From: Emil Tsalapatis <emil@etsalapatis.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, andrii@kernel.org, memxor@gmail.com,
daniel@iogearbox.net, eddyz87@gmail.com, song@kernel.org,
Emil Tsalapatis <emil@etsalapatis.com>
Subject: [PATCH bpf-next v8 8/8] selftests/bpf: Reuse stderr parsing for libarena ASAN tests
Date: Tue, 21 Apr 2026 12:50:37 -0400 [thread overview]
Message-ID: <20260421165037.4736-9-emil@etsalapatis.com> (raw)
In-Reply-To: <20260421165037.4736-1-emil@etsalapatis.com>
Add code to directly test the output of libarena ASAN tests.
The code reuses testing infrastructure originally for BPF streams
to verify that ASAN emits call stacks when the selftests trigger
a memory error.
Since stderr() testing uses logic from test_progs, it is only
available on the test_progs-based selftest runner. The standalone
runner still uses internal ASAN state to verify access errors are
triaged as expected.
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
---
.../bpf/libarena/include/test_progs_compat.h | 15 ++++++
.../libarena/selftests/st_asan_buddy.bpf.c | 18 +++++++
.../selftests/bpf/prog_tests/libarena_asan.c | 2 +
tools/testing/selftests/bpf/test_loader.c | 51 ++++++++++++++-----
tools/testing/selftests/bpf/test_progs.h | 2 +
5 files changed, 76 insertions(+), 12 deletions(-)
create mode 100644 tools/testing/selftests/bpf/libarena/include/test_progs_compat.h
diff --git a/tools/testing/selftests/bpf/libarena/include/test_progs_compat.h b/tools/testing/selftests/bpf/libarena/include/test_progs_compat.h
new file mode 100644
index 000000000000..9d431376c42f
--- /dev/null
+++ b/tools/testing/selftests/bpf/libarena/include/test_progs_compat.h
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
+/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
+#pragma once
+
+#ifdef __BPF__
+
+/* Selftests use these tags for compatibility with test_progs. */
+#define __test_tag(tag) __attribute__((btf_decl_tag("comment:" XSTR(__COUNTER__) ":" tag)))
+#define __stderr(msg) __test_tag("test_expect_stderr=" msg)
+#define __stderr_unpriv(msg) __test_tag("test_expect_stderr_unpriv=" msg)
+
+#define XSTR(s) STR(s)
+#define STR(s) #s
+
+#endif
diff --git a/tools/testing/selftests/bpf/libarena/selftests/st_asan_buddy.bpf.c b/tools/testing/selftests/bpf/libarena/selftests/st_asan_buddy.bpf.c
index 4b995cce2730..4c1eef263e88 100644
--- a/tools/testing/selftests/bpf/libarena/selftests/st_asan_buddy.bpf.c
+++ b/tools/testing/selftests/bpf/libarena/selftests/st_asan_buddy.bpf.c
@@ -6,6 +6,9 @@
#include <asan.h>
#include <buddy.h>
+/* Required for parsing the ASAN call stacks. */
+#include <test_progs_compat.h>
+
extern buddy_t buddy;
#ifdef BPF_ARENA_ASAN
@@ -142,6 +145,11 @@ static __always_inline int asan_test_buddy_blob_single(void)
}
SEC("syscall")
+__stderr("Memory violation for address {{.*}} for write of size 1")
+__stderr("CPU: {{[0-9]+}} UID: 0 PID: {{[0-9]+}} Comm: {{.*}}")
+__stderr("Call trace:\n"
+"{{([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n"
+"|[ \t]+[^\n]+\n)*}}")
__weak int asan_test_buddy_oob(void)
{
size_t sizes[] = {
@@ -175,6 +183,11 @@ __weak int asan_test_buddy_oob(void)
}
SEC("syscall")
+__stderr("Memory violation for address {{.*}} for write of size 1")
+__stderr("CPU: {{[0-9]+}} UID: 0 PID: {{[0-9]+}} Comm: {{.*}}")
+__stderr("Call trace:\n"
+"{{([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n"
+"|[ \t]+[^\n]+\n)*}}")
__weak int asan_test_buddy_uaf(void)
{
size_t sizes[] = { 16, 32, 64, 128, 256, 512, 1024, 16384 };
@@ -206,6 +219,11 @@ __weak int asan_test_buddy_uaf(void)
}
SEC("syscall")
+__stderr("Memory violation for address {{.*}} for write of size 1")
+__stderr("CPU: {{[0-9]+}} UID: 0 PID: {{[0-9]+}} Comm: {{.*}}")
+__stderr("Call trace:\n"
+"{{([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n"
+"|[ \t]+[^\n]+\n)*}}")
__weak int asan_test_buddy_blob(void)
{
const int iters = 10;
diff --git a/tools/testing/selftests/bpf/prog_tests/libarena_asan.c b/tools/testing/selftests/bpf/prog_tests/libarena_asan.c
index 4e54949b1e3a..46e73cf77540 100644
--- a/tools/testing/selftests/bpf/prog_tests/libarena_asan.c
