LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Andi Kleen <ak@suse.de>
To: mingo@elte.hu, tglx@linutronix.de, linux-kernel@vger.kernel.org
Subject: [PATCH] [3/5] CPA: Make advised protection check truly advisory
Date: Fri,  8 Feb 2008 14:27:46 +0100 (CET)	[thread overview]
Message-ID: <20080208132746.34FB51B41BB@basil.firstfloor.org> (raw)
In-Reply-To: <20080208227.168531243@suse.de>


Only force RO in the advisory protection checks when all pages in the 
range are RO. Previously it would trigger when any page in the range
was ro.

I believe this will make try_preserve_large_page much safer to use.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 arch/x86/mm/pageattr.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Index: linux/arch/x86/mm/pageattr.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr.c
+++ linux/arch/x86/mm/pageattr.c
@@ -191,14 +191,14 @@ advised_static_prot(pgprot_t prot, unsig
 {
 #ifdef CONFIG_DEBUG_RODATA
 	/* The .rodata section needs to be read-only */
-	if (within_range(start, end, (unsigned long)__start_rodata,
-				(unsigned long)__end_rodata))
+	if (within_range((unsigned long)__start_rodata,
+				(unsigned long)__end_rodata, start, end))
 		pgprot_val(prot) &= ~_PAGE_RW;
 	/*
 	 * Do the same for the x86-64 high kernel mapping
 	 */
-	if (within_range(start, end, virt_to_highmap(__start_rodata),
-				virt_to_highmap(__end_rodata)))
+	if (within_range(virt_to_highmap(__start_rodata),
+				virt_to_highmap(__end_rodata), start, end))
 		pgprot_val(prot) &= ~_PAGE_RW;
 #endif
 	return prot;

  parent reply	other threads:[~2008-02-08 13:28 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-08 13:27 [PATCH] [1/5] CPA: Split static_protections into required_static_prot and advised_static_prot Andi Kleen
2008-02-08 13:27 ` [PATCH] [2/5] Support range checking for required/advisory protections Andi Kleen
2008-02-08 13:27 ` Andi Kleen [this message]
2008-02-08 13:27 ` [PATCH] [4/5] Don't use inline for the protection checks Andi Kleen
2008-02-08 13:27 ` [PATCH] [5/5] Switch i386 early boot page table initilization over to use required_static_prot() Andi Kleen
2008-02-08 16:36 [PATCH] [0/5] pageattr protection patchkit v2 for the latest kernel Andi Kleen
2008-02-08 16:36 ` [PATCH] [3/5] CPA: Make advised protection check truly advisory Andi Kleen
2008-02-09 15:38   ` Thomas Gleixner
2008-02-09 16:56     ` Andi Kleen
2008-02-09 17:38       ` Thomas Gleixner
2008-02-10  9:19         ` Andi Kleen
2008-02-10 16:50           ` Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20080208132746.34FB51B41BB@basil.firstfloor.org \
    --to=ak@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=tglx@linutronix.de \
    --subject='Re: [PATCH] [3/5] CPA: Make advised protection check truly advisory' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).