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-rw-r--r--mm/madvise.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/mm/madvise.c b/mm/madvise.c
index 21261ff0466f..375cf32087e4 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* linux/mm/madvise.c
*
@@ -625,18 +626,26 @@ static int madvise_inject_error(int behavior,
{
struct page *page;
struct zone *zone;
+ unsigned int order;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- for (; start < end; start += PAGE_SIZE <<
- compound_order(compound_head(page))) {
+
+ for (; start < end; start += PAGE_SIZE << order) {
int ret;
ret = get_user_pages_fast(start, 1, 0, &page);
if (ret != 1)
return ret;
+ /*
+ * When soft offlining hugepages, after migrating the page
+ * we dissolve it, therefore in the second loop "page" will
+ * no longer be a compound page, and order will be 0.
+ */
+ order = compound_order(compound_head(page));
+
if (PageHWPoison(page)) {
put_page(page);
continue;
@@ -749,6 +758,9 @@ madvise_behavior_valid(int behavior)
* MADV_DONTFORK - omit this area from child's address space when forking:
* typically, to avoid COWing pages pinned by get_user_pages().
* MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking.
+ * MADV_WIPEONFORK - present the child process with zero-filled memory in this
+ * range after a fork.
+ * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK
* MADV_HWPOISON - trigger memory error handler as if the given memory range
* were corrupted by unrecoverable hardware memory failure.
* MADV_SOFT_OFFLINE - try to soft-offline the given range of memory.
@@ -769,7 +781,9 @@ madvise_behavior_valid(int behavior)
* zero - success
* -EINVAL - start + len < 0, start is not page-aligned,
* "behavior" is not a valid value, or application
- * is attempting to release locked or shared pages.
+ * is attempting to release locked or shared pages,
+ * or the specified address range includes file, Huge TLB,
+ * MAP_SHARED or VMPFNMAP range.
* -ENOMEM - addresses in the specified range are not currently
* mapped, or are outside the AS of the process.
* -EIO - an I/O error occurred while paging in data.