Date: Mon, 3 Oct 2011 17:01:31 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r225943 - in head/sys: amd64/amd64 i386/i386 Message-ID: <201110031701.p93H1VXn019826@svn.freebsd.org>
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Author: kib Date: Mon Oct 3 17:01:31 2011 New Revision: 225943 URL: http://svn.freebsd.org/changeset/base/225943 Log: Do not allow the kernel to access usermode pages without installed fault handler. Panic immediately in such situation, on i386 and amd64. Reviewed by: avg, jhb MFC after: 1 week Modified: head/sys/amd64/amd64/trap.c head/sys/i386/i386/trap.c Modified: head/sys/amd64/amd64/trap.c ============================================================================== --- head/sys/amd64/amd64/trap.c Mon Oct 3 16:58:58 2011 (r225942) +++ head/sys/amd64/amd64/trap.c Mon Oct 3 17:01:31 2011 (r225943) @@ -674,6 +674,19 @@ trap_pfault(frame, usermode) goto nogo; map = &vm->vm_map; + + /* + * When accessing a usermode address, kernel must be + * ready to accept the page fault, and provide a + * handling routine. Since accessing the address + * without the handler is a bug, do not try to handle + * it normally, and panic immediately. + */ + if (!usermode && (td->td_intr_nesting_level != 0 || + PCPU_GET(curpcb)->pcb_onfault == NULL)) { + trap_fatal(frame, eva); + return (-1); + } } /* Modified: head/sys/i386/i386/trap.c ============================================================================== --- head/sys/i386/i386/trap.c Mon Oct 3 16:58:58 2011 (r225942) +++ head/sys/i386/i386/trap.c Mon Oct 3 17:01:31 2011 (r225943) @@ -831,6 +831,11 @@ trap_pfault(frame, usermode, eva) goto nogo; map = &vm->vm_map; + if (!usermode && (td->td_intr_nesting_level != 0 || + PCPU_GET(curpcb)->pcb_onfault == NULL)) { + trap_fatal(frame, eva); + return (-1); + } } /*
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