From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, dave.hansen@linux.intel.com,
moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at,
michael.schwarz@iaik.tugraz.at,
richard.fellner@student.tugraz.at, luto@kernel.org,
torvalds@linux-foundation.org, keescook@google.com,
hughd@google.com, x86@kernel.org
Subject: [PATCH 06/23] x86, kaiser: allow NX poison to be set in p4d/pgd
Date: Wed, 22 Nov 2017 16:34:48 -0800 [thread overview]
Message-ID: <20171123003448.C6AB3575@viggo.jf.intel.com> (raw)
In-Reply-To: <20171123003438.48A0EEDE@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
The user portion of the kernel page tables use the NX bit to
poison them for userspace. But, that trips the p4d/pgd_bad()
checks. Make sure it does not do that.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: x86@kernel.org
---
b/arch/x86/include/asm/pgtable.h | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff -puN arch/x86/include/asm/pgtable.h~kaiser-p4d-allow-nx arch/x86/include/asm/pgtable.h
--- a/arch/x86/include/asm/pgtable.h~kaiser-p4d-allow-nx 2017-11-22 15:45:47.382619743 -0800
+++ b/arch/x86/include/asm/pgtable.h 2017-11-22 15:45:47.386619743 -0800
@@ -846,7 +846,12 @@ static inline pud_t *pud_offset(p4d_t *p
static inline int p4d_bad(p4d_t p4d)
{
- return (p4d_flags(p4d) & ~(_KERNPG_TABLE | _PAGE_USER)) != 0;
+ unsigned long ignore_flags = _KERNPG_TABLE | _PAGE_USER;
+
+ if (IS_ENABLED(CONFIG_KAISER))
+ ignore_flags |= _PAGE_NX;
+
+ return (p4d_flags(p4d) & ~ignore_flags) != 0;
}
#endif /* CONFIG_PGTABLE_LEVELS > 3 */
@@ -880,7 +885,12 @@ static inline p4d_t *p4d_offset(pgd_t *p
static inline int pgd_bad(pgd_t pgd)
{
- return (pgd_flags(pgd) & ~_PAGE_USER) != _KERNPG_TABLE;
+ unsigned long ignore_flags = _PAGE_USER;
+
+ if (IS_ENABLED(CONFIG_KAISER))
+ ignore_flags |= _PAGE_NX;
+
+ return (pgd_flags(pgd) & ~ignore_flags) != _KERNPG_TABLE;
}
static inline int pgd_none(pgd_t pgd)
_
--
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next prev parent reply other threads:[~2017-11-23 0:35 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-23 0:34 [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-23 0:34 ` [PATCH 01/23] x86, kaiser: disable global pages by default with KAISER Dave Hansen
2017-11-23 0:34 ` [PATCH 02/23] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-23 0:34 ` [PATCH 03/23] x86, kaiser: introduce user-mapped per-cpu areas Dave Hansen
2017-11-23 0:34 ` [PATCH 04/23] x86, kaiser: mark per-cpu data structures required for entry/exit Dave Hansen
2017-11-23 0:34 ` [PATCH 05/23] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-11-23 4:07 ` Andy Lutomirski
2017-11-26 16:10 ` Andy Lutomirski
2017-11-26 16:24 ` Dave Hansen
2017-11-26 16:29 ` Andy Lutomirski
2018-01-05 4:16 ` Yisheng Xie
2018-01-05 5:18 ` Dave Hansen
2018-01-05 6:16 ` Yisheng Xie
2018-01-05 6:29 ` Dave Hansen
2018-01-05 11:49 ` Andrea Arcangeli
2018-01-05 18:19 ` Jiri Kosina
2018-01-05 19:00 ` Jiri Kosina
2018-01-05 19:03 ` Dave Hansen
2018-01-05 19:17 ` Jiri Kosina
2018-01-05 19:18 ` Jiri Kosina
2018-01-05 19:55 ` Andrea Arcangeli
2018-01-05 21:07 ` Dave Hansen
2018-01-05 21:14 ` Jiri Kosina
2018-01-05 21:29 ` Andy Lutomirski
2018-01-05 22:48 ` Hugh Dickins
2018-01-06 4:54 ` Hanjun Guo
2018-01-06 6:06 ` Dave Hansen
2018-01-06 6:28 ` Hanjun Guo
2018-01-06 6:53 ` Hanjun Guo
2018-01-06 7:55 ` Dave Hansen
2018-01-06 8:42 ` Hanjun Guo
2018-01-06 7:51 ` Dave Hansen
2018-01-06 17:22 ` Andrea Arcangeli
2017-11-23 0:34 ` Dave Hansen [this message]
2017-11-23 0:34 ` [PATCH 07/23] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
2017-11-23 0:34 ` [PATCH 08/23] x86, kaiser: map cpu entry area Dave Hansen
2017-11-23 0:34 ` [PATCH 09/23] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-23 19:42 ` Eric Biggers
2017-11-23 20:12 ` Andy Lutomirski
2017-11-23 0:34 ` [PATCH 10/23] x86, kaiser: map espfix structures Dave Hansen
2017-11-23 0:34 ` [PATCH 11/23] x86, kaiser: map entry stack variables Dave Hansen
2017-11-23 3:31 ` Andy Lutomirski
2017-11-23 15:37 ` Dave Hansen
2017-11-23 15:55 ` Andy Lutomirski
2017-11-23 0:35 ` [PATCH 12/23] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-23 0:35 ` [PATCH 13/23] x86, mm: Move CR3 construction functions Dave Hansen
2017-11-23 0:35 ` [PATCH 14/23] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-11-23 0:35 ` [PATCH 15/23] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-11-23 0:35 ` [PATCH 16/23] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-23 0:35 ` [PATCH 17/23] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-11-23 0:35 ` [PATCH 18/23] x86, kaiser: disable native VSYSCALL Dave Hansen
2017-11-23 0:35 ` [PATCH 19/23] x86, kaiser: add debugfs file to turn KAISER on/off at runtime Dave Hansen
2017-11-23 0:35 ` [PATCH 20/23] x86, kaiser: add a function to check for KAISER being enabled Dave Hansen
2017-11-25 1:23 ` Eduardo Valentin
2017-11-23 0:35 ` [PATCH 21/23] x86, kaiser: un-poison PGDs at runtime Dave Hansen
2017-11-25 1:17 ` Eduardo Valentin
2017-11-23 0:35 ` [PATCH 22/23] x86, kaiser: allow KAISER to be enabled/disabled " Dave Hansen
2017-11-23 0:35 ` [PATCH 23/23] x86, kaiser: add Kconfig Dave Hansen
2017-11-23 7:23 ` [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Ingo Molnar
2017-11-23 7:27 ` Ingo Molnar
2017-11-23 7:32 ` Ingo Molnar
2017-11-23 15:02 ` Dave Hansen
2017-11-23 16:20 ` Dave Hansen
2017-11-24 6:35 ` Ingo Molnar
2017-11-24 6:41 ` Dave Hansen
2017-11-24 7:33 ` Ingo Molnar
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