diff options
author | Alan Maguire <alan.maguire@oracle.com> | 2020-07-13 12:52:34 +0100 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-13 16:55:49 -0700 |
commit | 59e8b60bf068180fcadb0ae06ce8f6f835132ce6 (patch) | |
tree | 9add8fdea634ba08ed2a57cae8da34e497eed9e5 /tools/testing | |
parent | ac5a72ea5c8989871e61f6bb0852e0f91de51ebe (diff) | |
download | linux-59e8b60bf068180fcadb0ae06ce8f6f835132ce6.tar.gz linux-59e8b60bf068180fcadb0ae06ce8f6f835132ce6.tar.bz2 linux-59e8b60bf068180fcadb0ae06ce8f6f835132ce6.zip |
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
Diffstat (limited to 'tools/testing')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/trace_printk.c | 75 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/trace_printk.c | 21 |
2 files changed, 96 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/trace_printk.c b/tools/testing/selftests/bpf/prog_tests/trace_printk.c new file mode 100644 index 000000000000..39b0decb1bb2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/trace_printk.c @@ -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); +} diff --git a/tools/testing/selftests/bpf/progs/trace_printk.c b/tools/testing/selftests/bpf/progs/trace_printk.c new file mode 100644 index 000000000000..8ca7f399b670 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/trace_printk.c @@ -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; +} |