kernel/tools/testing/selftests/bpf/prog_tests/trace_printk.c
2024-07-22 17:22:30 +08:00

79 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020, Oracle and/or its affiliates. */
#include <test_progs.h>
#include "trace_printk.lskel.h"
#define TRACEBUF "/sys/kernel/debug/tracing/trace_pipe"
#define SEARCHMSG "testing,testing"
void test_trace_printk(void)
{
int err, iter = 0, duration = 0, found = 0;
struct trace_printk__bss *bss;
struct trace_printk *skel;
char *buf = NULL;
FILE *fp = NULL;
size_t buflen;
skel = trace_printk__open();
if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
return;
ASSERT_EQ(skel->rodata->fmt[0], 'T', "invalid printk fmt string");
skel->rodata->fmt[0] = 't';
err = trace_printk__load(skel);
if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
goto cleanup;
bss = skel->bss;
err = trace_printk__attach(skel);
if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
goto cleanup;
fp = fopen(TRACEBUF, "r");
if (CHECK(fp == NULL, "could not open trace buffer",
"error %d opening %s", errno, TRACEBUF))
goto cleanup;
/* We do not want to wait forever if this test fails... */
fcntl(fileno(fp), F_SETFL, O_NONBLOCK);
/* wait for tracepoint to trigger */
usleep(1);
trace_printk__detach(skel);
if (CHECK(bss->trace_printk_ran == 0,
"bpf_trace_printk never ran",
"ran == %d", bss->trace_printk_ran))
goto cleanup;
if (CHECK(bss->trace_printk_ret <= 0,
"bpf_trace_printk returned <= 0 value",
"got %d", bss->trace_printk_ret))
goto cleanup;
/* verify our search string is in the trace buffer */
while (getline(&buf, &buflen, fp) >= 0 || errno == EAGAIN) {
if (strstr(buf, SEARCHMSG) != NULL)
found++;
if (found == bss->trace_printk_ran)
break;
if (++iter > 1000)
break;
}
if (CHECK(!found, "message from bpf_trace_printk not found",
"no instance of %s in %s", SEARCHMSG, TRACEBUF))
goto cleanup;
cleanup:
trace_printk__destroy(skel);
free(buf);
if (fp)
fclose(fp);
}