[PATCH bpf-next v2 7/9] selftests/bpf: Add return value checks for failed tests
From: Xu Kuohai <xukuohai@huaweicloud.com>
Date: 2024-07-19 10:55:55
Also in:
bpf, linux-security-module
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
From: Xu Kuohai <redacted> The return ranges of some bpf lsm test progs can not be deduced by the verifier accurately. To avoid erroneous rejections, add explicit return value checks for these progs. Signed-off-by: Xu Kuohai <redacted> --- tools/testing/selftests/bpf/progs/err.h | 10 ++++++++++ tools/testing/selftests/bpf/progs/test_sig_in_xattr.c | 4 ++++ .../selftests/bpf/progs/test_verify_pkcs7_sig.c | 8 ++++++-- .../selftests/bpf/progs/verifier_global_subprogs.c | 7 ++++++- 4 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/err.h b/tools/testing/selftests/bpf/progs/err.h
index d66d283d9e59..38529779a236 100644
--- a/tools/testing/selftests/bpf/progs/err.h
+++ b/tools/testing/selftests/bpf/progs/err.h@@ -5,6 +5,16 @@ #define MAX_ERRNO 4095 #define IS_ERR_VALUE(x) (unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO +#define __STR(x) #x + +#define set_if_not_errno_or_zero(x, y) \ +({ \ + asm volatile ("if %0 s< -4095 goto +1\n" \ + "if %0 s<= 0 goto +1\n" \ + "%0 = " __STR(y) "\n" \ + : "+r"(x)); \ +}) + static inline int IS_ERR_OR_NULL(const void *ptr) { return !ptr || IS_ERR_VALUE((unsigned long)ptr);
diff --git a/tools/testing/selftests/bpf/progs/test_sig_in_xattr.c b/tools/testing/selftests/bpf/progs/test_sig_in_xattr.c
index 2f0eb1334d65..8ef6b39335b6 100644
--- a/tools/testing/selftests/bpf/progs/test_sig_in_xattr.c
+++ b/tools/testing/selftests/bpf/progs/test_sig_in_xattr.c@@ -6,6 +6,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include "bpf_kfuncs.h" +#include "err.h" char _license[] SEC("license") = "GPL";
@@ -79,5 +80,8 @@ int BPF_PROG(test_file_open, struct file *f) ret = bpf_verify_pkcs7_signature(&digest_ptr, &sig_ptr, trusted_keyring); bpf_key_put(trusted_keyring); + + set_if_not_errno_or_zero(ret, -EFAULT); + return ret; }
diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
index f42e9f3831a1..12034a73ee2d 100644
--- a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
+++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c@@ -11,6 +11,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include "bpf_kfuncs.h" +#include "err.h" #define MAX_DATA_SIZE (1024 * 1024) #define MAX_SIG_SIZE 1024
@@ -55,12 +56,12 @@ int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) ret = bpf_probe_read_kernel(&value, sizeof(value), &attr->value); if (ret) - return ret; + goto out; ret = bpf_copy_from_user(data_val, sizeof(struct data), (void *)(unsigned long)value); if (ret) - return ret; + goto out; if (data_val->data_len > sizeof(data_val->data)) return -EINVAL;
@@ -84,5 +85,8 @@ int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) bpf_key_put(trusted_keyring); +out: + set_if_not_errno_or_zero(ret, -EFAULT); + return ret; }
diff --git a/tools/testing/selftests/bpf/progs/verifier_global_subprogs.c b/tools/testing/selftests/bpf/progs/verifier_global_subprogs.c
index a9fc30ed4d73..20904cd2baa2 100644
--- a/tools/testing/selftests/bpf/progs/verifier_global_subprogs.c
+++ b/tools/testing/selftests/bpf/progs/verifier_global_subprogs.c@@ -7,6 +7,7 @@ #include "bpf_misc.h" #include "xdp_metadata.h" #include "bpf_kfuncs.h" +#include "err.h" /* The compiler may be able to detect the access to uninitialized memory in the routines performing out of bound memory accesses and
@@ -331,7 +332,11 @@ SEC("?lsm/bpf") __success __log_level(2) int BPF_PROG(arg_tag_ctx_lsm) { - return tracing_subprog_void(ctx) + tracing_subprog_u64(ctx); + int ret; + + ret = tracing_subprog_void(ctx) + tracing_subprog_u64(ctx); + set_if_not_errno_or_zero(ret, -1); + return ret; } SEC("?struct_ops/test_1")
--
2.30.2