Date: Wed, 9 Dec 2020 03:20:51 +0000 (UTC) From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r368479 - head/lib/libc/sys Message-ID: <202012090320.0B93KplP045110@repo.freebsd.org>
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Author: kevans Date: Wed Dec 9 03:20:51 2020 New Revision: 368479 URL: https://svnweb.freebsd.org/changeset/base/368479 Log: _umtx_op(2): document recent addition of 32bit compat flags This was part of D27325. Reviewed by: kib Modified: head/lib/libc/sys/_umtx_op.2 Modified: head/lib/libc/sys/_umtx_op.2 ============================================================================== --- head/lib/libc/sys/_umtx_op.2 Wed Dec 9 02:59:24 2020 (r368478) +++ head/lib/libc/sys/_umtx_op.2 Wed Dec 9 03:20:51 2020 (r368479) @@ -28,7 +28,7 @@ .\" .\" $FreeBSD$ .\" -.Dd November 16, 2020 +.Dd November 23, 2020 .Dt _UMTX_OP 2 .Os .Sh NAME @@ -1272,6 +1272,79 @@ See .Sx ROBUST UMUTEXES subsection for details. .El +.Pp +The +.Fa op +argument may be a bitwise OR of a single command from above with one or more of +the following flags: +.Bl -tag -width indent +.It Dv UMTX_OP__I386 +Request i386 ABI compatibility from the native +.Nm +system call. +Specifically, this implies that: +.Bl -hang -offset indent +.It +.Fa obj +arguments that point to a word, point to a 32-bit integer. +.It +The +.Dv UMTX_OP_NWAKE_PRIVATE +.Fa obj +argument is a pointer to an array of 32-bit pointers. +.It +The +.Dv m_rb_lnk +member of +.Vt struct umutex +is a 32-bit pointer. +.It +.Vt struct timespec +uses a 32-bit time_t. +.El +.Pp +.Dv UMTX_OP__32BIT +has no effect if this flag is set. +This flag is valid for all architectures, but it is ignored on i386. +.It Dv UMTX_OP__32BIT +Request non-i386, 32-bit ABI compatibility from the native +.Nm +system call. +Specifically, this implies that: +.Bl -hang -offset indent +.It +.Fa obj +arguments that point to a word, point to a 32-bit integer. +.It +The +.Dv UMTX_OP_NWAKE_PRIVATE +.Fa obj +argument is a pointer to an array of 32-bit pointers. +.It +The +.Dv m_rb_lnk +member of +.Vt struct umutex +is a 32-bit pointer. +.It +.Vt struct timespec +uses a 64-bit time_t. +.El +.Pp +This flag has no effect if +.Dv UMTX_OP__I386 +is set. +This flag is valid for all architectures. +.El +.Pp +Note that if any 32-bit ABI compatibility is being requested, then care must be +taken with robust lists. +A single thread may not mix 32-bit compatible robust lists with native +robust lists. +The first +.Dv UMTX_OP_ROBUST_LISTS +call in a given thread determines which ABI that thread will use for robust +lists going forward. .Sh RETURN VALUES If successful, all requests, except
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