linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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, luto@kernel.org,
	torvalds@linux-foundation.org, keescook@google.com,
	hughd@google.com, x86@kernel.org
Subject: [PATCH 10/23] x86, kaiser: make sure static PGDs are 8k in size
Date: Tue, 31 Oct 2017 15:32:05 -0700	[thread overview]
Message-ID: <20171031223205.951EFCB6@viggo.jf.intel.com> (raw)
In-Reply-To: <20171031223146.6B47C861@viggo.jf.intel.com>


We have a few PGDs that come out of the kernel binary instead of being
allocated dynamically.  Before this patch, they are all 8k-aligned,
but we also need them to be 8k in *size*e

The original KAISER patch did not do this.  It probably just lucked out
that it did not trample over data after the last PGD.

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: 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/kernel/head_64.S |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff -puN arch/x86/kernel/head_64.S~kaiser-head_S-pgds-need-8k-too arch/x86/kernel/head_64.S
--- a/arch/x86/kernel/head_64.S~kaiser-head_S-pgds-need-8k-too	2017-10-31 15:03:53.866279568 -0700
+++ b/arch/x86/kernel/head_64.S	2017-10-31 15:03:53.870279757 -0700
@@ -340,11 +340,24 @@ GLOBAL(early_recursion_flag)
 GLOBAL(name)
 
 #ifdef CONFIG_KAISER
+/*
+ * Each PGD needs to be 8k long and 8k aligned.  We do not
+ * ever go out to userspace with these, so we do not
+ * strictly *need* the second page, but this allows us to
+ * have a single set_pgd() implementation that does not
+ * need to worry about whether it has 4k or 8k to work
+ * with.
+ *
+ * This ensures PGDs are 8k long:
+ */
+#define KAISER_USER_PGD_FILL	512
+/* This ensures they are 8k-aligned: */
 #define NEXT_PGD_PAGE(name) \
 	.balign 2 * PAGE_SIZE; \
 GLOBAL(name)
 #else
 #define NEXT_PGD_PAGE(name) NEXT_PAGE(name)
+#define KAISER_USER_PGD_FILL	0
 #endif
 
 /* Automate the creation of 1 to 1 mapping pmd entries */
@@ -363,6 +376,7 @@ NEXT_PGD_PAGE(early_top_pgt)
 #else
 	.quad	level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
 #endif
+	.fill	KAISER_USER_PGD_FILL,8,0
 
 NEXT_PAGE(early_dynamic_pgts)
 	.fill	512*EARLY_DYNAMIC_PAGE_TABLES,8,0
@@ -372,6 +386,7 @@ NEXT_PAGE(early_dynamic_pgts)
 #ifndef CONFIG_XEN
 NEXT_PGD_PAGE(init_top_pgt)
 	.fill	512,8,0
+	.fill	KAISER_USER_PGD_FILL,8,0
 #else
 NEXT_PGD_PAGE(init_top_pgt)
 	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
@@ -380,6 +395,7 @@ NEXT_PGD_PAGE(init_top_pgt)
 	.org    init_top_pgt + PGD_START_KERNEL*8, 0
 	/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
 	.quad   level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
+	.fill	KAISER_USER_PGD_FILL,8,0
 
 NEXT_PAGE(level3_ident_pgt)
 	.quad	level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
_

  parent reply	other threads:[~2017-10-31 22:35 UTC|newest]

