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59e8b60bf0
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
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2020, Oracle and/or its affiliates. */
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#include <test_progs.h>
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#include "trace_printk.skel.h"
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#define TRACEBUF "/sys/kernel/debug/tracing/trace_pipe"
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#define SEARCHMSG "testing,testing"
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void test_trace_printk(void)
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{
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int err, iter = 0, duration = 0, found = 0;
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struct trace_printk__bss *bss;
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struct trace_printk *skel;
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char *buf = NULL;
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FILE *fp = NULL;
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size_t buflen;
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skel = trace_printk__open();
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if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
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return;
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err = trace_printk__load(skel);
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if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
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goto cleanup;
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bss = skel->bss;
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err = trace_printk__attach(skel);
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if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
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goto cleanup;
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fp = fopen(TRACEBUF, "r");
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if (CHECK(fp == NULL, "could not open trace buffer",
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"error %d opening %s", errno, TRACEBUF))
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goto cleanup;
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/* We do not want to wait forever if this test fails... */
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fcntl(fileno(fp), F_SETFL, O_NONBLOCK);
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/* wait for tracepoint to trigger */
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usleep(1);
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trace_printk__detach(skel);
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if (CHECK(bss->trace_printk_ran == 0,
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"bpf_trace_printk never ran",
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"ran == %d", bss->trace_printk_ran))
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goto cleanup;
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if (CHECK(bss->trace_printk_ret <= 0,
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"bpf_trace_printk returned <= 0 value",
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"got %d", bss->trace_printk_ret))
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goto cleanup;
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/* verify our search string is in the trace buffer */
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while (getline(&buf, &buflen, fp) >= 0 || errno == EAGAIN) {
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if (strstr(buf, SEARCHMSG) != NULL)
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found++;
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if (found == bss->trace_printk_ran)
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break;
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if (++iter > 1000)
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break;
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}
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if (CHECK(!found, "message from bpf_trace_printk not found",
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"no instance of %s in %s", SEARCHMSG, TRACEBUF))
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goto cleanup;
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cleanup:
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trace_printk__destroy(skel);
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free(buf);
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if (fp)
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fclose(fp);
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}
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