OERV-BSP/kernel-spacemit-k1
4
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

hugetlbfs: extend hugetlb_vma_lock to private VMAs

Browse Source 
Extend the locking scheme used to protect shared hugetlb mappings from
truncate vs page fault races, in order to protect private hugetlb mappings
(with resv_map) against MADV_DONTNEED.

Add a read-write semaphore to the resv_map data structure, and use that
from the hugetlb_vma_(un)lock_* functions, in preparation for closing the
race between MADV_DONTNEED and page faults.

Link: https://lkml.kernel.org/r/20231006040020.3677377-3-riel@surriel.com
Fixes: 04ada095dc ("hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Rik van Riel
2023-10-05 23:59:07 -04:00
committed by Andrew Morton
parent 92fe9dcbe4
commit bf4916922c
2 changed files with 43 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/hugetlb.h
View File

@@ -60,6 +60,7 @@ struct resv_map {
long adds_in_progress;
struct list_head region_cache;
long region_cache_count;
struct rw_semaphore rw_sema;
#ifdef CONFIG_CGROUP_HUGETLB
/*
* On private mappings, the counter to uncharge reservations is stored
@@ -1233,6 +1234,11 @@ static inline bool __vma_shareable_lock(struct vm_area_struct *vma)
return (vma->vm_flags & VM_MAYSHARE) && vma->vm_private_data;
}
static inline bool __vma_private_lock(struct vm_area_struct *vma)
{
return (!(vma->vm_flags & VM_MAYSHARE)) && vma->vm_private_data;
}
/*
* Safe version of huge_pte_offset() to check the locks. See comments
* above huge_pte_offset().