The following commit has been merged into the sched/core branch of tip:
Commit-ID: 18c2355838e76788f61849f4d83513b103d68b95
Gitweb: https://git.kernel.org/tip/18c2355838e76788f61849f4d83513b103d68b95
Author: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
AuthorDate: Tue, 22 Nov 2022 15:39:12 -05:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 27 Dec 2022 12:52:12 +01:00
selftests/rseq: Implement rseq mm_cid field support
Add support for the mm_cid field (per-memory-map concurrency ID) of
struct rseq to rseq selftests.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221122203932.231377-11-mathieu.desnoyers@xxxxxxxxxxxx
---
tools/testing/selftests/rseq/rseq-abi.h | 9 +++++++++
tools/testing/selftests/rseq/rseq.h | 10 ++++++++++
2 files changed, 19 insertions(+)
diff --git a/tools/testing/selftests/rseq/rseq-abi.h b/tools/testing/selftests/rseq/rseq-abi.h
index a1faa91..fb4ec8a 100644
--- a/tools/testing/selftests/rseq/rseq-abi.h
+++ b/tools/testing/selftests/rseq/rseq-abi.h
@@ -156,6 +156,15 @@ struct rseq_abi {
__u32 node_id;
/*
+ * Restartable sequences mm_cid field. Updated by the kernel. Read by
+ * user-space with single-copy atomicity semantics. This field should
+ * only be read by the thread which registered this data structure.
+ * Aligned on 32-bit. Contains the current thread's concurrency ID
+ * (allocated uniquely within a memory map).
+ */
+ __u32 mm_cid;
+
+ /*
* Flexible array member at end of structure, after last feature field.
*/
char end[];
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index fd17d0e..10ebf13 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -191,6 +191,16 @@ static inline uint32_t rseq_current_node_id(void)
return RSEQ_ACCESS_ONCE(rseq_get_abi()->node_id);
}
+static inline bool rseq_mm_cid_available(void)
+{
+ return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, mm_cid);
+}
+
+static inline uint32_t rseq_current_mm_cid(void)
+{
+ return RSEQ_ACCESS_ONCE(rseq_get_abi()->mm_cid);
+}
+
static inline void rseq_clear_rseq_cs(void)
{
RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);
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