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 11/30] x86, kaiser: make sure static PGDs are 8k in size
Date: Wed, 08 Nov 2017 11:47:06 -0800 [thread overview]
Message-ID: <20171108194706.0669993F@viggo.jf.intel.com> (raw)
In-Reply-To: <20171108194646.907A1942@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.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: 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/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 2017-11-08 10:45:31.840681389 -0800
+++ b/arch/x86/kernel/head_64.S 2017-11-08 10:45:31.843681389 -0800
@@ -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
_
next prev parent reply other threads:[~2017-11-08 19:47 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 19:46 [PATCH 00/30] [v2] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-08 19:46 ` [PATCH 01/30] x86, mm: do not set _PAGE_USER for init_mm " Dave Hansen
2017-11-08 19:52 ` Linus Torvalds
2017-11-08 20:11 ` Dave Hansen
2017-11-09 10:29 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 02/30] x86, tlb: make CR4-based TLB flushes more robust Dave Hansen
2017-11-09 10:48 ` Borislav Petkov
2017-11-09 10:51 ` Thomas Gleixner
2017-11-09 11:02 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 03/30] x86, mm: document X86_CR4_PGE toggling behavior Dave Hansen
2017-11-09 12:21 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 04/30] x86, kaiser: disable global pages by default with KAISER Dave Hansen
2017-11-09 12:51 ` Borislav Petkov
2017-11-09 22:19 ` Thomas Gleixner
2017-11-08 19:46 ` [PATCH 05/30] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-09 13:20 ` Borislav Petkov
2017-11-09 15:34 ` Dave Hansen
2017-11-09 15:59 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 06/30] x86, kaiser: introduce user-mapped percpu areas Dave Hansen
2017-11-08 19:46 ` [PATCH 07/30] x86, kaiser: mark percpu data structures required for entry/exit Dave Hansen
2017-11-08 19:47 ` [PATCH 08/30] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-11-10 12:57 ` Ingo Molnar
2017-11-08 19:47 ` [PATCH 09/30] x86, kaiser: only populate shadow page tables for userspace Dave Hansen
2017-11-08 19:47 ` [PATCH 10/30] x86, kaiser: allow NX to be set in p4d/pgd Dave Hansen
2017-11-08 19:47 ` Dave Hansen [this message]
2017-11-08 19:47 ` [PATCH 12/30] x86, kaiser: map GDT into user page tables Dave Hansen
2017-11-08 19:47 ` [PATCH 13/30] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-08 19:47 ` [PATCH 14/30] x86, kaiser: map espfix structures Dave Hansen
2017-11-08 19:47 ` [PATCH 15/30] x86, kaiser: map entry stack variables Dave Hansen
2017-11-08 19:47 ` [PATCH 16/30] x86, kaiser: map trace interrupt entry Dave Hansen
2017-11-08 19:47 ` [PATCH 17/30] x86, kaiser: map debug IDT tables Dave Hansen
2017-11-08 19:47 ` [PATCH 18/30] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-10 12:17 ` Peter Zijlstra
2017-11-08 19:47 ` [PATCH 19/30] x86, mm: Move CR3 construction functions Dave Hansen
2017-11-08 19:47 ` [PATCH 20/30] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-11-10 12:20 ` Peter Zijlstra
2017-11-10 18:41 ` Dave Hansen
2017-11-08 19:47 ` [PATCH 21/30] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-11-08 19:47 ` [PATCH 22/30] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-10 12:25 ` Peter Zijlstra
2017-11-08 19:47 ` [PATCH 23/30] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-11-08 19:47 ` [PATCH 24/30] x86, kaiser: disable native VSYSCALL Dave Hansen
2017-11-09 19:04 ` Andy Lutomirski
2017-11-09 19:26 ` Dave Hansen
2017-11-10 0:53 ` Andy Lutomirski
2017-11-10 0:57 ` Dave Hansen
2017-11-10 1:04 ` Andy Lutomirski
2017-11-10 1:22 ` Dave Hansen
2017-11-10 2:25 ` Andy Lutomirski
2017-11-10 6:31 ` Dave Hansen
2017-11-10 22:06 ` Andy Lutomirski
2017-11-10 23:04 ` Dave Hansen
2017-11-13 3:52 ` Andy Lutomirski
2017-11-13 21:07 ` Dave Hansen
2017-11-14 2:15 ` Andy Lutomirski
2017-11-08 19:47 ` [PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime Dave Hansen
2017-11-08 19:47 ` [PATCH 26/30] x86, kaiser: add a function to check for KAISER being enabled Dave Hansen
2017-11-08 19:47 ` [PATCH 27/30] x86, kaiser: un-poison PGDs at runtime Dave Hansen
2017-11-08 19:47 ` [PATCH 28/30] x86, kaiser: allow KAISER to be enabled/disabled " Dave Hansen
2017-11-08 19:47 ` [PATCH 29/30] x86, kaiser: add Kconfig Dave Hansen
2017-11-08 19:47 ` [PATCH 30/30] x86, kaiser, xen: Dynamically disable KAISER when running under Xen PV Dave Hansen
2017-11-09 15:01 ` Juergen Gross
2017-11-10 19:30 [PATCH 00/30] [v3] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-10 19:31 ` [PATCH 11/30] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
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