tests/utils/testapp/userspace-probe-sdt-binary/userspace-probe-sdt-binary.c

   1 /*
   2  * Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-or-later
   5  *
   6  */
   7
   8 #ifndef _GNU_SOURCE
   9 #define _GNU_SOURCE
  10 #endif
  11
  12 /*
  13  * The order of inclusion is important here: including sdt.h _before_ the probe
  14  * declarations ensures that semaphore-protected SDT probes (which we don't support) are not
  15  * generated. See SYSTEMTAP(2) for more details.
  16  */
  17 /* clang-format off */
  18 #include <sys/sdt.h>
  19 #include "foobar_provider.h"
  20 /* clang-format on */
  21
  22 #include "libfoo.h"
  23 #include "sema.h"
  24
  25 #include <dlfcn.h>
  26 #include <fcntl.h>
  27 #include <stdbool.h>
  28 #include <stdint.h>
  29 #include <stdio.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32
  33 int main(int argc, char *argv[])
  34 {
  35         void *handle;
  36         void (*bar_function)();
  37
  38         FOOBAR_TP1();
  39         FOOBAR_TP2();
  40         /*
  41          * This SDT tracepoint has an argument. Argument extraction is not supported
  42          * at the moment, but tracing of the tracepoint should work.
  43          */
  44         FOOBAR_TP_WITH_ARG(42);
  45
  46         /* Call a function containing an SDT tracepoint in shared object. */
  47         foo_function();
  48
  49         /*
  50          * Load a shared object and call a function containing an SDT
  51          * tracepoint
  52          */
  53         handle = dlopen("libbar.so", RTLD_LAZY);
  54         if (!handle) {
  55                 fprintf(stderr, "Can't dlopen libbar.so");
  56                 return -1;
  57         }
  58         bar_function = (void (*)()) dlsym(handle, "bar_function");
  59         bar_function();
  60         dlclose(handle);
  61
  62         /* This tracepoint has 2 call sites in this binary. */
  63         FOOBAR_TP2();
  64
  65         /*
  66          * This function is defined in libfoo and in libzzz. For a test, libzzz is
  67          * LD_PRELOADed and should override this function.
  68          */
  69         overridable_function();
  70
  71         /*
  72          * This function is calling a SDT tracepoint that is guarded by a
  73          * semaphore.
  74          */
  75         sema_function();
  76         return 0;
  77 }