Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751156AbWEaUPo (ORCPT ); Wed, 31 May 2006 16:15:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751292AbWEaUPo (ORCPT ); Wed, 31 May 2006 16:15:44 -0400 Received: from mailout1.vmware.com ([65.113.40.130]:20943 "EHLO mailout1.vmware.com") by vger.kernel.org with ESMTP id S1751156AbWEaUPn (ORCPT ); Wed, 31 May 2006 16:15:43 -0400 Message-ID: <447DF96E.4000602@vmware.com> Date: Wed, 31 May 2006 13:15:42 -0700 From: Zachary Amsden User-Agent: Thunderbird 1.5.0.2 (X11/20060420) MIME-Version: 1.0 To: akpm@osdl.org Cc: 76306.1226@compuserve.com, ak@muc.de, rohitseth@google.com, Linux Kernel Mailing List Subject: Re: + i386-fix-get_segment_eip-with-vm86.patch added to -mm tree References: <200605300302.k4U321t6026244@shell0.pdx.osdl.net> In-Reply-To: <200605300302.k4U321t6026244@shell0.pdx.osdl.net> Content-Type: multipart/mixed; boundary="------------020206040109000403080807" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3614 Lines: 104 This is a multi-part message in MIME format. --------------020206040109000403080807 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit akpm@osdl.org wrote: > The patch titled > > i386: fix get_segment_eip() with vm86 segments > > has been added to the -mm tree. Its filename is > > i386-fix-get_segment_eip-with-vm86.patch > > See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find > out what to do about this > > ------------------------------------------------------ > Subject: i386: fix get_segment_eip() with vm86 segments > From: Chuck Ebbert <76306.1226@compuserve.com> > > > We need to check for vm86 mode first before looking at selector privilege > bits. > > Segment limit is always base + 64k and only the low 16 bits of EIP are > significant in vm86 mode. > > Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> > Cc: Andi Kleen > Cc: Zachary Amsden > Cc: Rohit Seth > Signed-off-by: Andrew Morton > --- > > arch/i386/mm/fault.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff -puN arch/i386/mm/fault.c~i386-fix-get_segment_eip-with-vm86 arch/i386/mm/fault.c > --- devel/arch/i386/mm/fault.c~i386-fix-get_segment_eip-with-vm86 2006-05-29 20:06:19.000000000 -0700 > +++ devel-akpm/arch/i386/mm/fault.c 2006-05-29 20:06:19.000000000 -0700 > @@ -77,12 +77,15 @@ static inline unsigned long get_segment_ > unsigned seg = regs->xcs & 0xffff; > u32 seg_ar, seg_limit, base, *desc; > > + /* Unlikely, but must come before segment checks. */ > + if (unlikely(regs->eflags & VM_MASK)) { > + base = seg << 4; > + *eip_limit = base + 0xffff; > + return base + (eip & 0xffff); > + } > + > /* The standard kernel/user address space limit. */ > *eip_limit = (seg & 3) ? USER_DS.seg : KERNEL_DS.seg; > - > - /* Unlikely, but must come before segment checks. */ > - if (unlikely((regs->eflags & VM_MASK) != 0)) > - return eip + (seg << 4); > > /* By far the most common cases. */ > if (likely(seg == __USER_CS || seg == __KERNEL_CS)) > _ > > Patches currently in -mm which might be from 76306.1226@compuserve.com are > > i386-let-usermode-execute-the-enter.patch > i386-fix-get_segment_eip-with-vm86.patch > > This looks great. While we're in the spirit let's fix kprobes v8086 handling as well by filtering out int3s from v8086 mode. --------------020206040109000403080807 Content-Type: text/plain; name="i386-dont-try-kprobes-for-v8086-mode" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="i386-dont-try-kprobes-for-v8086-mode" Never allow int3 traps from V8086 mode to enter the kprobes handler. Signed-off-by: Zachary Amsden Index: linux-2.6.17-rc/arch/i386/kernel/kprobes.c =================================================================== --- linux-2.6.17-rc.orig/arch/i386/kernel/kprobes.c 2006-05-18 13:31:50.000000000 -0700 +++ linux-2.6.17-rc/arch/i386/kernel/kprobes.c 2006-05-31 13:09:26.000000000 -0700 @@ -607,7 +607,7 @@ int __kprobes kprobe_exceptions_notify(s struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; - if (args->regs && user_mode(args->regs)) + if (args->regs && user_mode_vm(args->regs)) return ret; switch (val) { --------------020206040109000403080807-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/