Commit de8c8e52 authored by Tong Tiangen's avatar Tong Tiangen Committed by Andrew Morton
Browse files

mm: page_table_check: add hooks to public helpers 

Move ptep_clear() to the include/linux/pgtable.h and add page table check
relate hooks to some helpers, it's prepare for support page table check
feature on new architecture.

Optimize the implementation of ptep_clear(), page table hooks added page
table check stubs, the interface control should be at stubs, there is no
rationale for doing a IS_ENABLED() check here.

For architectures that do not enable CONFIG_PAGE_TABLE_CHECK, they will
call a fallback page table check stubs[1] when getting their page table
helpers[2] in include/linux/pgtable.h.

[1] page table check stubs defined in include/linux/page_table_check.h
[2] ptep_clear() ptep_get_and_clear()  pmdp_huge_get_and_clear()
pudp_huge_get_and_clear()

Link: https://lkml.kernel.org/r/20220507110114.4128854-4-tongtiangen@huawei.com


Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
Acked-by: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e5a55401

arch/x86/include/asm/pgtable.h

+0 −10
Original line number Diff line number Diff line
@@ -1072,16 +1072,6 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, 
	return pte;

}



#define __HAVE_ARCH_PTEP_CLEAR

static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,

			      pte_t *ptep)

{

	if (IS_ENABLED(CONFIG_PAGE_TABLE_CHECK))

		ptep_get_and_clear(mm, addr, ptep);

	else

		pte_clear(mm, addr, ptep);

}



#define __HAVE_ARCH_PTEP_SET_WRPROTECT

static inline void ptep_set_wrprotect(struct mm_struct *mm,

				      unsigned long addr, pte_t *ptep)

include/linux/pgtable.h

+15 −8
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/bug.h>

#include <linux/errno.h>

#include <asm-generic/pgtable_uffd.h>

#include <linux/page_table_check.h>



#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \

	defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
@@ -259,14 +260,6 @@ static inline int pmdp_clear_flush_young(struct vm_area_struct *vma, 
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#endif



#ifndef __HAVE_ARCH_PTEP_CLEAR

static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,

			      pte_t *ptep)

{

	pte_clear(mm, addr, ptep);

}

#endif



#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR

static inline pte_t ptep_get_and_clear(struct mm_struct *mm,

				       unsigned long address,
@@ -274,10 +267,19 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, 
{

	pte_t pte = *ptep;

	pte_clear(mm, address, ptep);

	page_table_check_pte_clear(mm, address, pte);

	return pte;

}

#endif



#ifndef __HAVE_ARCH_PTEP_CLEAR

static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,

			      pte_t *ptep)

{

	ptep_get_and_clear(mm, addr, ptep);

}

#endif



#ifndef __HAVE_ARCH_PTEP_GET

static inline pte_t ptep_get(pte_t *ptep)

{
@@ -347,7 +349,10 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, 
					    pmd_t *pmdp)

{

	pmd_t pmd = *pmdp;



	pmd_clear(pmdp);

	page_table_check_pmd_clear(mm, address, pmd);



	return pmd;

}

#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
@@ -359,6 +364,8 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, 
	pud_t pud = *pudp;



	pud_clear(pudp);

	page_table_check_pud_clear(mm, address, pud);



	return pud;

}

#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */