From bdccf0bbace77be605bc53f91c502916034dd31e Mon Sep 17 00:00:00 2001 From: Brandon Bergren Date: Fri, 9 Aug 2019 20:16:38 +0000 Subject: [PATCH] Implement _umtx_op_err.S on powerpc / powerpc64. As per r177853, we need to avoid using errno inside user mutex code, since signal handlers can interfere with it and mess up libthr internal state. So, implement _umtx_op_err() instead, which makes a raw syscall and returns the error value directly instead of using errno. Approved by: jhibbits (mentor) Differential Revision: https://reviews.freebsd.org/D20946 --- lib/libthr/arch/powerpc/Makefile.inc | 3 ++ lib/libthr/arch/powerpc/include/pthread_md.h | 2 + .../arch/powerpc/powerpc/_umtx_op_err.S | 41 +++++++++++++++++++ 3 files changed, 46 insertions(+) create mode 100644 lib/libthr/arch/powerpc/Makefile.inc create mode 100644 lib/libthr/arch/powerpc/powerpc/_umtx_op_err.S diff --git a/lib/libthr/arch/powerpc/Makefile.inc b/lib/libthr/arch/powerpc/Makefile.inc new file mode 100644 index 00000000000..6c0e24fe388 --- /dev/null +++ b/lib/libthr/arch/powerpc/Makefile.inc @@ -0,0 +1,3 @@ +# $FreeBSD$ + +SRCS+= _umtx_op_err.S diff --git a/lib/libthr/arch/powerpc/include/pthread_md.h b/lib/libthr/arch/powerpc/include/pthread_md.h index 939d7d2670e..0ed44058a7a 100644 --- a/lib/libthr/arch/powerpc/include/pthread_md.h +++ b/lib/libthr/arch/powerpc/include/pthread_md.h @@ -91,4 +91,6 @@ _get_curthread(void) return (NULL); } +#define HAS__UMTX_OP_ERR 1 + #endif /* _PTHREAD_MD_H_ */ diff --git a/lib/libthr/arch/powerpc/powerpc/_umtx_op_err.S b/lib/libthr/arch/powerpc/powerpc/_umtx_op_err.S new file mode 100644 index 00000000000..a902a7360d7 --- /dev/null +++ b/lib/libthr/arch/powerpc/powerpc/_umtx_op_err.S @@ -0,0 +1,41 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2019 Brandon Bergren + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include +#include + + .text + .align 2 +ENTRY(_umtx_op_err) + li %r0, SYS__umtx_op + sc + blr +END(_umtx_op_err) + + .section .note.GNU-stack,"",%progbits