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@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-11-mathieu.desnoyers@efficios.com
This commit is contained in:
Mathieu Desnoyers 2022-11-22 15:39:12 -05:00 committed by Peter Zijlstra
parent 72cb1d7f2f
commit 18c2355838
2 changed files with 19 additions and 0 deletions

View File

@ -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.
*/

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@ -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);