alloc_tag: introduce clear_page_tag_ref() helper function

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/[email protected]
Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <[email protected]>
Suggested-by: David Hildenbrand <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Sourav Panda <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>	[6.10]
Signed-off-by: Andrew Morton <[email protected]>

diff --git a/include/linux/pgalloc_tag.h b/include/linux/pgalloc_tag.h
index 18cd0c0c73d93d9c80ba46b708763dad3c15752e..207f0c83c8e9750ac7050cc488f1618a69c4fd5c 100644 (file)
--- a/include/linux/pgalloc_tag.h
+++ b/include/linux/pgalloc_tag.h
@@ -43,6 +43,18 @@ static inline void put_page_tag_ref(union codetag_ref *ref)
        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(struct alloc_tag *tag, unsigned int nr)
 
 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) {}

diff --git a/mm/mm_init.c b/mm/mm_init.c
index f9a60ffc5532068263ddcc5dc273fd884145d14e..adc3127573cd45da088556f97a91c8a89e440a5e 100644 (file)
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2459,15 +2459,7 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn,
        }
 
        /* 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);
 }
 

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8747087acee3b3e5e42d67a55b5f8d33cdd35f8c..c565de8f48e9d8cd10bfb53988373350f9c98ec3 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5815,14 +5815,7 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
 
 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);