[111/127] selftests/vm/pkeys: fix alloc_random_pkey() to make it really random

Commit Message

Andrew Morton June 4, 2020, 11:52 p.m. UTC

From: Ram Pai <[e-mail]>
Subject: selftests/vm/pkeys: fix alloc_random_pkey() to make it really random

alloc_random_pkey() was allocating the same pkey every time.  Not all
pkeys were geting tested.  This fixes it.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ram Pai <[e-mail]>
Signed-off-by: Sandipan Das <[e-mail]>
Acked-by: Dave Hansen <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Florian Weimer <[e-mail]>
Cc: "Desnes A. Nunes do Rosario" <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Thiago Jung Bauermann <[e-mail]>
Cc: "Aneesh Kumar K.V" <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Michal Suchanek <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 tools/testing/selftests/vm/protection_keys.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

--- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-fix-alloc_random_pkey-to-make-it-really-random
+++ a/tools/testing/selftests/vm/protection_keys.c
@@ -25,6 +25,7 @@ 
 #define __SANE_USERSPACE_TYPES__
 #include <errno.h>
 #include <linux/futex.h>
+#include <time.h>
 #include <sys/time.h>
 #include <sys/syscall.h>
 #include <string.h>
@@ -546,10 +547,10 @@  int alloc_random_pkey(void)
 	int nr_alloced = 0;
 	int random_index;
 	memset(alloced_pkeys, 0, sizeof(alloced_pkeys));
+	srand((unsigned int)time(NULL));
 
 	/* allocate every possible key and make a note of which ones we got */
 	max_nr_pkey_allocs = NR_PKEYS;
-	max_nr_pkey_allocs = 1;
 	for (i = 0; i < max_nr_pkey_allocs; i++) {
 		int new_pkey = alloc_pkey();
 		if (new_pkey < 0)