* + userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch added to mm-unstable branch
@ 2023-03-31 22:09 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2023-03-31 22:09 UTC (permalink / raw
To: mm-commits, willy, wangkefeng.wang, vishal.moola, sunnanyong,
sidhartha.kumar, muchun.song, mike.kravetz, zhangpeng362, akpm
The patch titled
Subject: userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
has been added to the -mm mm-unstable branch. Its filename is
userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: ZhangPeng <zhangpeng362@huawei.com>
Subject: userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
Date: Fri, 31 Mar 2023 17:39:33 +0800
kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]
Let's replace the kmap() and kmap_atomic() with kmap_local_page() in
copy_huge_page_from_user(). When allow_pagefault is false, disable page
faults to prevent potential deadlock.[2]
Link:https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/ [1]
Link: https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com [2]
Link: https://lkml.kernel.org/r/20230331093937.945725-3-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memory.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
--- a/mm/memory.c~userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user
+++ a/mm/memory.c
@@ -5880,16 +5880,14 @@ long copy_huge_page_from_user(struct pag
for (i = 0; i < pages_per_huge_page; i++) {
subpage = nth_page(dst_page, i);
- if (allow_pagefault)
- page_kaddr = kmap(subpage);
- else
- page_kaddr = kmap_atomic(subpage);
+ page_kaddr = kmap_local_page(subpage);
+ if (!allow_pagefault)
+ pagefault_disable();
rc = copy_from_user(page_kaddr,
usr_src + i * PAGE_SIZE, PAGE_SIZE);
- if (allow_pagefault)
- kunmap(subpage);
- else
- kunmap_atomic(page_kaddr);
+ if (!allow_pagefault)
+ pagefault_enable();
+ kunmap_local(page_kaddr);
ret_val -= (PAGE_SIZE - rc);
if (rc)
_
Patches currently in -mm which might be from zhangpeng362@huawei.com are
userfaultfd-convert-mfill_atomic_pte_copy-to-use-a-folio.patch
userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
userfaultfd-convert-copy_huge_page_from_user-to-copy_folio_from_user.patch
userfaultfd-convert-mfill_atomic_hugetlb-to-use-a-folio.patch
mm-convert-copy_user_huge_page-to-copy_user_folio.patch
userfaultfd-convert-mfill_atomic-to-use-a-folio.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
* + userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch added to mm-unstable branch
@ 2023-04-11 3:47 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2023-04-11 3:47 UTC (permalink / raw
To: mm-commits, willy, wangkefeng.wang, vishal.moola, sunnanyong,
sidhartha.kumar, muchun.song, mike.kravetz, zhangpeng362, akpm
The patch titled
Subject: userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
has been added to the -mm mm-unstable branch. Its filename is
userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: ZhangPeng <zhangpeng362@huawei.com>
Subject: userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
Date: Mon, 10 Apr 2023 21:39:28 +0800
kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]
Let's replace the kmap() and kmap_atomic() with kmap_local_page() in
copy_huge_page_from_user(). When allow_pagefault is false, disable page
faults to prevent potential deadlock.[2]
[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com
Link: https://lkml.kernel.org/r/20230410133932.32288-3-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memory.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
--- a/mm/memory.c~userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user
+++ a/mm/memory.c
@@ -5866,16 +5866,14 @@ long copy_huge_page_from_user(struct pag
for (i = 0; i < pages_per_huge_page; i++) {
subpage = nth_page(dst_page, i);
- if (allow_pagefault)
- page_kaddr = kmap(subpage);
- else
- page_kaddr = kmap_atomic(subpage);
+ page_kaddr = kmap_local_page(subpage);
+ if (!allow_pagefault)
+ pagefault_disable();
rc = copy_from_user(page_kaddr,
usr_src + i * PAGE_SIZE, PAGE_SIZE);
- if (allow_pagefault)
- kunmap(subpage);
- else
- kunmap_atomic(page_kaddr);
+ if (!allow_pagefault)
+ pagefault_enable();
+ kunmap_local(page_kaddr);
ret_val -= (PAGE_SIZE - rc);
if (rc)
_
Patches currently in -mm which might be from zhangpeng362@huawei.com are
mm-madvise-use-vma_lookup-instead-of-find_vma.patch
userfaultfd-convert-mfill_atomic_pte_copy-to-use-a-folio.patch
userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch
userfaultfd-convert-copy_huge_page_from_user-to-copy_folio_from_user.patch
userfaultfd-convert-mfill_atomic_hugetlb-to-use-a-folio.patch
mm-convert-copy_user_huge_page-to-copy_user_large_folio.patch
userfaultfd-convert-mfill_atomic-to-use-a-folio.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2023-04-11 3:47 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-03-31 22:09 + userfaultfd-use-kmap_local_page-in-copy_huge_page_from_user.patch added to mm-unstable branch Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2023-04-11 3:47 Andrew Morton
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.