From 18c2355838e76788f61849f4d83513b103d68b95 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 22 Nov 2022 15:39:12 -0500 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20221122203932.231377-11-mathieu.desnoyers@efficios.com --- 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 a1faa9162d52..fb4ec8a75dd4 100644 --- a/tools/testing/selftests/rseq/rseq-abi.h +++ b/tools/testing/selftests/rseq/rseq-abi.h @@ -155,6 +155,15 @@ 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. */ diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h index fd17d0e54a1b..10ebf13644fa 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);