From: Ram Pai <linuxram@xxxxxxxxxx> 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/0162f55816d4e783a0d6e49e554d0ab9a3c9a23b.1585646528.git.sandipan@xxxxxxxxxxxxx Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx> Signed-off-by: Sandipan Das <sandipan@xxxxxxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Florian Weimer <fweimer@xxxxxxxxxx> Cc: "Desnes A. Nunes do Rosario" <desnesn@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Michal Suchanek <msuchanek@xxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/protection_keys.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- 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) _