selftests: bpf: use __stderr in stream error tests

Start using __stderr directly in the bpf programs to test the reporting
of may_goto timeout detection and spin_lock dead lock detection.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250911145808.58042-6-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/stream.c b/tools/testing/selftests/bpf/prog_tests/stream.c
index 9d0e5d93edee739660eaf0fb1cf3a234d330e0de..6f8eac5ccb655571eb173f5a168eeeb978381ef7 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/stream.c
+++ b/tools/testing/selftests/bpf/prog_tests/stream.c
@@ -2,7 +2,6 @@
 /* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
 #include <test_progs.h>
 #include <sys/mman.h>
-#include <regex.h>
 
 #include "stream.skel.h"
 #include "stream_fail.skel.h"
@@ -18,87 +17,6 @@ void test_stream_success(void)
        return;
 }
 
-struct {
-       int prog_off;
-       const char *errstr;
-} stream_error_arr[] = {
-       {
-               offsetof(struct stream, progs.stream_cond_break),
-               "ERROR: Timeout detected for may_goto instruction\n"
-               "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n"
-               "Call trace:\n"
-               "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n"
-               "|[ \t]+[^\n]+\n)*",
-       },
-       {
-               offsetof(struct stream, progs.stream_deadlock),
-               "ERROR: AA or ABBA deadlock detected for bpf_res_spin_lock\n"
-               "Attempted lock   = (0x[0-9a-fA-F]+)\n"
-               "Total held locks = 1\n"
-               "Held lock\\[ 0\\] = \\1\n"  // Lock address must match
-               "CPU: [0-9]+ UID: 0 PID: [0-9]+ Comm: .*\n"
-               "Call trace:\n"
-               "([a-zA-Z_][a-zA-Z0-9_]*\\+0x[0-9a-fA-F]+/0x[0-9a-fA-F]+\n"
-               "|[ \t]+[^\n]+\n)*",
-       },
-};
-
-static int match_regex(const char *pattern, const char *string)
-{
-       int err, rc;
-       regex_t re;
-
-       err = regcomp(&re, pattern, REG_EXTENDED | REG_NEWLINE);
-       if (err)
-               return -1;
-       rc = regexec(&re, string, 0, NULL, 0);
-       regfree(&re);
-       return rc == 0 ? 1 : 0;
-}
-
-void test_stream_errors(void)
-{
-       LIBBPF_OPTS(bpf_test_run_opts, opts);
-       LIBBPF_OPTS(bpf_prog_stream_read_opts, ropts);
-       struct stream *skel;
-       int ret, prog_fd;
-       char buf[1024];
-
-       skel = stream__open_and_load();
-       if (!ASSERT_OK_PTR(skel, "stream__open_and_load"))
-               return;
-
-       for (int i = 0; i < ARRAY_SIZE(stream_error_arr); i++) {
-               struct bpf_program **prog;
-
-               prog = (struct bpf_program **)(((char *)skel) + stream_error_arr[i].prog_off);
-               prog_fd = bpf_program__fd(*prog);
-               ret = bpf_prog_test_run_opts(prog_fd, &opts);
-               ASSERT_OK(ret, "ret");
-               ASSERT_OK(opts.retval, "retval");
-
-#if !defined(__x86_64__) && !defined(__s390x__) && !defined(__aarch64__)
-               ASSERT_TRUE(1, "Timed may_goto unsupported, skip.");
-               if (i == 0) {
-                       ret = bpf_prog_stream_read(prog_fd, 2, buf, sizeof(buf), &ropts);
-                       ASSERT_EQ(ret, 0, "stream read");
-                       continue;
-               }
-#endif
-
-               ret = bpf_prog_stream_read(prog_fd, BPF_STREAM_STDERR, buf, sizeof(buf), &ropts);
-               ASSERT_GT(ret, 0, "stream read");
-               ASSERT_LE(ret, 1023, "len for buf");
-               buf[ret] = '\0';
-
-               ret = match_regex(stream_error_arr[i].errstr, buf);
-               if (!ASSERT_TRUE(ret == 1, "regex match"))
-                       fprintf(stderr, "Output from stream:\n%s\n", buf);
-       }
-
-       stream__destroy(skel);
-}
-
 void test_stream_syscall(void)
 {
        LIBBPF_OPTS(bpf_test_run_opts, opts);

diff --git a/tools/testing/selftests/bpf/progs/stream.c b/tools/testing/selftests/bpf/progs/stream.c
index 35790897dc879ed916eb7ba675e24a55ee794db8..bb465dad824700d3bfc9504d677027f913f20b87 100644 (file)
--- a/tools/testing/selftests/bpf/progs/stream.c
+++ b/tools/testing/selftests/bpf/progs/stream.c
@@ -37,7 +37,15 @@ int stream_exhaust(void *ctx)
 }
 
 SEC("syscall")
+__arch_x86_64
+__arch_arm64
+__arch_s390x
 __success __retval(0)
+__stderr("ERROR: Timeout detected for may_goto instruction")
+__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)*}}")
 int stream_cond_break(void *ctx)
 {
        while (can_loop)
@@ -47,6 +55,15 @@ int stream_cond_break(void *ctx)
 
 SEC("syscall")
 __success __retval(0)
+__stderr("ERROR: AA or ABBA deadlock detected for bpf_res_spin_lock")
+__stderr("{{Attempted lock   = (0x[0-9a-fA-F]+)\n"
+"Total held locks = 1\n"
+"Held lock\\[ 0\\] = \\1}}")
+__stderr("...")
+__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)*}}")
 int stream_deadlock(void *ctx)
 {
        struct bpf_res_spin_lock *lock, *nlock;