Re: [PATCH for 5.5 1/2] rseq: Fix: Clarify rseq.h UAPI rseq_cs memory reclaim requirements
flat view
From: Florian Weimer <hidden>
Date: 2019-12-20 20:38:53
Also in:
lkml, stable
* Mathieu Desnoyers:
quoted hunk
diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h index 9a402fdb60e9..6f26b0b148a6 100644 --- a/include/uapi/linux/rseq.h +++ b/include/uapi/linux/rseq.h@@ -100,7 +100,9 @@ struct rseq { * instruction sequence block, as well as when the kernel detects that * it is preempting or delivering a signal outside of the range * targeted by the rseq_cs. Also needs to be set to NULL by user-space - * before reclaiming memory that contains the targeted struct rseq_cs. + * before reclaiming memory that contains the targeted struct rseq_cs + * or reclaiming memory that contains the code refered to by the + * start_ip and post_commit_offset fields of struct rseq_cs.
Maybe mention that it's good practice to clear rseq_cs before returning from a function that contains a restartable sequence? That will deal with the dlclose issue because even if the function calls dlclose itself, unmapping something on call stack for dlclose is already undefined.