Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752711AbbKJLV5 (ORCPT ); Tue, 10 Nov 2015 06:21:57 -0500 Received: from mail.skyhub.de ([78.46.96.112]:60494 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752535AbbKJLVz (ORCPT ); Tue, 10 Nov 2015 06:21:55 -0500 Date: Tue, 10 Nov 2015 12:21:42 +0100 From: Borislav Petkov To: Tony Luck Cc: linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH 2/3] x86, ras: Extend machine check recovery code to annotated ring0 areas Message-ID: <20151110112142.GD19187@pd.tnic> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2439 Lines: 77 On Fri, Nov 06, 2015 at 01:01:55PM -0800, Tony Luck wrote: > Extend the severity checking code to add a new context IN_KERN_RECOV > which is used to indicate that the machine check was triggered by code > in the kernel with a fixup entry. > > Add code to check for this situation and respond by altering the return > IP to the fixup address and changing the regs->ax so that the recovery > code knows the physical address of the error. Note that we also set bit > 63 because 0x0 is a legal physical address. > > Signed-off-by: Tony Luck > --- > arch/x86/kernel/cpu/mcheck/mce-severity.c | 19 +++++++++++++++++-- > arch/x86/kernel/cpu/mcheck/mce.c | 13 ++++++++++--- > 2 files changed, 27 insertions(+), 5 deletions(-) ... > diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c > index 9d014b82a124..472d11150b7a 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce.c > +++ b/arch/x86/kernel/cpu/mcheck/mce.c > @@ -31,6 +31,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -1132,9 +1133,15 @@ void do_machine_check(struct pt_regs *regs, long error_code) You could save a precious indentation level here: if (cfg->tolerant == 3) goto clear; and add the "clear" label below. clear: if (worst > 0) mce_report_event(regs); mce_wrmsrl(MSR_IA32_MCG_STATUS, 0) > if (no_way_out) > mce_panic("Fatal machine check on current CPU", &m, msg); > if (worst == MCE_AR_SEVERITY) { > - recover_paddr = m.addr; > - if (!(m.mcgstatus & MCG_STATUS_RIPV)) > - flags |= MF_MUST_KILL; > + if ((m.cs & 3) == 3) { > + recover_paddr = m.addr; > + if (!(m.mcgstatus & MCG_STATUS_RIPV)) > + flags |= MF_MUST_KILL; > + } else if (fixup_mcexception(regs)) { > + regs->ax = BIT(63) | m.addr; > + } else > + mce_panic("Failed kernel mode recovery", > + &m, NULL); > } else if (kill_it) { > force_sig(SIGBUS, current); > } > -- > 2.1.4 > > -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- 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/