linux/include/asm-generic/hugetlb.h
Baolin Wang ae07562909 mm: change huge_ptep_clear_flush() to return the original pte
Patch series "Fix CONT-PTE/PMD size hugetlb issue when unmapping or migrating", v4.

presently, migrating a hugetlb page or unmapping a poisoned hugetlb page,
we'll use ptep_clear_flush() and set_pte_at() to nuke the page table entry
and remap it, and this is incorrect for CONT-PTE or CONT-PMD size hugetlb
page, which will cause potential data consistent issue.  This patch set
will change to use hugetlb related APIs to fix this issue.

Note: Mike pointed out the huge_ptep_get() will only return the one
specific value, and it would not take into account the dirty or young bits
of CONT-PTE/PMDs like the huge_ptep_get_and_clear() [1].  This
inconsistent issue is not introduced by this patch set, and this issue
will be addressed in another thread [2].  Meanwhile the uffd for hugetlb
case [3] pointed out by Gerald also needs another patch to address.

[1] https://lore.kernel.org/linux-mm/85bd80b4-b4fd-0d3f-a2e5-149559f2f387@oracle.com/
[2] https://lore.kernel.org/all/cover.1651998586.git.baolin.wang@linux.alibaba.com/
[3] https://lore.kernel.org/linux-mm/20220503120343.6264e126@thinkpad/


This patch (of 3):

It is incorrect to use ptep_clear_flush() to nuke a hugetlb page table
when unmapping or migrating a hugetlb page, and will change to use
huge_ptep_clear_flush() instead in the following patches.

So this is a preparation patch, which changes the huge_ptep_clear_flush()
to return the original pte to help to nuke a hugetlb page table.

[baolin.wang@linux.alibaba.com: fix build in several more architectures]
  Link: https://lkml.kernel.org/r/0009a4cd-2826-e8be-e671-f050d4f18d5d@linux.alibaba.com
[sfr@canb.auug.org.au: fixup]
  Link: https://lkml.kernel.org/r/20220511181531.7f27a5c1@canb.auug.org.au
Link: https://lkml.kernel.org/r/cover.1652270205.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/20f77ddab90baa249bd24504c413189b82acde69.1652270205.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/cover.1652147571.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/dcf065868cce35bceaf138613ad27f17bb7c0c19.1652147571.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 16:48:55 -07:00

161 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_HUGETLB_H
#define _ASM_GENERIC_HUGETLB_H
#include <linux/swap.h>
#include <linux/swapops.h>
static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
{
return mk_pte(page, pgprot);
}
static inline unsigned long huge_pte_write(pte_t pte)
{
return pte_write(pte);
}
static inline unsigned long huge_pte_dirty(pte_t pte)
{
return pte_dirty(pte);
}
static inline pte_t huge_pte_mkwrite(pte_t pte)
{
return pte_mkwrite(pte);
}
static inline pte_t huge_pte_mkdirty(pte_t pte)
{
return pte_mkdirty(pte);
}
static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
{
return pte_modify(pte, newprot);
}
static inline pte_t huge_pte_mkuffd_wp(pte_t pte)
{
return pte_mkuffd_wp(pte);
}
static inline pte_t huge_pte_clear_uffd_wp(pte_t pte)
{
return pte_clear_uffd_wp(pte);
}
static inline int huge_pte_uffd_wp(pte_t pte)
{
return pte_uffd_wp(pte);
}
#ifndef __HAVE_ARCH_HUGE_PTE_CLEAR
static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, unsigned long sz)
{
pte_clear(mm, addr, ptep);
}
#endif
#ifndef __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
free_pgd_range(tlb, addr, end, floor, ceiling);
}
#endif
#ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
set_pte_at(mm, addr, ptep, pte);
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
return ptep_get_and_clear(mm, addr, ptep);
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
return ptep_clear_flush(vma, addr, ptep);
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTE_NONE
static inline int huge_pte_none(pte_t pte)
{
return pte_none(pte);
}
#endif
/* Please refer to comments above pte_none_mostly() for the usage */
static inline int huge_pte_none_mostly(pte_t pte)
{
return huge_pte_none(pte) || is_pte_marker(pte);
}
#ifndef __HAVE_ARCH_HUGE_PTE_WRPROTECT
static inline pte_t huge_pte_wrprotect(pte_t pte)
{
return pte_wrprotect(pte);
}
#endif
#ifndef __HAVE_ARCH_PREPARE_HUGEPAGE_RANGE
static inline int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
struct hstate *h = hstate_file(file);
if (len & ~huge_page_mask(h))
return -EINVAL;
if (addr & ~huge_page_mask(h))
return -EINVAL;
return 0;
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
ptep_set_wrprotect(mm, addr, ptep);
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t pte, int dirty)
{
return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
}
#endif
#ifndef __HAVE_ARCH_HUGE_PTEP_GET
static inline pte_t huge_ptep_get(pte_t *ptep)
{
return ptep_get(ptep);
}
#endif
#ifndef __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED
static inline bool gigantic_page_runtime_supported(void)
{
return IS_ENABLED(CONFIG_ARCH_HAS_GIGANTIC_PAGE);
}
#endif /* __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED */
#endif /* _ASM_GENERIC_HUGETLB_H */