Commit 29def599 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/tlb: Move flush_tlb_others() 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.

As a last step, move __flush_tlb_others() out of line and hide the
native function. The latter can be static when CONFIG_PARAVIRT is
disabled.

No functional change.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200421092559.641957686@linutronix.de
parent 58430c5d

arch/x86/include/asm/paravirt.h

+4 −2
Original line number Diff line number Diff line
@@ -50,6 +50,8 @@ 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);

void native_flush_tlb_others(const struct cpumask *cpumask,

			     const struct flush_tlb_info *info);



static inline void __flush_tlb_local(void)

{
@@ -66,7 +68,7 @@ static inline void __flush_tlb_one_user(unsigned long addr) 
	PVOP_VCALL1(mmu.flush_tlb_one_user, addr);

}



static inline void flush_tlb_others(const struct cpumask *cpumask,

static inline void __flush_tlb_others(const struct cpumask *cpumask,

				      const struct flush_tlb_info *info)

{

	PVOP_VCALL2(mmu.flush_tlb_others, cpumask, info);

arch/x86/include/asm/tlbflush.h

+4 −6
Original line number Diff line number Diff line
@@ -140,10 +140,14 @@ static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid) 
	return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH;

}



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>
@@ -418,9 +422,6 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) 
	flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false);

}



void native_flush_tlb_others(const struct cpumask *cpumask,

			     const struct flush_tlb_info *info);



static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)

{

	/*
@@ -442,9 +443,6 @@ static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch, 
extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);



#ifndef CONFIG_PARAVIRT

#define flush_tlb_others(mask, info)	\

	native_flush_tlb_others(mask, info)



#define paravirt_tlb_remove_table(tlb, page) \

	tlb_remove_page(tlb, (void *)(page))

#endif

arch/x86/mm/tlb.c

+9 −2
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
# 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)

# define __flush_tlb_others(msk, info)	native_flush_tlb_others(msk, info)

#endif



/*
@@ -715,7 +716,7 @@ static bool tlb_is_not_lazy(int cpu, void *data) 
	return !per_cpu(cpu_tlbstate.is_lazy, cpu);

}



void native_flush_tlb_others(const struct cpumask *cpumask,

STATIC_NOPV void native_flush_tlb_others(const struct cpumask *cpumask,

					 const struct flush_tlb_info *info)

{

	count_vm_tlb_event(NR_TLB_REMOTE_FLUSH);
@@ -766,6 +767,12 @@ void native_flush_tlb_others(const struct cpumask *cpumask, 
				(void *)info, 1, cpumask);

}



void flush_tlb_others(const struct cpumask *cpumask,

		      const struct flush_tlb_info *info)

{

	__flush_tlb_others(cpumask, info);

}



/*

 * See Documentation/x86/tlb.rst for details.  We choose 33

 * because it is large enough to cover the vast majority (at

CRA Git | Maintained and supported by SUSTech CRA and CCSE