mirror of
https://github.com/torvalds/linux.git
synced 2024-12-02 17:11:33 +00:00
selftests/bpf: Add selftests verifying bpf_trace_printk() behaviour
Simple selftests that verifies bpf_trace_printk() returns a sensible value and tracing messages appear. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1594641154-18897-3-git-send-email-alan.maguire@oracle.com
This commit is contained in:
parent
ac5a72ea5c
commit
59e8b60bf0
75
tools/testing/selftests/bpf/prog_tests/trace_printk.c
Normal file
75
tools/testing/selftests/bpf/prog_tests/trace_printk.c
Normal file
@ -0,0 +1,75 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
/* Copyright (c) 2020, Oracle and/or its affiliates. */
|
||||
|
||||
#include <test_progs.h>
|
||||
|
||||
#include "trace_printk.skel.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;
|
||||
|
||||
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);
|
||||
}
|
21
tools/testing/selftests/bpf/progs/trace_printk.c
Normal file
21
tools/testing/selftests/bpf/progs/trace_printk.c
Normal file
@ -0,0 +1,21 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
// Copyright (c) 2020, Oracle and/or its affiliates.
|
||||
|
||||
#include "vmlinux.h"
|
||||
#include <bpf/bpf_helpers.h>
|
||||
#include <bpf/bpf_tracing.h>
|
||||
|
||||
char _license[] SEC("license") = "GPL";
|
||||
|
||||
int trace_printk_ret = 0;
|
||||
int trace_printk_ran = 0;
|
||||
|
||||
SEC("tp/raw_syscalls/sys_enter")
|
||||
int sys_enter(void *ctx)
|
||||
{
|
||||
static const char fmt[] = "testing,testing %d\n";
|
||||
|
||||
trace_printk_ret = bpf_trace_printk(fmt, sizeof(fmt),
|
||||
++trace_printk_ran);
|
||||
return 0;
|
||||
}
|
Loading…
Reference in New Issue
Block a user