Commit f33cea94 authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

selftests/mm: hugetlb_fault_after_madv: improve test output 

Let's improve the test output.  For example, print the proper test result.
Install a SIGBUS handler to catch any SIGBUS instead of crashing the test
on failure.

With unsuitable hugetlb page count:
  $ ./hugetlb_fault_after_madv
  TAP version 13
  1..1
  # [INFO] detected default hugetlb page size: 2048 KiB
  ok 2 # SKIP This test needs one and only one page to execute. Got 0
  # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0

On a failure:
  $ ./hugetlb_fault_after_madv
  TAP version 13
  1..1
  not ok 1 SIGBUS behavior
  Bail out! 1 out of 1 tests failed

On success:
  $ ./hugetlb_fault_after_madv
  TAP version 13
  1..1
  # [INFO] detected default hugetlb page size: 2048 KiB
  ok 1 SIGBUS behavior
  # Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0

Link: https://lkml.kernel.org/r/20240926152044.2205129-3-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarBreno Leitao <leitao@debian.org>
Tested-by: default avatarMario Casquero <mcasquer@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3b2faed0

tools/testing/selftests/mm/hugetlb_fault_after_madv.c

+33 −1
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
#include <sys/mman.h>

#include <sys/types.h>

#include <unistd.h>

#include <setjmp.h>

#include <signal.h>



#include "vm_util.h"

#include "../kselftest.h"
@@ -14,11 +16,25 @@ 
static char *huge_ptr;

static size_t huge_page_size;



static sigjmp_buf sigbuf;

static bool sigbus_triggered;



static void signal_handler(int signal)

{

	if (signal == SIGBUS) {

		sigbus_triggered = true;

		siglongjmp(sigbuf, 1);

	}

}



/* Touch the memory while it is being madvised() */

void *touch(void *unused)

{

	char *ptr = (char *)huge_ptr;



	if (sigsetjmp(sigbuf, 1))

		return NULL;



	for (int i = 0; i < INLOOP_ITER; i++)

		ptr[0] = '.';
@@ -44,13 +60,23 @@ int main(void) 
	 * interactions

	 */

	int max = 10000;

	int err;



	ksft_print_header();

	ksft_set_plan(1);



	srand(getpid());



	if (signal(SIGBUS, signal_handler) == SIG_ERR)

		ksft_exit_skip("Could not register signal handler.");



	huge_page_size = default_huge_page_size();

	if (!huge_page_size)

		ksft_exit_skip("Could not detect default hugetlb page size.");



	ksft_print_msg("[INFO] detected default hugetlb page size: %zu KiB\n",

		       huge_page_size / 1024);



	free_hugepages = get_free_hugepages();

	if (free_hugepages != 1) {

		ksft_exit_skip("This test needs one and only one page to execute. Got %lu\n",
@@ -73,5 +99,11 @@ int main(void) 
		munmap(huge_ptr, huge_page_size);

	}



	return KSFT_PASS;

	ksft_test_result(!sigbus_triggered, "SIGBUS behavior\n");



	err = ksft_get_fail_cnt();

	if (err)

		ksft_exit_fail_msg("%d out of %d tests failed\n",

				   err, ksft_test_num());

	ksft_exit_pass();

}