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-31 22:31 [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-10-31 22:31 ` [PATCH 01/23] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-01  0:43   ` Brian Gerst
2017-11-01  1:08     ` Dave Hansen
2017-11-01 18:18   ` Borislav Petkov
2017-11-01 18:27     ` Dave Hansen
2017-11-01 20:42       ` Borislav Petkov
2017-11-01 21:01   ` Thomas Gleixner
2017-11-01 22:58     ` Dave Hansen
2017-10-31 22:31 ` [PATCH 02/23] x86, kaiser: do not set _PAGE_USER for init_mm page tables Dave Hansen
2017-11-01 21:11   ` Thomas Gleixner
2017-11-01 21:24     ` Andy Lutomirski
2017-11-01 21:28       ` Thomas Gleixner
2017-11-01 21:52         ` Dave Hansen
2017-11-01 22:11           ` Thomas Gleixner
2017-11-01 22:12           ` Linus Torvalds
2017-11-01 22:20             ` Thomas Gleixner
2017-11-01 22:45               ` Kees Cook
2017-11-02  7:10               ` Andy Lutomirski
2017-11-02 11:33                 ` Thomas Gleixner
2017-11-02 11:59                   ` Andy Lutomirski
2017-11-02 12:56                     ` Thomas Gleixner
2017-11-02 16:38                   ` Dave Hansen
2017-11-02 18:19                     ` Andy Lutomirski
2017-11-02 18:24                       ` Thomas Gleixner
2017-11-02 18:24                       ` Linus Torvalds
2017-11-02 18:40                         ` Thomas Gleixner
2017-11-02 18:57                           ` Linus Torvalds
2017-11-02 21:41                             ` Thomas Gleixner
2017-11-02  7:07         ` Andy Lutomirski
2017-11-02 11:21           ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 03/23] x86, kaiser: disable global pages Dave Hansen
2017-11-01 21:18   ` Thomas Gleixner
2017-11-01 22:12     ` Dave Hansen
2017-11-01 22:28       ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 04/23] x86, tlb: make CR4-based TLB flushes more robust Dave Hansen
2017-11-01  8:01   ` Andy Lutomirski
2017-11-01 10:11     ` Kirill A. Shutemov
2017-11-01 10:38       ` Andy Lutomirski
2017-11-01 10:56         ` Kirill A. Shutemov
2017-11-01 11:18           ` Andy Lutomirski
2017-11-01 22:21             ` Dave Hansen
2017-11-01 21:25   ` Thomas Gleixner
2017-11-01 22:24     ` Dave Hansen
2017-11-01 22:30       ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 05/23] x86, mm: document X86_CR4_PGE toggling behavior Dave Hansen
2017-10-31 23:31   ` Kees Cook
2017-10-31 22:31 ` [PATCH 06/23] x86, kaiser: introduce user-mapped percpu areas Dave Hansen
2017-11-01 21:47   ` Thomas Gleixner
2017-10-31 22:31 ` [PATCH 07/23] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-10-31 22:32 ` [PATCH 08/23] x86, kaiser: only populate shadow page tables for userspace Dave Hansen
2017-10-31 23:35   ` Kees Cook
2017-10-31 22:32 ` [PATCH 09/23] x86, kaiser: allow NX to be set in p4d/pgd Dave Hansen
2017-10-31 22:32 ` Dave Hansen [this message]
2017-10-31 22:32 ` [PATCH 11/23] x86, kaiser: map GDT into user page tables Dave Hansen
2017-10-31 22:32 ` [PATCH 12/23] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-01  8:00   ` Andy Lutomirski
2017-11-01  8:06     ` Ingo Molnar
2017-10-31 22:32 ` [PATCH 13/23] x86, kaiser: map espfix structures Dave Hansen
2017-10-31 22:32 ` [PATCH 14/23] x86, kaiser: map entry stack variables Dave Hansen
2017-10-31 22:32 ` [PATCH 15/23] x86, kaiser: map trace interrupt entry Dave Hansen
2017-10-31 22:32 ` [PATCH 16/23] x86, kaiser: map debug IDT tables Dave Hansen
2017-10-31 22:32 ` [PATCH 17/23] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-10-31 22:32 ` [PATCH 18/23] x86, mm: Move CR3 construction functions Dave Hansen
2017-10-31 22:32 ` [PATCH 19/23] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-10-31 22:32 ` [PATCH 20/23] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-10-31 22:32 ` [PATCH 21/23] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-01  8:03   ` Andy Lutomirski
2017-11-01 14:17     ` Dave Hansen
2017-11-01 20:31       ` Andy Lutomirski
2017-11-01 20:59         ` Dave Hansen
2017-11-01 21:04           ` Andy Lutomirski
2017-11-01 21:06             ` Dave Hansen
2017-10-31 22:32 ` [PATCH 22/23] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-10-31 22:32 ` [PATCH 23/23] x86, kaiser: add Kconfig Dave Hansen
2017-10-31 23:59   ` Kees Cook
2017-11-01  9:07     ` Borislav Petkov
2017-10-31 23:27 ` [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables Linus Torvalds
2017-10-31 23:44   ` Dave Hansen
2017-11-01  0:21     ` Dave Hansen
2017-11-01  7:59     ` Andy Lutomirski
2017-11-01 16:08     ` Linus Torvalds
2017-11-01 17:31       ` Dave Hansen
2017-11-01 17:58         ` Randy Dunlap
2017-11-01 18:27         ` Linus Torvalds
2017-11-01 18:46           ` Dave Hansen
2017-11-01 19:05             ` Linus Torvalds
2017-11-01 20:33               ` Andy Lutomirski
2017-11-02  7:32                 ` Andy Lutomirski
2017-11-02  7:54                   ` Andy Lutomirski
2017-11-01 15:53   ` Dave Hansen
2017-11-01  8:54 ` Ingo Molnar
2017-11-01 14:09   ` Thomas Gleixner
2017-11-01 22:14   ` Dave Hansen
2017-11-01 22:28     ` Linus Torvalds
2017-11-02  8:03     ` Peter Zijlstra
2017-11-03 11:07     ` Kirill A. Shutemov
2017-11-02 19:01 ` Will Deacon
2017-11-02 19:38   ` Dave Hansen
2017-11-03 13:41     ` Will Deacon
2017-11-22 16:19 ` Pavel Machek
2017-11-23 10:47   ` Pavel Machek

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=20171031223205.951EFCB6@viggo.jf.intel.com \
    --to=dave.hansen@linux.intel.com \
    --cc=daniel.gruss@iaik.tugraz.at \
    --cc=hughd@google.com \
    --cc=keescook@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=michael.schwarz@iaik.tugraz.at \
    --cc=moritz.lipp@iaik.tugraz.at \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).