From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, dave.hansen@linux.intel.com,
tglx@linutronix.de, 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 01/30] x86, mm: do not set _PAGE_USER for init_mm page tables
Date: Wed, 08 Nov 2017 11:46:47 -0800 [thread overview]
Message-ID: <20171108194647.ABC9BC79@viggo.jf.intel.com> (raw)
In-Reply-To: <20171108194646.907A1942@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
init_mm is for kernel-exclusive use. If someone is allocating page
tables for it, do not set _PAGE_USER on them.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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/pgalloc.h | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)
diff -puN arch/x86/include/asm/pgalloc.h~kaiser-prep-clear-_PAGE_USER-for-init_mm arch/x86/include/asm/pgalloc.h
--- a/arch/x86/include/asm/pgalloc.h~kaiser-prep-clear-_PAGE_USER-for-init_mm 2017-11-08 10:45:25.928681403 -0800
+++ b/arch/x86/include/asm/pgalloc.h 2017-11-08 10:45:25.931681403 -0800
@@ -61,20 +61,37 @@ static inline void __pte_free_tlb(struct
___pte_free_tlb(tlb, pte);
}
+/*
+ * init_mm is for kernel-exclusive use. Any page tables that
+ * are seteup for it should not be usable by userspace.
+ *
+ * This also *signals* to code (like KAISER) that this page table
+ * entry is for kernel-exclusive use.
+ */
+static inline pteval_t mm_pgtable_flags(struct mm_struct *mm)
+{
+ if (!mm || (mm == &init_mm))
+ return _KERNPG_TABLE;
+ return _PAGE_TABLE;
+}
+
static inline void pmd_populate_kernel(struct mm_struct *mm,
pmd_t *pmd, pte_t *pte)
{
+ pteval_t pgtable_flags = mm_pgtable_flags(mm);
+
paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
- set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
+ set_pmd(pmd, __pmd(__pa(pte) | pgtable_flags));
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
struct page *pte)
{
+ pteval_t pgtable_flags = mm_pgtable_flags(mm);
unsigned long pfn = page_to_pfn(pte);
paravirt_alloc_pte(mm, pfn);
- set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
+ set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | pgtable_flags));
}
#define pmd_pgtable(pmd) pmd_page(pmd)
@@ -117,16 +134,20 @@ extern void pud_populate(struct mm_struc
#else /* !CONFIG_X86_PAE */
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
+ pteval_t pgtable_flags = mm_pgtable_flags(mm);
+
paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
- set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
+ set_pud(pud, __pud(__pa(pmd) | pgtable_flags));
}
#endif /* CONFIG_X86_PAE */
#if CONFIG_PGTABLE_LEVELS > 3
static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
{
+ pteval_t pgtable_flags = mm_pgtable_flags(mm);
+
paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
- set_p4d(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
+ set_p4d(p4d, __p4d(__pa(pud) | pgtable_flags));
}
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
@@ -155,8 +176,10 @@ static inline void __pud_free_tlb(struct
#if CONFIG_PGTABLE_LEVELS > 4
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
{
+ pteval_t pgtable_flags = mm_pgtable_flags(mm);
+
paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
- set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
+ set_pgd(pgd, __pgd(__pa(p4d) | pgtable_flags));
}
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
_
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 ` Dave Hansen [this message]
2017-11-08 19:52 ` [PATCH 01/30] x86, mm: do not set _PAGE_USER for init_mm " 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 ` [PATCH 11/30] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
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 01/30] x86, mm: do not set _PAGE_USER for init_mm " Dave Hansen
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