From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 1627D828F3 for ; Fri, 12 Feb 2016 16:02:51 -0500 (EST) Received: by mail-pa0-f50.google.com with SMTP id fl4so40304942pad.0 for ; Fri, 12 Feb 2016 13:02:51 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id sm4si22146491pac.245.2016.02.12.13.02.36 for ; Fri, 12 Feb 2016 13:02:36 -0800 (PST) Subject: [PATCH 10/33] x86, pkeys: new page fault error code bit: PF_PK From: Dave Hansen Date: Fri, 12 Feb 2016 13:02:07 -0800 References: <20160212210152.9CAD15B0@viggo.jf.intel.com> In-Reply-To: <20160212210152.9CAD15B0@viggo.jf.intel.com> Message-Id: <20160212210207.DA7B43E6@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, torvalds@linux-foundation.org, Dave Hansen , dave.hansen@linux.intel.com From: Dave Hansen Note: "PK" is how the Intel SDM refers to this bit, so we also use that nomenclature. This only defines the bit, it does not plumb it anywhere to be handled. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner --- b/arch/x86/mm/fault.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN arch/x86/mm/fault.c~pkeys-05-pfec arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-05-pfec 2016-02-12 10:44:18.080331119 -0800 +++ b/arch/x86/mm/fault.c 2016-02-12 10:44:18.084331302 -0800 @@ -33,6 +33,7 @@ * bit 2 == 0: kernel-mode access 1: user-mode access * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch + * bit 5 == 1: protection keys block access */ enum x86_pf_error_code { @@ -41,6 +42,7 @@ enum x86_pf_error_code { PF_USER = 1 << 2, PF_RSVD = 1 << 3, PF_INSTR = 1 << 4, + PF_PK = 1 << 5, }; /* @@ -916,6 +918,12 @@ static int spurious_fault_check(unsigned if ((error_code & PF_INSTR) && !pte_exec(*pte)) return 0; + /* + * Note: We do not do lazy flushing on protection key + * changes, so no spurious fault will ever set PF_PK. + */ + if ((error_code & PF_PK)) + return 1; return 1; } _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org