Makes membarrier_test compatible with older kernels (LTS) by checking if the membarrier features exist before running the tests.

Link: https://bugs.linaro.org/show_bug.cgi?id=3771 Signed-off-by: Rafael David Tinoco rafael.tinoco@linaro.org Cc: stable@vger.kernel.org #v4.17 --- .../selftests/membarrier/membarrier_test.c | 69 +++++++++++-------- 1 file changed, 41 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/membarrier/membarrier_test.c b/tools/testing/selftests/membarrier/membarrier_test.c index 6793f8ecc8e7..b96caa096e2f 100644 --- a/tools/testing/selftests/membarrier/membarrier_test.c +++ b/tools/testing/selftests/membarrier/membarrier_test.c @@ -225,7 +225,14 @@ static int test_membarrier_global_expedited_success(void)

static int test_membarrier(void) { - int status; + int supported, status; + + supported = sys_membarrier(MEMBARRIER_CMD_QUERY, 0); + if (supported < 0) { + ksft_test_result_fail( + "sys_membarrier() failed to query supported cmds\n"); + return supported; + }

status = test_membarrier_cmd_fail(); if (status) @@ -236,21 +243,22 @@ static int test_membarrier(void) status = test_membarrier_global_success(); if (status) return status; - status = test_membarrier_private_expedited_fail(); - if (status) - return status; - status = test_membarrier_register_private_expedited_success(); - if (status) - return status; - status = test_membarrier_private_expedited_success(); - if (status) - return status; - status = sys_membarrier(MEMBARRIER_CMD_QUERY, 0); - if (status < 0) { - ksft_test_result_fail("sys_membarrier() failed\n"); - return status; + + /* commit 22e4ebb975822833b083533035233d128b30e98f added this feature */ + if (supported & MEMBARRIER_CMD_PRIVATE_EXPEDITED) { + status = test_membarrier_private_expedited_fail(); + if (status) + return status; + status = test_membarrier_register_private_expedited_success(); + if (status) + return status; + status = test_membarrier_private_expedited_success(); + if (status) + return status; } - if (status & MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE) { + + /* commit 70216e18e519a54a2f13569e8caff99a092a92d6 added this feature */ + if (supported & MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE) { status = test_membarrier_private_expedited_sync_core_fail(); if (status) return status; @@ -261,19 +269,24 @@ static int test_membarrier(void) if (status) return status; } - /* - * It is valid to send a global membarrier from a non-registered - * process. - */ - status = test_membarrier_global_expedited_success(); - if (status) - return status; - status = test_membarrier_register_global_expedited_success(); - if (status) - return status; - status = test_membarrier_global_expedited_success(); - if (status) - return status; + + /* commit c5f58bd58f432be5d92df33c5458e0bcbee3aadf added this feature */ + if (supported & MEMBARRIER_CMD_GLOBAL_EXPEDITED) { + /* + * It is valid to send a global membarrier from a non-registered + * process. + */ + status = test_membarrier_global_expedited_success(); + if (status) + return status; + status = test_membarrier_register_global_expedited_success(); + if (status) + return status; + status = test_membarrier_global_expedited_success(); + if (status) + return status; + } + return 0; }