@@ -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();
}
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 Signed-off-by: David Hildenbrand <david@redhat.com> --- .../selftests/mm/hugetlb_fault_after_madv.c | 34 ++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-)