The patch titled
Subject: uprobe-use-original-page-when-all-uprobes-are-removed-v2
has been added to the -mm tree. Its filename is
uprobe-use-original-page-when-all-uprobes-are-removed-v2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/uprobe-use-original-page-when-all-uprobes-are-removed-v2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/uprobe-use-original-page-when-all-uprobes-are-removed-v2.patch
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------------------------------------------------------
From: Song Liu <songliubraving@xxxxxx>
Subject: uprobe-use-original-page-when-all-uprobes-are-removed-v2
Link: http://lkml.kernel.org/r/20190730193100.2295258-1-songliubraving@xxxxxx
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Suggested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew.wilcox@xxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/events/uprobes.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
--- a/kernel/events/uprobes.c~uprobe-use-original-page-when-all-uprobes-are-removed-v2
+++ a/kernel/events/uprobes.c
@@ -192,7 +192,9 @@ static int __replace_page(struct vm_area
page_add_new_anon_rmap(new_page, vma, addr, false);
mem_cgroup_commit_charge(new_page, memcg, false, false);
lru_cache_add_active_or_unevictable(new_page, vma);
- }
+ } else
+ /* no new page, just dec_mm_counter for old_page */
+ dec_mm_counter(mm, MM_ANONPAGES);
if (!PageAnon(old_page)) {
dec_mm_counter(mm, mm_counter_file(old_page));
@@ -496,6 +498,10 @@ retry:
ref_ctr_updated = 1;
}
+ ret = 0;
+ if (!is_register && !PageAnon(old_page))
+ goto put_old;
+
ret = anon_vma_prepare(vma);
if (ret)
goto put_old;
@@ -509,11 +515,12 @@ retry:
copy_highpage(new_page, old_page);
copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
- /* try orig_page only for unregister and anonymous old_page */
- if (!is_register && PageAnon(old_page)) {
+ if (!is_register) {
struct page *orig_page;
pgoff_t index;
+ VM_BUG_ON_PAGE(!PageAnon(old_page), old_page);
+
index = vaddr_to_offset(vma, vaddr & PAGE_MASK) >> PAGE_SHIFT;
orig_page = find_get_page(vma->vm_file->f_inode->i_mapping,
index);
@@ -524,9 +531,6 @@ retry:
/* let go new_page */
put_page(new_page);
new_page = NULL;
-
- /* dec_mm_counter for old_page */
- dec_mm_counter(mm, MM_ANONPAGES);
}
put_page(orig_page);
}
_
Patches currently in -mm which might be from songliubraving@xxxxxx are
mm-move-memcmp_pages-and-pages_identical.patch
uprobe-use-original-page-when-all-uprobes-are-removed.patch
uprobe-use-original-page-when-all-uprobes-are-removed-v2.patch
mm-thp-introduce-foll_split_pmd.patch
uprobe-use-foll_split_pmd-instead-of-foll_split.patch
