From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx495+wcXOQ67CsMvQuDDIcL6Gl8N/psiZ19ntB6zO6DMTtnvcw3lXVFBRblVcCFOZjwkZrab ARC-Seal: i=1; a=rsa-sha256; t=1523517308; cv=none; d=google.com; s=arc-20160816; b=GjL3yc/gM0fStpcK0DzJEH68qQ4GVyud2/wcqGRhrAiteLigN05y3ycj7q55ukRshj H/I3zNDKvQ/XOp+rEIFtKattU/lJ5nNbDHZ3hyEjV5ur4SEeWFmE6HwSwvBH4iEQk8kc nxiEXWk1UzMQ8TRFI7zSeyGxa2OXrHOW3kpjr1ck+70EmOibGUfNZ+7+OUmSsJrYZt6X KUA1WemB3I3H8DgIJ4VCpomJ4bBPmIIXWDPRZVGid3nfMOchRvcOG6DJRHTY+9TyV+IX kvvYSUgqG7O5aHV65yLrDYitfcd29D2Uy0XGYgBNk5DdRqMj1HGbZgL1WjVpK7eRbO1N Z+vQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=precedence:content-disposition:content-transfer-encoding :mime-version:robot-unsubscribe:robot-id:git-commit-id:subject:to :references:in-reply-to:reply-to:cc:message-id:from:sender:date :arc-authentication-results; bh=rVjUifQl0FFbr6o9TJXyylU54fYojEEmMOjQSZ6s8Dc=; b=M1uFKBUiiaqaTgb/Y4J43HV9kTaPRdF8uluEslQrlQqVwLtuLvRBnbo+zEyb383eKJ nm6M5qyLX//+aSplgOxCTGjeTu9T+CDyCpY1IqOfQacss4L6KlkWq2bzTbsBiYJIO1Ij M7vWk+7hcJbV0wjpdmNXmnj1SlnObjwVrYDtGMwCQdwwzRzBi/fXEzOt6WaK4WXMQE7o uBbIcmGwWRoC7RZQEZQBIYG1rSkE7WxZfT22tM6yxTSK32MfgSDeqSydTnvsjdO0Z11z hNjLV6WcL8+n+nZ5aAOCLs0Jaffua4kmdcFDUpghUOiSWy+QByz5dQBMyes0K1CQQE4C PMdw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of tipbot@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=tipbot@zytor.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of tipbot@zytor.com designates 198.137.202.136 as permitted sender) smtp.mailfrom=tipbot@zytor.com Date: Thu, 12 Apr 2018 00:14:20 -0700 Sender: tip tree robot From: tip-bot for Dave Hansen Message-ID: Cc: dan.j.williams@intel.com, jpoimboe@redhat.com, tglx@linutronix.de, dwmw2@infradead.org, luto@kernel.org, namit@vmware.com, torvalds@linux-foundation.org, peterz@infradead.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, hughd@google.com, keescook@google.com, jgross@suse.com, bp@alien8.de, mingo@kernel.org, hpa@zytor.com, arjan@linux.intel.com, aarcange@redhat.com, dave.hansen@linux.intel.com Reply-To: keescook@google.com, hughd@google.com, mingo@kernel.org, bp@alien8.de, jgross@suse.com, arjan@linux.intel.com, hpa@zytor.com, aarcange@redhat.com, dave.hansen@linux.intel.com, tglx@linutronix.de, dan.j.williams@intel.com, jpoimboe@redhat.com, luto@kernel.org, dwmw2@infradead.org, torvalds@linux-foundation.org, namit@vmware.com, gregkh@linuxfoundation.org, peterz@infradead.org, linux-kernel@vger.kernel.org In-Reply-To: <20180406205511.BC072352@viggo.jf.intel.com> References: <20180406205511.BC072352@viggo.jf.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/pti] x86/mm: Remove extra filtering in pageattr code Git-Commit-ID: 1a54420aeb4da1ba5b28283aa5696898220c9a27 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597289629374494511?= X-GMAIL-MSGID: =?utf-8?q?1597523685694004764?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Commit-ID: 1a54420aeb4da1ba5b28283aa5696898220c9a27 Gitweb: https://git.kernel.org/tip/1a54420aeb4da1ba5b28283aa5696898220c9a27 Author: Dave Hansen AuthorDate: Fri, 6 Apr 2018 13:55:11 -0700 Committer: Ingo Molnar CommitDate: Thu, 12 Apr 2018 09:05:58 +0200 x86/mm: Remove extra filtering in pageattr code The pageattr code has a mode where it can set or clear PTE bits in existing PTEs, so the page protections of the *new* PTEs come from one of two places: 1. The set/clear masks: cpa->mask_clr / cpa->mask_set 2. The existing PTE We filter ->mask_set/clr for supported PTE bits at entry to __change_page_attr() so we never need to filter them again. The only other place permissions can come from is an existing PTE and those already presumably have good bits. We do not need to filter them again. Signed-off-by: Dave Hansen Cc: Andrea Arcangeli Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Linus Torvalds Cc: Nadav Amit Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205511.BC072352@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index d3442dfdfced..968f51a2e39b 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -598,7 +598,6 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, req_prot = pgprot_clear_protnone_bits(req_prot); if (pgprot_val(req_prot) & _PAGE_PRESENT) pgprot_val(req_prot) |= _PAGE_PSE; - req_prot = canon_pgprot(req_prot); /* * old_pfn points to the large page base pfn. So we need @@ -718,7 +717,7 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, */ pfn = ref_pfn; for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc) - set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot))); + set_pte(&pbase[i], pfn_pte(pfn, ref_prot)); if (virt_addr_valid(address)) { unsigned long pfn = PFN_DOWN(__pa(address)); @@ -935,7 +934,6 @@ static void populate_pte(struct cpa_data *cpa, pte = pte_offset_kernel(pmd, start); pgprot = pgprot_clear_protnone_bits(pgprot); - pgprot = canon_pgprot(pgprot); while (num_pages-- && start < end) { set_pte(pte, pfn_pte(cpa->pfn, pgprot)); @@ -1234,7 +1232,7 @@ repeat: * after all we're only going to change it's attributes * not the memory it points to */ - new_pte = pfn_pte(pfn, canon_pgprot(new_prot)); + new_pte = pfn_pte(pfn, new_prot); cpa->pfn = pfn; /* * Do we really change anything ?