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Message-Id: <20200419203336.319268126@linutronix.de>
Date: Sun, 19 Apr 2020 22:31:44 +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>,
Juergen Gross <jgross@...e.com>,
Thomas Lendacky <Thomas.Lendacky@....com>,
Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [patch 07/15] x86/tlb: Move __flush_tlb_one_user() out of line
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.
The various TLB flush functions need access to cpu_tlbstate. As third step
move _flush_tlb_one_user() out of line and hide the native function. The
latter can be static when CONFIG_PARAVIRT is disabled.
Consolidate the name space while at it and remove the pointless extra
wrapper in the paravirt code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Juergen Gross <jgross@...e.com>
---
arch/x86/include/asm/paravirt.h | 1
arch/x86/include/asm/tlbflush.h | 53 +--------------------------------------
arch/x86/kernel/paravirt.c | 5 ---
arch/x86/mm/tlb.c | 54 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 57 insertions(+), 56 deletions(-)
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -49,6 +49,7 @@ static inline void slow_down_io(void)
void native_flush_tlb_local(void);
void native_flush_tlb_global(void);
+void native_flush_tlb_one_user(unsigned long addr);
static inline void __flush_tlb_local(void)
{
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -142,11 +142,10 @@ static inline unsigned long build_cr3_no
void flush_tlb_local(void);
void flush_tlb_global(void);
+void flush_tlb_one_user(unsigned long addr);
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
-#else
-#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
#endif
struct tlb_context {
@@ -346,54 +345,6 @@ static inline void cr4_set_bits_and_upda
extern void initialize_tlbstate_and_flush(void);
/*
- * Given an ASID, flush the corresponding user ASID. We can delay this
- * until the next time we switch to it.
- *
- * See SWITCH_TO_USER_CR3.
- */
-static inline void invalidate_user_asid(u16 asid)
-{
- /* There is no user ASID if address space separation is off */
- if (!IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
- return;
-
- /*
- * We only have a single ASID if PCID is off and the CR3
- * write will have flushed it.
- */
- if (!cpu_feature_enabled(X86_FEATURE_PCID))
- return;
-
- if (!static_cpu_has(X86_FEATURE_PTI))
- return;
-
- __set_bit(kern_pcid(asid),
- (unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
-}
-
-/*
- * flush one page in the user mapping
- */
-static inline void __native_flush_tlb_one_user(unsigned long addr)
-{
- u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
-
- asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
-
- if (!static_cpu_has(X86_FEATURE_PTI))
- return;
-
- /*
- * Some platforms #GP if we call invpcid(type=1/2) before CR4.PCIDE=1.
- * Just use invalidate_user_asid() in case we are called early.
- */
- if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE))
- invalidate_user_asid(loaded_mm_asid);
- else
- invpcid_flush_one(user_pcid(loaded_mm_asid), addr);
-}
-
-/*
* flush everything
*/
static inline void __flush_tlb_all(void)
@@ -432,7 +383,7 @@ static inline void __flush_tlb_one_kerne
* kernel address space and for its usermode counterpart, but it does
* not flush it for other address spaces.
*/
- __flush_tlb_one_user(addr);
+ flush_tlb_one_user(addr);
if (!static_cpu_has(X86_FEATURE_PTI))
return;
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -160,11 +160,6 @@ unsigned paravirt_patch_insns(void *insn
return insn_len;
}
-static void native_flush_tlb_one_user(unsigned long addr)
-{
- __native_flush_tlb_one_user(addr);
-}
-
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -24,6 +24,7 @@
# define STATIC_NOPV static
# define __flush_tlb_local native_flush_tlb_local
# define __flush_tlb_global native_flush_tlb_global
+# define __flush_tlb_one_user(addr) native_flush_tlb_one_user(addr)
#endif
/*
@@ -118,6 +119,32 @@ static void choose_new_asid(struct mm_st
*need_flush = true;
}
+/*
+ * Given an ASID, flush the corresponding user ASID. We can delay this
+ * until the next time we switch to it.
+ *
+ * See SWITCH_TO_USER_CR3.
+ */
+static inline void invalidate_user_asid(u16 asid)
+{
+ /* There is no user ASID if address space separation is off */
+ if (!IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
+ return;
+
+ /*
+ * We only have a single ASID if PCID is off and the CR3
+ * write will have flushed it.
+ */
+ if (!cpu_feature_enabled(X86_FEATURE_PCID))
+ return;
+
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ __set_bit(kern_pcid(asid),
+ (unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
+}
+
static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush)
{
unsigned long new_mm_cr3;
@@ -892,6 +919,33 @@ unsigned long __get_current_cr3_fast(voi
EXPORT_SYMBOL_GPL(__get_current_cr3_fast);
/*
+ * Flush one page in the user mapping
+ */
+STATIC_NOPV void native_flush_tlb_one_user(unsigned long addr)
+{
+ u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
+
+ asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ /*
+ * Some platforms #GP if we call invpcid(type=1/2) before CR4.PCIDE=1.
+ * Just use invalidate_user_asid() in case we are called early.
+ */
+ if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE))
+ invalidate_user_asid(loaded_mm_asid);
+ else
+ invpcid_flush_one(user_pcid(loaded_mm_asid), addr);
+}
+
+void flush_tlb_one_user(unsigned long addr)
+{
+ __flush_tlb_one_user(addr);
+}
+
+/*
* Flush everything
*/
STATIC_NOPV void native_flush_tlb_global(void)
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