This is a note to let you know that I've just added the patch titled
sched/membarrier: Fix membarrier-rseq fence command missing from query bitmask
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sched-membarrier-fix-membarrier-rseq-fence-command-missing-from-query-bitmask.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 809232619f5b15e31fb3563985e705454f32621f Mon Sep 17 00:00:00 2001
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Date: Mon, 17 Jan 2022 15:30:10 -0500
Subject: sched/membarrier: Fix membarrier-rseq fence command missing from query bitmask
From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
commit 809232619f5b15e31fb3563985e705454f32621f upstream.
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@xxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 5.10+
Link: https://lkml.kernel.org/r/20220117203010.30129-1-mathieu.desnoyers@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/sched/membarrier.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- 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)
{
Patches currently in stable-queue which might be from mathieu.desnoyers@xxxxxxxxxxxx are
queue-5.16/sched-membarrier-fix-membarrier-rseq-fence-command-missing-from-query-bitmask.patch
