The following commit has been merged into the sched/urgent branch of tip:

Commit-ID: 809232619f5b15e31fb3563985e705454f32621f Gitweb: https://git.kernel.org/tip/809232619f5b15e31fb3563985e705454f32621f Author: Mathieu Desnoyers mathieu.desnoyers@efficios.com AuthorDate: Mon, 17 Jan 2022 15:30:10 -05:00 Committer: Peter Zijlstra peterz@infradead.org CommitterDate: Tue, 25 Jan 2022 22:30:25 +01:00

sched/membarrier: Fix membarrier-rseq fence command missing from query bitmask

The membarrier command MEMBARRIER_CMD_QUERY allows querying the available membarrier commands. When the membarrier-rseq fence commands were added, a new MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK was introduced with the intent to expose them with the MEMBARRIER_CMD_QUERY command, the but it was never added to MEMBARRIER_CMD_BITMASK.

The membarrier-rseq fence commands are therefore not wired up with the query command.

Rename MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK to MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK (the bitmask is not a command per-se), and change the erroneous MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ_BITMASK (which does not actually exist) to MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ.

Wire up MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK in MEMBARRIER_CMD_BITMASK. Fixing this allows discovering availability of the membarrier-rseq fence feature.

Fixes: 2a36ab717e8f ("rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ") Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: stable@vger.kernel.org # 5.10+ Link: https://lkml.kernel.org/r/20220117203010.30129-1-mathieu.desnoyers@efficios.... --- kernel/sched/membarrier.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index b5add64..3d28254 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -147,11 +147,11 @@ #endif

#ifdef CONFIG_RSEQ -#define MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK \ +#define MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK \ (MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ \ - | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ_BITMASK) + | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ) #else -#define MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK 0 +#define MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK 0 #endif

#define MEMBARRIER_CMD_BITMASK \ @@ -159,7 +159,8 @@ | MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED \ | MEMBARRIER_CMD_PRIVATE_EXPEDITED \ | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED \ - | MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK) + | MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK \ + | MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK)

static void ipi_mb(void *info) {