AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-11-24 08:40:53 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

userfaultfd: non-cooperative: add madvise() event for MADV_FREE request

Browse Source 
MADV_FREE is identical to MADV_DONTNEED from the point of view of uffd
monitor.  The monitor has to stop handling #PF events in the range being
freed.  We are reusing userfaultfd_remove callback along with the logic
required to re-get and re-validate the VMA which may change or disappear
because userfaultfd_remove releases mmap_sem.

Link: http://lkml.kernel.org/r/1497876311-18615-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2017-07-10 15:49:02 -07:00 committed by Linus Torvalds
parent 76b6f9b7ed
commit 230ca982ba
1 changed files with 22 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
mm/madvise.c
View File

@ -451,9 +451,6 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
struct mm_struct *mm = vma->vm_mm;
struct mmu_gather tlb;
if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
return -EINVAL;
/* MADV_FREE works for only anon vma at the moment */
if (!vma_is_anonymous(vma))
return -EINVAL;
@ -477,14 +474,6 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
return 0;
}
static long madvise_free(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
*prev = vma;
return madvise_free_single_vma(vma, start, end);
}
/*
* Application no longer needs these pages. If the pages are dirty,
* it's OK to just throw them away. The app will be more careful about
@ -504,9 +493,17 @@ static long madvise_free(struct vm_area_struct *vma,
* An interface that causes the system to free clean pages and flush
* dirty pages is already available as msync(MS_INVALIDATE).
*/
static long madvise_dontneed(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
static long madvise_dontneed_single_vma(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
zap_page_range(vma, start, end - start);
return 0;
}
static long madvise_dontneed_free(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end,
int behavior)
{
*prev = vma;
if (!can_madv_dontneed_vma(vma))
@ -526,7 +523,8 @@ static long madvise_dontneed(struct vm_area_struct *vma,
* is also < vma->vm_end. If start <
* vma->vm_start it means an hole materialized
* in the user address space within the
* virtual range passed to MADV_DONTNEED.
* virtual range passed to MADV_DONTNEED
* or MADV_FREE.
*/
return -ENOMEM;
}
@ -537,7 +535,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
* Don't fail if end > vma->vm_end. If the old
* vma was splitted while the mmap_sem was
* released the effect of the concurrent
* operation may not cause MADV_DONTNEED to
* operation may not cause madvise() to
* have an undefined result. There may be an
* adjacent next vma that we'll walk
* next. userfaultfd_remove() will generate an
@ -549,8 +547,13 @@ static long madvise_dontneed(struct vm_area_struct *vma,
}
VM_WARN_ON(start >= end);
}
zap_page_range(vma, start, end - start);
return 0;
if (behavior == MADV_DONTNEED)
return madvise_dontneed_single_vma(vma, start, end);
else if (behavior == MADV_FREE)
return madvise_free_single_vma(vma, start, end);
else
return -EINVAL;
}
/*
@ -656,9 +659,8 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
case MADV_WILLNEED:
return madvise_willneed(vma, prev, start, end);
case MADV_FREE:
return madvise_free(vma, prev, start, end);
case MADV_DONTNEED:
return madvise_dontneed(vma, prev, start, end);
return madvise_dontneed_free(vma, prev, start, end, behavior);
default:
return madvise_behavior(vma, prev, start, end, behavior);
}