[PATCH] getrusage: Add smoke test for getrusage

[Adhemerval Zanella Netto]

On 31/08/26 12:48, Ondrej Marek wrote:
> Add smoke test verifying that getrusage returns non-negative user time and fails with invalid who value.
> 
> Co-authored-by: Frantisek Cech <fr.cech@proton.me>
> Signed-off-by: Ondrej Marek <ondrejm4rek@gmail.com>

This version look ok, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  v4:
>  - introduce minor changes based on the review
>  resource/Makefile        |   1 +
>  resource/tst-getrusage.c | 125 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 126 insertions(+)
>  create mode 100644 resource/tst-getrusage.c
> 
> diff --git a/resource/Makefile b/resource/Makefile
> index 589b73f44f..dac48434dd 100644
> --- a/resource/Makefile
> +++ b/resource/Makefile
> @@ -28,6 +28,7 @@ routines := getrlimit setrlimit getrlimit64 setrlimit64 getrusage ulimit      \
>  tests := \
>    bug-ulimit1 \
>    tst-getrlimit \
> +  tst-getrusage \
>  # tests
>  
>  
> diff --git a/resource/tst-getrusage.c b/resource/tst-getrusage.c
> new file mode 100644
> index 0000000000..4caa1bed42
> --- /dev/null
> +++ b/resource/tst-getrusage.c
> @@ -0,0 +1,125 @@
> +/* Test of the getrusage function.
> +   Copyright (C) 2026 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <errno.h>
> +#include <stdio.h>
> +#include <sys/resource.h>
> +#include <stdint.h>
> +#include <support/check.h>
> +#include <sys/types.h>
> +#include <support/xunistd.h>
> +#include <sys/wait.h>
> +#include <benchtests/bench-util.h>
> +#include <array_length.h>
> +
> +static void
> +do_work (void)
> +{
> +  uint64_t sink = 0;
> +  for (uint64_t i = 0; i < UINT64_C (1000000); i++)
> +    {
> +      sink += i;
> +      DO_NOT_OPTIMIZE_OUT (sink);
> +    }
> +}
> +
> +static void
> +get_child_elapsed_time (long *result)
> +{
> +  pid_t pid;
> +  pid = xfork ();
> +
> +  if (pid > 0)
> +    {
> +      int status;
> +      xwaitpid (pid, &status, 0);
> +      TEST_VERIFY_EXIT (WIFEXITED (status));
> +
> +      struct rusage rusage = { 0 };
> +
> +      int ret_val = getrusage (RUSAGE_CHILDREN, &rusage);
> +      TEST_VERIFY_EXIT (ret_val == 0);
> +      long elapsed_time
> +	  = (rusage.ru_utime.tv_sec * 1000000L) + rusage.ru_utime.tv_usec;
> +      TEST_VERIFY_EXIT (elapsed_time >= 0);
> +
> +      *result = elapsed_time;
> +    }
> +  else
> +    {
> +      /* Simulate some work. */
> +      do_work ();
> +      _exit (0);
> +    }
> +}
> +
> +static void
> +test_getrusage_children (void)
> +{
> +  long elapsed_time_before;
> +  long elapsed_time_after;
> +
> +  get_child_elapsed_time (&elapsed_time_before);
> +  get_child_elapsed_time (&elapsed_time_after);
> +  TEST_VERIFY_EXIT (elapsed_time_after >= elapsed_time_before);
> +}
> +
> +static void
> +test_getrusage (int who)
> +{
> +  struct rusage before_usage = { 0 };
> +  struct rusage after_usage = { 0 };
> +
> +  int ret_val = getrusage (who, &before_usage);
> +  TEST_VERIFY_EXIT (ret_val == 0);
> +  long elapsed_time_before = (before_usage.ru_utime.tv_sec * 1000000L)
> +			     + before_usage.ru_utime.tv_usec;
> +  TEST_VERIFY_EXIT (elapsed_time_before >= 0);
> +
> +  /* Simulate some work */
> +  do_work ();
> +
> +  int ret_val2 = getrusage (who, &after_usage);
> +  TEST_VERIFY_EXIT (ret_val2 == 0);
> +
> +  long elapsed_time_after = (after_usage.ru_utime.tv_sec * 1000000L)
> +			    + after_usage.ru_utime.tv_usec;
> +  TEST_VERIFY_EXIT (elapsed_time_after >= elapsed_time_before);
> +}
> +
> +static int
> +do_test (void)
> +{
> +  test_getrusage (RUSAGE_SELF);
> +#ifdef RUSAGE_THREAD
> +  test_getrusage (RUSAGE_THREAD);
> +#endif
> +
> +  /* RUSAGE_CHILDREN test case with forking children */
> +  test_getrusage_children ();
> +
> +  /* Invalid who value test case */
> +  struct rusage usage_struct = { 0 };
> +  int invalid_who = 999;
> +  int ret_val = getrusage (invalid_who, &usage_struct);
> +  TEST_VERIFY (ret_val == -1);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>