Date: Wed, 2 Dec 2015 10:23:54 +0000 (UTC) From: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= <royger@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r291644 - stable/10/sys/x86/x86 Message-ID: <201512021023.tB2ANstv032634@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: royger Date: Wed Dec 2 10:23:54 2015 New Revision: 291644 URL: https://svnweb.freebsd.org/changeset/base/291644 Log: MFC r291022: x86/intr: allow mutex recursion in intr_remove_handler Sponsored by: Citrix Systems R&D Modified: stable/10/sys/x86/x86/intr_machdep.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/x86/x86/intr_machdep.c ============================================================================== --- stable/10/sys/x86/x86/intr_machdep.c Wed Dec 2 08:17:31 2015 (r291643) +++ stable/10/sys/x86/x86/intr_machdep.c Wed Dec 2 10:23:54 2015 (r291644) @@ -197,19 +197,28 @@ int intr_remove_handler(void *cookie) { struct intsrc *isrc; - int error; + int error, mtx_owned; isrc = intr_handler_source(cookie); error = intr_event_remove_handler(cookie); if (error == 0) { - mtx_lock(&intr_table_lock); + /* + * Recursion is needed here so PICs can remove interrupts + * while resuming. It was previously not possible due to + * intr_resume holding the intr_table_lock and + * intr_remove_handler recursing on it. + */ + mtx_owned = mtx_owned(&intr_table_lock); + if (mtx_owned == 0) + mtx_lock(&intr_table_lock); isrc->is_handlers--; if (isrc->is_handlers == 0) { isrc->is_pic->pic_disable_source(isrc, PIC_NO_EOI); isrc->is_pic->pic_disable_intr(isrc); } intrcnt_updatename(isrc); - mtx_unlock(&intr_table_lock); + if (mtx_owned == 0) + mtx_unlock(&intr_table_lock); } return (error); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201512021023.tB2ANstv032634>