+++ b/tools/testing/selftests/bpf/prog_tests/libarena_asan.c
@@ -25,6 +25,8 @@ static void run_libarena_asan_test(struct libarena_asan *skel,
ret = libarena_run_prog(bpf_program__fd(prog));
ASSERT_OK(ret, name);
+
+ verify_test_stderr(skel->obj, prog);
}
static void run_test(void)
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index c4c34cae6102..ee637809a1d4 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -93,7 +93,7 @@ void test_loader_fini(struct test_loader *tester)
free(tester->log_buf);
}
-static void free_msgs(struct expected_msgs *msgs)
+void free_msgs(struct expected_msgs *msgs)
{
int i;
@@ -789,6 +789,43 @@ static void emit_stderr(const char *stderr, bool force)
fprintf(stdout, "STDERR:\n=============\n%s=============\n", stderr);
}
+static void verify_stderr(int prog_fd, struct expected_msgs *msgs)
+{
+ LIBBPF_OPTS(bpf_prog_stream_read_opts, ropts);
+ char *buf;
+ int ret;
+
+ if (!msgs->cnt)
+ return;
+
+ buf = malloc(TEST_LOADER_LOG_BUF_SZ);
+ if (!ASSERT_OK_PTR(buf, "malloc"))
+ return;
+
+ ret = bpf_prog_stream_read(prog_fd, 2, buf, TEST_LOADER_LOG_BUF_SZ - 1,
+ &ropts);
+ if (ret > 0) {
+ buf[ret] = '\0';
+ emit_stderr(buf, false);
+ validate_msgs(buf, msgs, emit_stderr);
+ } else {
+ ASSERT_GT(ret, 0, "stderr stream read");
+ }
+
+ free(buf);
+}
+
+void verify_test_stderr(struct bpf_object *obj, struct bpf_program *prog)
+{
+ struct test_spec spec = {};
+
+ if (parse_test_spec(NULL, obj, prog, &spec))
+ return;
+
+ verify_stderr(bpf_program__fd(prog), &spec.priv.stderr);
+ free_test_spec(&spec);
+}
+
static void emit_stdout(const char *bpf_stdout, bool force)
{
if (!force && env.verbosity == VERBOSE_NONE)
@@ -1314,17 +1351,7 @@ void run_subtest(struct test_loader *tester,
goto tobj_cleanup;
}
- if (subspec->stderr.cnt) {
- err = get_stream(2, bpf_program__fd(tprog),
- tester->log_buf, tester->log_buf_sz);
- if (err <= 0) {
- PRINT_FAIL("Unexpected retval from get_stream(): %d, errno = %d\n",
- err, errno);
- goto tobj_cleanup;
- }
- emit_stderr(tester->log_buf, false /*force*/);
- validate_msgs(tester->log_buf, &subspec->stderr, emit_stderr);
- }
+ verify_stderr(bpf_program__fd(tprog), &subspec->stderr);
if (subspec->stdout.cnt) {
err = get_stream(1, bpf_program__fd(tprog),
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 1a44467f4310..37955a8ad385 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -563,5 +563,7 @@ struct expected_msgs {
void validate_msgs(const char *log_buf, struct expected_msgs *msgs,
void (*emit_fn)(const char *buf, bool force));
+void free_msgs(struct expected_msgs *msgs);
+void verify_test_stderr(struct bpf_object *obj, struct bpf_program *prog);
#endif /* __TEST_PROGS_H */
--
2.53.0
next prev parent reply other threads:[~2026-04-21 16:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-21 16:50 [PATCH bpf-next v8 0/8] Introduce arena library and runtime Emil Tsalapatis
2026-04-21 16:50 ` [PATCH bpf-next v8 1/8] selftests/bpf: Add ifdef guard for WRITE_ONCE macro in bpf_atomic.h Emil Tsalapatis
2026-04-21 16:50 ` [PATCH bpf-next v8 2/8] selftests/bpf: Add basic libarena scaffolding Emil Tsalapatis
2026-04-21 20:08 ` sashiko-bot
2026-04-21 16:50 ` [PATCH bpf-next v8 3/8] selftests/bpf: Move arena-related headers into libarena Emil Tsalapatis
2026-04-21 16:50 ` [PATCH bpf-next v8 4/8] selftests/bpf: Add arena ASAN runtime to libarena Emil Tsalapatis
2026-04-21 20:48 ` sashiko-bot
2026-04-21 16:50 ` [PATCH bpf-next v8 5/8] selftests/bpf: Add ASAN support for libarena selftests Emil Tsalapatis
2026-04-21 21:15 ` sashiko-bot
2026-04-21 16:50 ` [PATCH bpf-next v8 6/8] selftests/bpf: Add buddy allocator for libarena Emil Tsalapatis
2026-04-21 17:52 ` bot+bpf-ci
2026-04-21 17:56 ` Emil Tsalapatis
2026-04-21 21:42 ` sashiko-bot
2026-04-21 16:50 ` [PATCH bpf-next v8 7/8] selftests/bpf: Add selftests for libarena buddy allocator Emil Tsalapatis
2026-04-21 21:57 ` sashiko-bot
2026-04-21 16:50 ` Emil Tsalapatis [this message]
2026-04-21 22:16 ` [PATCH bpf-next v8 8/8] selftests/bpf: Reuse stderr parsing for libarena ASAN tests sashiko-bot
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