The patch titled
Subject: mm-mincore-make-mincore-more-conservative-v2
has been added to the -mm tree. Its filename is
mm-mincore-make-mincore-more-conservative-v2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mincore-make-mincore-more-conservative-v2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mincore-make-mincore-more-conservative-v2.patch
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 and is updated
there every 3-4 working days
------------------------------------------------------
From: Jiri Kosina <jkosina@xxxxxxx>
Subject: mm-mincore-make-mincore-more-conservative-v2
Link: http://lkml.kernel.org/r/20190312141708.6652-2-vbabka@xxxxxxx
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Josh Snyder <joshs@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/mincore.c~mm-mincore-make-mincore-more-conservative-v2
+++ a/mm/mincore.c
@@ -175,6 +175,12 @@ static inline bool can_do_mincore(struct
return true;
if (!vma->vm_file)
return false;
+ /*
+ * Reveal pagecache information only for non-anonymous mappings that
+ * correspond to the files the calling process could (if tried) open
+ * for writing; otherwise we'd be including shared non-exclusive
+ * mappings, which opens a side channel.
+ */
return inode_owner_or_capable(file_inode(vma->vm_file)) ||
inode_permission(file_inode(vma->vm_file), MAY_WRITE) == 0;
}
@@ -201,7 +207,7 @@ static long do_mincore(unsigned long add
return -ENOMEM;
end = min(vma->vm_end, addr + (pages << PAGE_SHIFT));
if (!can_do_mincore(vma)) {
- unsigned long pages = (end - addr) >> PAGE_SHIFT;
+ unsigned long pages = DIV_ROUND_UP(end - addr, PAGE_SIZE);
memset(vec, 1, pages);
return pages;
}
_
Patches currently in -mm which might be from jkosina@xxxxxxx are
mm-mincore-make-mincore-more-conservative.patch
mm-mincore-make-mincore-more-conservative-v2.patch
