Date: Thu, 22 Jul 2021 17:51:58 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: fd5827b1785a - main - man9: Update guarantees for userspace fetch/store operations Message-ID: <202107221751.16MHpw6h045394@gitrepo.freebsd.org>
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The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=fd5827b1785a9363abe601cbd9d8558b0fc8d3e8 commit fd5827b1785a9363abe601cbd9d8558b0fc8d3e8 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2021-07-22 17:08:42 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2021-07-22 17:40:39 +0000 man9: Update guarantees for userspace fetch/store operations Platforms may either silently handle unaligned accesses or return an error. Atomicity is not guaranteed in this case, however. Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D31282 --- share/man/man9/fetch.9 | 8 +++++--- share/man/man9/store.9 | 8 +++++--- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/share/man/man9/fetch.9 b/share/man/man9/fetch.9 index 53927eb82584..16acb542c625 100644 --- a/share/man/man9/fetch.9 +++ b/share/man/man9/fetch.9 @@ -34,7 +34,7 @@ .\" .\" $FreeBSD$ .\" -.Dd January 23, 2020 +.Dd July 22, 2021 .Dt FETCH 9 .Os .Sh NAME @@ -72,8 +72,10 @@ The .Nm functions are designed to copy small amounts of data from user-space of the current process. -If read is successful, it is performed atomically. -The data read must be naturally aligned. +If the user address is naturally aligned, then the operation will be +performed atomically. +Otherwise it may fail or be performed non-atomically, depending on +the platform. .Pp The .Nm diff --git a/share/man/man9/store.9 b/share/man/man9/store.9 index 089949e53938..6492fdbc3924 100644 --- a/share/man/man9/store.9 +++ b/share/man/man9/store.9 @@ -34,7 +34,7 @@ .\" .\" $FreeBSD$ .\" -.Dd April 17, 2018 +.Dd July 22, 2021 .Dt STORE 9 .Os .Sh NAME @@ -60,8 +60,10 @@ The .Nm functions are designed to copy small amounts of data to user-space. -If write is successful, it is performed atomically. -The data written must be naturally aligned. +If the user address is naturally aligned, then the operation will be +performed atomically. +Otherwise it may fail or be performed non-atomically, depending on +the platform. .Pp The .Nm
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