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  1. 06 3月, 2023 2 次提交
  3. 25 2月, 2023 1 次提交
  5. 17 2月, 2023 6 次提交
  7. 13 2月, 2023 2 次提交
  9. 09 2月, 2023 3 次提交
  11. 31 1月, 2023 2 次提交
  13. 19 1月, 2023 2 次提交
  15. 16 1月, 2023 1 次提交
  17. 04 1月, 2023 4 次提交
  19. 08 12月, 2022 6 次提交
  21. 02 12月, 2022 2 次提交
    • D
      mm/hugetlb: fix hugetlb not supporting softdirty tracking · 9742b1b6
      由 David Hildenbrand 提交于 
      stable inclusion
from stable-v5.10.140
commit 62af37c5cd7f5fd071086cab645844bf5bcdc0ef
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I63FTT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=62af37c5cd7f5fd071086cab645844bf5bcdc0ef

--------------------------------

commit f96f7a40 upstream.

Patch series "mm/hugetlb: fix write-fault handling for shared mappings", v2.

I observed that hugetlb does not support/expect write-faults in shared
mappings that would have to map the R/O-mapped page writable -- and I
found two case where we could currently get such faults and would
erroneously map an anon page into a shared mapping.

Reproducers part of the patches.

I propose to backport both fixes to stable trees.  The first fix needs a
small adjustment.

This patch (of 2):

Staring at hugetlb_wp(), one might wonder where all the logic for shared
mappings is when stumbling over a write-protected page in a shared
mapping.  In fact, there is none, and so far we thought we could get away
with that because e.g., mprotect() should always do the right thing and
map all pages directly writable.

Looks like we were wrong:

--------------------------------------------------------------------------
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sys/mman.h>

 #define HUGETLB_SIZE (2 * 1024 * 1024u)

 static void clear_softdirty(void)
 {
         int fd = open("/proc/self/clear_refs", O_WRONLY);
         const char *ctrl = "4";
         int ret;

         if (fd < 0) {
                 fprintf(stderr, "open(clear_refs) failed\n");
                 exit(1);
         }
         ret = write(fd, ctrl, strlen(ctrl));
         if (ret != strlen(ctrl)) {
                 fprintf(stderr, "write(clear_refs) failed\n");
                 exit(1);
         }
         close(fd);
 }

 int main(int argc, char **argv)
 {
         char *map;
         int fd;

         fd = open("/dev/hugepages/tmp", O_RDWR | O_CREAT);
         if (!fd) {
                 fprintf(stderr, "open() failed\n");
                 return -errno;
         }
         if (ftruncate(fd, HUGETLB_SIZE)) {
                 fprintf(stderr, "ftruncate() failed\n");
                 return -errno;
         }

         map = mmap(NULL, HUGETLB_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
         if (map == MAP_FAILED) {
                 fprintf(stderr, "mmap() failed\n");
                 return -errno;
         }

         *map = 0;

         if (mprotect(map, HUGETLB_SIZE, PROT_READ)) {
                 fprintf(stderr, "mmprotect() failed\n");
                 return -errno;
         }

         clear_softdirty();

         if (mprotect(map, HUGETLB_SIZE, PROT_READ|PROT_WRITE)) {
                 fprintf(stderr, "mmprotect() failed\n");
                 return -errno;
         }

         *map = 0;

         return 0;
 }
--------------------------------------------------------------------------

Above test fails with SIGBUS when there is only a single free hugetlb page.
 # echo 1 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
 # ./test
 Bus error (core dumped)

And worse, with sufficient free hugetlb pages it will map an anonymous page
into a shared mapping, for example, messing up accounting during unmap
and breaking MAP_SHARED semantics:
 # echo 2 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
 # ./test
 # cat /proc/meminfo | grep HugePages_
 HugePages_Total:       2
 HugePages_Free:        1
 HugePages_Rsvd:    18446744073709551615
 HugePages_Surp:        0

Reason in this particular case is that vma_wants_writenotify() will
return "true", removing VM_SHARED in vma_set_page_prot() to map pages
write-protected. Let's teach vma_wants_writenotify() that hugetlb does not
support softdirty tracking.

Link: https://lkml.kernel.org/r/20220811103435.188481-1-david@redhat.com
Link: https://lkml.kernel.org/r/20220811103435.188481-2-david@redhat.com
Fixes: 64e45507 ("mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared")
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jamie Liu <jamieliu@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>	[3.18+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
      9742b1b6
    • M
      mm/huge_memory.c: use helper function migration_entry_to_page() · 5dabdf42
      由 Miaohe Lin 提交于 
      stable inclusion
from stable-v5.10.140
commit c7c77185fa3e9f8c3358426c2584a5b1dc1fdf0f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I63FTT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c7c77185fa3e9f8c3358426c2584a5b1dc1fdf0f

--------------------------------

[ Upstream commit a44f89dc ]

It's more recommended to use helper function migration_entry_to_page()
to get the page via migration entry.  We can also enjoy the PageLocked()
check there.

Link: https://lkml.kernel.org/r/20210318122722.13135-7-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Thomas Hellstrm (Intel) <thomas_os@shipmail.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: yuleixzhang <yulei.kernel@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
      5dabdf42
  23. 01 12月, 2022 5 次提交
  25. 30 11月, 2022 2 次提交
  27. 24 11月, 2022 1 次提交
  29. 23 11月, 2022 1 次提交
    • L
      cgroup: support cgroup writeback on cgroupv1 · 644547a9
      由 Lu Jialin 提交于 
      hulkl inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZG61

-------------------------------

In cgroupv1, cgroup writeback is not supproted for two problems:
1) Blkcg_css and memcg_css are mounted on different cgroup trees.
   Therefore, blkcg_css cannot be found according to a certain memcg_css.
2) Buffer I/O is worked by kthread, which is in the root_blkcg.
   Therefore, blkcg cannot limit wbps and wiops of buffer I/O.

We solve the two problems to support cgroup writeback on cgroupv1.
1) A memcg is attached to the blkcg_root css when the memcg was created.
2) We add a member "wb_blkio_ino" in mem_cgroup_legacy_files.
   User can attach a memcg to a cerntain blkcg through echo the file
   inode of the blkcg into the wb_blkio of the memcg.
3) inode_cgwb_enabled() return true when memcg and io are both mounted
   on cgroupv2 or both on cgroupv1.
4) Buffer I/O can find a blkcg according to its memcg.

Thus, a memcg can find a certain blkcg, and cgroup writeback can be
supported on cgroupv1.
Signed-off-by: NLu Jialin <lujialin4@huawei.com>
      644547a9