linux-kernel - [PATCH] x86: Allow kernel_map_pages_in

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 08 Jul 2014 17:31:12 -0500
From:	Stuart Hayes <stuart.w.hayes@...il.com>
To:	tglx@...utronix.de, mingo@...hat.com, hpa@...or.com, x86@...nel.org
CC:	linux-kernel@...r.kernel.org, bpetkov@...e.com,
	matt.fleming@...el.com
Subject: [PATCH] x86: Allow kernel_map_pages_in_pgd() to work when NX is disabled

The function kernel_map_pages_in_pgd() will not map pages if NX is
disabled, which causes a lot of problems booting in EFI mode
(efi_map_region() and other functions depend on this).  This patch
just makes sure that the NX flag doesn't get set in the page tables
if NX is disabled, rather than not mapping the pages at all.

Signed-off-by: Stuart Hayes <stuart.w.hayes@...il.com>
---
--- linux-3.16-rc3/arch/x86/mm/pageattr.c.orig	2014-07-02 12:04:49.244288159 -0400
+++ linux-3.16-rc3/arch/x86/mm/pageattr.c	2014-07-02 12:05:55.808290437 -0400
@@ -1862,10 +1862,7 @@ int kernel_map_pages_in_pgd(pgd_t *pgd,
 		.flags = 0,
 	};
 
-	if (!(__supported_pte_mask & _PAGE_NX))
-		goto out;
-
-	if (!(page_flags & _PAGE_NX))
+	if ((!(__supported_pte_mask & _PAGE_NX)) || !(page_flags & _PAGE_NX))
 		cpa.mask_clr = __pgprot(_PAGE_NX);
 
 	cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/