From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Kees Cook <keescook@chromium.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Thomas Lendacky <Thomas.Lendacky@amd.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: [patch 01/15] x86/tlb: Uninline __get_current_cr3_fast()
Date: Sun, 19 Apr 2020 22:31:38 +0200 [thread overview]
Message-ID: <20200419203335.748016385@linutronix.de> (raw)
In-Reply-To: 20200419203137.214111265@linutronix.de
cpu_tlbstate is exported because various TLB related functions need access
to it, but cpu_tlbstate is sensitive information which should only be
accessed by well contained kernel functions and not be directly exposed to
modules.
In preparation of unexporting cpu_tlbstate move __get_current_cr3_fast()
into the x86 TLB management code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/mmu_context.h | 19 +------------------
arch/x86/mm/tlb.c | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+), 18 deletions(-)
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -225,24 +225,7 @@ static inline bool arch_vma_access_permi
return __pkru_allows_pkey(vma_pkey(vma), write);
}
-/*
- * This can be used from process context to figure out what the value of
- * CR3 is without needing to do a (slow) __read_cr3().
- *
- * It's intended to be used for code like KVM that sneakily changes CR3
- * and needs to restore it. It needs to be used very carefully.
- */
-static inline unsigned long __get_current_cr3_fast(void)
-{
- unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
- this_cpu_read(cpu_tlbstate.loaded_mm_asid));
-
- /* For now, be very restrictive about when this can be called. */
- VM_WARN_ON(in_nmi() || preemptible());
-
- VM_BUG_ON(cr3 != __read_cr3());
- return cr3;
-}
+unsigned long __get_current_cr3_fast(void);
typedef struct {
struct mm_struct *mm;
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -844,6 +844,26 @@ void flush_tlb_kernel_range(unsigned lon
}
/*
+ * This can be used from process context to figure out what the value of
+ * CR3 is without needing to do a (slow) __read_cr3().
+ *
+ * It's intended to be used for code like KVM that sneakily changes CR3
+ * and needs to restore it. It needs to be used very carefully.
+ */
+unsigned long __get_current_cr3_fast(void)
+{
+ unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
+ this_cpu_read(cpu_tlbstate.loaded_mm_asid));
+
+ /* For now, be very restrictive about when this can be called. */
+ VM_WARN_ON(in_nmi() || preemptible());
+
+ VM_BUG_ON(cr3 != __read_cr3());
+ return cr3;
+}
+EXPORT_SYMBOL_GPL(__get_current_cr3_fast);
+
+/*
* arch_tlbbatch_flush() performs a full TLB flush regardless of the active mm.
* This means that the 'struct flush_tlb_info' that describes which mappings to
* flush is actually fixed. We therefore set a single fixed struct and use it in
next prev parent reply other threads:[~2020-04-19 20:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 20:31 [patch 00/15] x86/tlb: Unexport per-CPU tlbstate Thomas Gleixner
2020-04-19 20:31 ` Thomas Gleixner [this message]
2020-04-19 20:31 ` [patch 02/15] x86/cpu: Uninline CR4 accessors Thomas Gleixner
2020-04-20 9:01 ` Christoph Hellwig
2020-04-20 9:34 ` Borislav Petkov
2020-04-20 17:25 ` Thomas Gleixner
2020-04-19 20:31 ` [patch 03/15] x86/cr4: Sanitize CR4.PCE update Thomas Gleixner
2020-04-19 20:31 ` [patch 04/15] x86/alternatives: Move temporary_mm helpers into C Thomas Gleixner
2020-04-19 20:31 ` [patch 05/15] x86/tlb: Move __flush_tlb() out of line Thomas Gleixner
2020-04-20 13:48 ` Tom Lendacky
2020-04-20 14:03 ` Jürgen Groß
2020-04-20 14:26 ` Tom Lendacky
2020-04-20 14:38 ` Jürgen Groß
2020-04-20 18:30 ` Tom Lendacky
2020-04-19 20:31 ` [patch 06/15] x86/tlb: Move __flush_tlb_global() " Thomas Gleixner
2020-04-19 20:31 ` [patch 07/15] x86/tlb: Move __flush_tlb_one_user() " Thomas Gleixner
2020-04-19 20:31 ` [patch 08/15] x86/tlb: Move __flush_tlb_one_kernel() " Thomas Gleixner
2020-04-19 20:31 ` [patch 09/15] x86/tlb: Move flush_tlb_others() " Thomas Gleixner
2020-04-19 20:31 ` [patch 10/15] x86/tlb: Move paravirt_tlb_remove_table() to the usage site Thomas Gleixner
2020-04-19 20:31 ` [patch 11/15] x86/tlb: Move cr4_set_bits_and_update_boot() " Thomas Gleixner
2020-04-19 20:31 ` [patch 12/15] x86/tlb: Uninline nmi_uaccess_okay() Thomas Gleixner
2020-04-19 20:31 ` [patch 13/15] x86/tlb: Move PCID helpers where they are used Thomas Gleixner
2020-04-19 20:31 ` [patch 14/15] xen/privcmd: Remove unneeded asm/tlb.h include Thomas Gleixner
2020-04-19 20:31 ` [patch 15/15] x86/tlb: Restrict access to tlbstate Thomas Gleixner
2020-04-20 9:20 ` [patch 00/15] x86/tlb: Unexport per-CPU tlbstate Christoph Hellwig
2020-04-20 16:58 ` Alexandre Chartre
2020-04-20 20:08 ` Thomas Gleixner
2020-04-20 17:27 ` Thomas Gleixner
2020-04-21 8:09 ` Sean Christopherson
2020-04-21 9:09 ` Thomas Gleixner
2020-04-22 0:42 ` Sean Christopherson
2020-04-20 10:25 ` Peter Zijlstra
2020-04-20 16:33 ` Alexandre Chartre
2020-04-21 17:10 ` Andy Lutomirski
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