The patch titled
Subject: alloc_tag: introduce clear_page_tag_ref() helper function
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: alloc_tag: introduce clear_page_tag_ref() helper function
Date: Tue, 13 Aug 2024 08:07:56 -0700
In several cases we are freeing pages which were not allocated using
common page allocators. For such cases, in order to keep allocation
accounting correct, we should clear the page tag to indicate that the page
being freed is expected to not have a valid allocation tag. Introduce
clear_page_tag_ref() helper function to be used for this.
Link: https://lkml.kernel.org/r/20240813150758.855881-1-surenb@xxxxxxxxxx
Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [6.10]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pgalloc_tag.h | 13 +++++++++++++
mm/mm_init.c | 10 +---------
mm/page_alloc.c | 9 +--------
3 files changed, 15 insertions(+), 17 deletions(-)
--- a/include/linux/pgalloc_tag.h~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/include/linux/pgalloc_tag.h
@@ -43,6 +43,18 @@ static inline void put_page_tag_ref(unio
page_ext_put(page_ext_from_codetag_ref(ref));
}
+static inline void clear_page_tag_ref(struct page *page)
+{
+ if (mem_alloc_profiling_enabled()) {
+ union codetag_ref *ref = get_page_tag_ref(page);
+
+ if (ref) {
+ set_codetag_empty(ref);
+ put_page_tag_ref(ref);
+ }
+ }
+}
+
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr)
{
@@ -126,6 +138,7 @@ static inline void pgalloc_tag_sub_pages
static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; }
static inline void put_page_tag_ref(union codetag_ref *ref) {}
+static inline void clear_page_tag_ref(struct page *page) {}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr) {}
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}
--- a/mm/mm_init.c~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/mm/mm_init.c
@@ -2459,15 +2459,7 @@ void __init memblock_free_pages(struct p
}
/* pages were reserved and not allocated */
- if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
-
- if (ref) {
- set_codetag_empty(ref);
- put_page_tag_ref(ref);
- }
- }
-
+ clear_page_tag_ref(page);
__free_pages_core(page, order, MEMINIT_EARLY);
}
--- a/mm/page_alloc.c~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/mm/page_alloc.c
@@ -5815,14 +5815,7 @@ unsigned long free_reserved_area(void *s
void free_reserved_page(struct page *page)
{
- if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
-
- if (ref) {
- set_codetag_empty(ref);
- put_page_tag_ref(ref);
- }
- }
+ clear_page_tag_ref(page);
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
alloc_tag-mark-pages-reserved-during-cma-activation-as-not-tagged.patch
