shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-03-24 19:40:21 +09:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'odroidc2-3.14.y' of github.com:hardkernel/linux into odroidc2-3.14.y

Browse Source
This commit is contained in:
Mauro (mdrjr) Ribeiro
2016-10-24 12:46:11 -02:00
parent 9520f75177 2b45c3268b
commit 8a68ab963a
2 changed files with 13 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/mm.h
View File

@@ -2000,6 +2000,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma,
#define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
#define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
#define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
#define FOLL_COW 0x4000 /* internal GUP flag */
typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
void *data);

14
mm/memory.c
View File

@@ -1448,6 +1448,16 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
}
EXPORT_SYMBOL_GPL(zap_vma_ptes);
/*
* FOLL_FORCE can write to even unwritable pte's, but only
* after we've gone through a COW cycle and they are dirty.
*/
static inline bool can_follow_write_pte(pte_t pte, unsigned int flags)
{
return pte_write(pte) ||
((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte));
}
/**
* follow_page_mask - look up a page descriptor from a user-virtual address
* @vma: vm_area_struct mapping @address
@@ -1568,7 +1578,7 @@ split_fallthrough:
}
if ((flags & FOLL_NUMA) && pte_numa(pte))
goto no_page;
if ((flags & FOLL_WRITE) && !pte_write(pte))
if ((flags & FOLL_WRITE) && !can_follow_write_pte(pte, flags))
goto unlock;
page = vm_normal_page(vma, address, pte);
@@ -1876,7 +1886,7 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
*/
if ((ret & VM_FAULT_WRITE) &&
!(vma->vm_flags & VM_WRITE))
foll_flags &= ~FOLL_WRITE;
foll_flags |= FOLL_COW;
cond_resched();
}