf_fentry_test_pppvoid") +__description("fentry/void***: void *** inferred as scalar") +__success __retval(0) +__log_level(2) +__msg("R1=ctx() R2=scalar()") +__naked void fentry_pppvoid_as_scalar(void) +{ + asm volatile (" \ + r2 = *(u64 *)(r1 + 0); \ + r0 = 0; \ + exit; \ + " ::: __clobber_all); +} + +SEC("fentry/bpf_fentry_test_ppfile") +__description("fentry/struct file**: struct file ** inferred as scalar") +__success __retval(0) +__log_level(2) +__msg("R1=ctx() R2=scalar()") +__naked void fentry_ppfile_as_scalar(void) +{ + asm volatile (" \ + r2 = *(u64 *)(r1 + 0); \ + r0 = 0; \ + exit; \ + " ::: __clobber_all); +} + +SEC("fexit/bpf_fexit_test_ret_ppfile") +__description("fexit/return struct file**: returned struct file ** inferred as scalar") +__success __retval(0) +__log_level(2) +__msg("R1=ctx() R2=scalar()") +__naked void fexit_ppfile_as_scalar(void) +{ + asm volatile (" \ + r2 = *(u64 *)(r1 + 0); \ + r0 = 0; \ + exit; \ + " ::: __clobber_all); +} + +char _license[] SEC("license") = "GPL";
--
2.34.1