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Message-Id: <20200419203337.118146892@linutronix.de>
Date: Sun, 19 Apr 2020 22:31:52 +0200
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: x86@...nel.org, Kees Cook <keescook@...omium.org>,
Paolo Bonzini <pbonzini@...hat.com>,
Thomas Lendacky <Thomas.Lendacky@....com>,
Juergen Gross <jgross@...e.com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [patch 15/15] x86/tlb: Restrict access to tlbstate
Hide tlbstate, flush_tlb_info and related helpers when tlbflush.h is
included from a module. Modules have absolutely no business with these
internals.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/include/asm/tlbflush.h | 136 ++++++++++++++++++++--------------------
arch/x86/mm/init.c | 1
2 files changed, 69 insertions(+), 68 deletions(-)
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -13,20 +13,69 @@
#include <asm/pti.h>
#include <asm/processor-flags.h>
-struct flush_tlb_info;
-
void flush_tlb_local(void);
void flush_tlb_global(void);
-void flush_tlb_one_user(unsigned long addr);
-void flush_tlb_one_kernel(unsigned long addr);
-void flush_tlb_others(const struct cpumask *cpumask,
- const struct flush_tlb_info *info);
-#ifdef CONFIG_PARAVIRT
-#include <asm/paravirt.h>
-#endif
+#define TLB_FLUSH_ALL -1UL
/*
+ * flush everything
+ */
+static inline void __flush_tlb_all(void)
+{
+ /*
+ * This is to catch users with enabled preemption and the PGE feature
+ * and don't trigger the warning in __native_flush_tlb().
+ */
+ VM_WARN_ON_ONCE(preemptible());
+
+ if (boot_cpu_has(X86_FEATURE_PGE)) {
+ flush_tlb_global();
+ } else {
+ /*
+ * !PGE -> !PCID (setup_pcid()), thus every flush is total.
+ */
+ flush_tlb_local();
+ }
+}
+
+void cr4_update_irqsoff(unsigned long set, unsigned long clear);
+unsigned long cr4_read_shadow(void);
+
+/* Set in this cpu's CR4. */
+static inline void cr4_set_bits_irqsoff(unsigned long mask)
+{
+ cr4_update_irqsoff(mask, 0);
+}
+
+/* Clear in this cpu's CR4. */
+static inline void cr4_clear_bits_irqsoff(unsigned long mask)
+{
+ cr4_update_irqsoff(0, mask);
+}
+
+/* Set in this cpu's CR4. */
+static inline void cr4_set_bits(unsigned long mask)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cr4_set_bits_irqsoff(mask);
+ local_irq_restore(flags);
+}
+
+/* Clear in this cpu's CR4. */
+static inline void cr4_clear_bits(unsigned long mask)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cr4_clear_bits_irqsoff(mask);
+ local_irq_restore(flags);
+}
+
+#ifndef MODULE
+/*
* 6 because 6 should be plenty and struct tlb_state will fit in two cache
* lines.
*/
@@ -129,76 +178,18 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct tl
bool nmi_uaccess_okay(void);
#define nmi_uaccess_okay nmi_uaccess_okay
-void cr4_update_irqsoff(unsigned long set, unsigned long clear);
-unsigned long cr4_read_shadow(void);
-
/* Initialize cr4 shadow for this CPU. */
static inline void cr4_init_shadow(void)
{
this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
}
-/* Set in this cpu's CR4. */
-static inline void cr4_set_bits_irqsoff(unsigned long mask)
-{
- cr4_update_irqsoff(mask, 0);
-}
-
-/* Clear in this cpu's CR4. */
-static inline void cr4_clear_bits_irqsoff(unsigned long mask)
-{
- cr4_update_irqsoff(0, mask);
-}
-
-/* Set in this cpu's CR4. */
-static inline void cr4_set_bits(unsigned long mask)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- cr4_set_bits_irqsoff(mask);
- local_irq_restore(flags);
-}
-
-/* Clear in this cpu's CR4. */
-static inline void cr4_clear_bits(unsigned long mask)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- cr4_clear_bits_irqsoff(mask);
- local_irq_restore(flags);
-}
-
extern unsigned long mmu_cr4_features;
extern u32 *trampoline_cr4_features;
extern void initialize_tlbstate_and_flush(void);
/*
- * flush everything
- */
-static inline void __flush_tlb_all(void)
-{
- /*
- * This is to catch users with enabled preemption and the PGE feature
- * and don't trigger the warning in __native_flush_tlb().
- */
- VM_WARN_ON_ONCE(preemptible());
-
- if (boot_cpu_has(X86_FEATURE_PGE)) {
- flush_tlb_global();
- } else {
- /*
- * !PGE -> !PCID (setup_pcid()), thus every flush is total.
- */
- flush_tlb_local();
- }
-}
-
-#define TLB_FLUSH_ALL -1UL
-
-/*
* TLB flushing:
*
* - flush_tlb_all() flushes all processes TLBs
@@ -236,6 +227,15 @@ struct flush_tlb_info {
bool freed_tables;
};
+void flush_tlb_one_user(unsigned long addr);
+void flush_tlb_one_kernel(unsigned long addr);
+void flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info);
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#endif
+
#define flush_tlb_mm(mm) \
flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)
@@ -276,4 +276,6 @@ static inline void arch_tlbbatch_add_mm(
extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
+#endif /* !MODULE */
+
#endif /* _ASM_X86_TLBFLUSH_H */
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -970,7 +970,6 @@ void __init zone_sizes_init(void)
.next_asid = 1,
.cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */
};
-EXPORT_PER_CPU_SYMBOL(cpu_tlbstate);
void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
{
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